Repository: google/guetzli
Branch: master
Commit: 214f2bb42abf
Files: 84
Total size: 454.5 KB
Directory structure:
gitextract_kvasvos7/
├── .gitignore
├── .travis.sh
├── .travis.yml
├── BUILD
├── CONTRIBUTING.md
├── LICENSE
├── Makefile
├── README.md
├── WORKSPACE
├── appveyor.yml
├── external/
│ ├── png.BUILD
│ └── zlib.BUILD
├── fuzz_target.cc
├── guetzli/
│ ├── butteraugli_comparator.cc
│ ├── butteraugli_comparator.h
│ ├── color_transform.h
│ ├── comparator.h
│ ├── dct_double.cc
│ ├── dct_double.h
│ ├── debug_print.cc
│ ├── debug_print.h
│ ├── entropy_encode.cc
│ ├── entropy_encode.h
│ ├── fast_log.h
│ ├── fdct.cc
│ ├── fdct.h
│ ├── gamma_correct.cc
│ ├── gamma_correct.h
│ ├── guetzli.cc
│ ├── idct.cc
│ ├── idct.h
│ ├── jpeg_bit_writer.h
│ ├── jpeg_data.cc
│ ├── jpeg_data.h
│ ├── jpeg_data_decoder.cc
│ ├── jpeg_data_decoder.h
│ ├── jpeg_data_encoder.cc
│ ├── jpeg_data_encoder.h
│ ├── jpeg_data_reader.cc
│ ├── jpeg_data_reader.h
│ ├── jpeg_data_writer.cc
│ ├── jpeg_data_writer.h
│ ├── jpeg_error.h
│ ├── jpeg_huffman_decode.cc
│ ├── jpeg_huffman_decode.h
│ ├── order.inc
│ ├── output_image.cc
│ ├── output_image.h
│ ├── preprocess_downsample.cc
│ ├── preprocess_downsample.h
│ ├── processor.cc
│ ├── processor.h
│ ├── quality.cc
│ ├── quality.h
│ ├── quantize.cc
│ ├── quantize.h
│ ├── score.cc
│ ├── score.h
│ └── stats.h
├── guetzli.make
├── guetzli.sln
├── guetzli.vcxproj
├── guetzli.vcxproj.filters
├── guetzli_static.make
├── guetzli_static.vcxproj
├── guetzli_static.vcxproj.filters
├── premake5.lua
├── snapcraft.yaml
├── tests/
│ ├── golden_checksums.txt
│ ├── golden_test.sh
│ ├── png_checksums.txt
│ └── smoke_test.sh
├── third_party/
│ └── butteraugli/
│ ├── BUILD
│ ├── LICENSE
│ ├── README.md
│ ├── WORKSPACE
│ ├── butteraugli/
│ │ ├── Makefile
│ │ ├── butteraugli.cc
│ │ ├── butteraugli.h
│ │ └── butteraugli_main.cc
│ ├── jpeg.BUILD
│ ├── png.BUILD
│ └── zlib.BUILD
└── tools/
└── guetzli-compare.py
================================================
FILE CONTENTS
================================================
================================================
FILE: .gitignore
================================================
bin/
obj/
/bazel-*
# Visual Studio 2015 cache/options directory
.vs/
# Visual C++ cache files
ipch/
*.aps
*.ncb
*.opendb
*.opensdf
*.sdf
*.cachefile
*.VC.db
*.VC.VC.opendb
================================================
FILE: .travis.sh
================================================
#!/bin/bash
case "$1" in
"install")
case "${TRAVIS_OS_NAME}" in
"linux")
;;
"osx")
brew update
brew install netpbm
;;
esac
case "${BUILD_SYSTEM}" in
"bazel")
case "${TRAVIS_OS_NAME}" in
"linux")
sudo apt-get remove openjdk-9-jdk oracle-java9-installer # Conflicts with Bazel.
wget https://github.com/bazelbuild/bazel/releases/download/1.1.0/bazel_1.1.0-linux-x86_64.deb
echo '138b47ffd54924e3c0264c65d31d3927803fb9025db4d5b18107df79ee3bda95 bazel_1.1.0-linux-x86_64.deb' | sha256sum -c --strict || exit 1
sudo dpkg -i bazel_1.1.0-linux-x86_64.deb
;;
"osx")
brew cask install homebrew/cask-versions/adoptopenjdk8
brew install bazel
;;
esac
;;
"make")
;;
esac
;;
"script")
case "${BUILD_SYSTEM}" in
"bazel")
bazel build -c opt ...:all
GUETZLI_BIN=bazel-bin/guetzli
;;
"make")
make
GUETZLI_BIN=bin/Release/guetzli
;;
esac
tests/smoke_test.sh $GUETZLI_BIN
;;
esac
================================================
FILE: .travis.yml
================================================
language: cpp
sudo: false
matrix:
include:
- os: linux
dist: trusty
sudo: required
env: BUILD_SYSTEM=bazel
addons:
apt:
sources:
- ubuntu-toolchain-r-test
packages:
- libjpeg-progs
- netpbm # For pngtopnm in smoke_test.sh.
- wget
- os: osx
env: BUILD_SYSTEM=bazel
- os: linux
dist: trusty
env: BUILD_SYSTEM=make
addons:
apt:
sources:
- ubuntu-toolchain-r-test
packages:
- libjpeg-progs
- libpng-dev
- netpbm # For pngtopnm in smoke_test.sh.
- pkg-config
- wget
- os: osx
env: BUILD_SYSTEM=make
install:
- ./.travis.sh install
script:
- ./.travis.sh script
================================================
FILE: BUILD
================================================
# Description:
# Bazel build file for Guetzli.
cc_library(
name = "guetzli_lib",
srcs = glob(
[
"guetzli/*.h",
"guetzli/*.cc",
"guetzli/*.inc",
],
exclude = ["guetzli/guetzli.cc"],
),
copts = [ "-Wno-sign-compare" ],
deps = [
"@butteraugli//:butteraugli_lib",
],
)
cc_binary(
name = "guetzli",
srcs = ["guetzli/guetzli.cc"],
deps = [
":guetzli_lib",
"@png_archive//:png",
],
)
================================================
FILE: CONTRIBUTING.md
================================================
Want to contribute bugfixes or non-output-modifying changes (e.g. speedups)?
Great! First, read this page (including the small print at the end). Want to
contribute changes that modify the generated JPEG file? Talk to us first.
### Before you contribute
Before we can use your code, you must sign the
[Google Individual Contributor License Agreement](https://cla.developers.google.com/about/google-individual)
(CLA), which you can do online. The CLA is necessary mainly because you own the
copyright to your changes, even after your contribution becomes part of our
codebase, so we need your permission to use and distribute your code. We also
need to be sure of various other things—for instance that you'll tell us if you
know that your code infringes on other people's patents. You don't have to sign
the CLA until after you've submitted your code for review and a member has
approved it, but you must do it before we can put your code into our codebase.
Before you start working on a larger contribution, you should get in touch with
us first through the issue tracker with your idea so that we can help out and
possibly guide you. Coordinating up front makes it much easier to avoid
frustration later on.
### Code reviews
All submissions, including submissions by project members, require review. We
use Github pull requests for this purpose.
### The small print
Contributions made by corporations are covered by a different agreement than
the one above, the
[Software Grant and Corporate Contributor License Agreement](https://cla.developers.google.com/about/google-corporate).
================================================
FILE: LICENSE
================================================
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright [yyyy] [name of copyright owner]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
================================================
FILE: Makefile
================================================
# GNU Make workspace makefile autogenerated by Premake
ifndef config
config=release
endif
ifndef verbose
SILENT = @
endif
ifeq ($(config),release)
guetzli_static_config = release
guetzli_config = release
endif
ifeq ($(config),debug)
guetzli_static_config = debug
guetzli_config = debug
endif
PROJECTS := guetzli_static guetzli
.PHONY: all clean help $(PROJECTS)
all: $(PROJECTS)
guetzli_static:
ifneq (,$(guetzli_static_config))
@echo "==== Building guetzli_static ($(guetzli_static_config)) ===="
@${MAKE} --no-print-directory -C . -f guetzli_static.make config=$(guetzli_static_config)
endif
guetzli:
ifneq (,$(guetzli_config))
@echo "==== Building guetzli ($(guetzli_config)) ===="
@${MAKE} --no-print-directory -C . -f guetzli.make config=$(guetzli_config)
endif
clean:
@${MAKE} --no-print-directory -C . -f guetzli_static.make clean
@${MAKE} --no-print-directory -C . -f guetzli.make clean
help:
@echo "Usage: make [config=name] [target]"
@echo ""
@echo "CONFIGURATIONS:"
@echo " release"
@echo " debug"
@echo ""
@echo "TARGETS:"
@echo " all (default)"
@echo " clean"
@echo " guetzli_static"
@echo " guetzli"
@echo ""
@echo "For more information, see http://industriousone.com/premake/quick-start"
================================================
FILE: README.md
================================================

# Introduction
Guetzli is a JPEG encoder that aims for excellent compression density at high
visual quality. Guetzli-generated images are typically 20-30% smaller than
images of equivalent quality generated by libjpeg. Guetzli generates only
sequential (nonprogressive) JPEGs due to faster decompression speeds they offer.
[](https://travis-ci.org/google/guetzli)
# Building
## On POSIX systems
1. Get a copy of the source code, either by cloning this repository, or by
downloading an
[archive](https://github.com/google/guetzli/archive/master.zip) and
unpacking it.
2. Install [libpng](http://www.libpng.org/pub/png/libpng.html).
If using your operating system
package manager, install development versions of the packages if the
distinction exists.
* On Ubuntu, do `apt-get install libpng-dev`.
* On Fedora, do `dnf install libpng-devel`.
* On Arch Linux, do `pacman -S libpng`.
* On Alpine Linux, do `apk add libpng-dev`.
3. Run `make` and expect the binary to be created in `bin/Release/guetzli`.
## On Windows
1. Get a copy of the source code, either by cloning this repository, or by
downloading an
[archive](https://github.com/google/guetzli/archive/master.zip) and
unpacking it.
2. Install [Visual Studio 2015](https://www.visualstudio.com) and
[vcpkg](https://github.com/Microsoft/vcpkg)
3. Install `libpng` using vcpkg: `.\vcpkg install libpng`.
4. Cause the installed packages to be available system-wide: `.\vcpkg integrate
install`. If you prefer not to do this, refer to [vcpkg's
documentation](https://github.com/Microsoft/vcpkg/blob/master/docs/EXAMPLES.md#example-1-2).
5. Open the Visual Studio project enclosed in the repository and build it.
## On macOS
To install using [Homebrew](https://brew.sh/):
1. Install [Homebrew](https://brew.sh/)
2. `brew install guetzli`
To install using the repository:
1. Get a copy of the source code, either by cloning this repository, or by
downloading an
[archive](https://github.com/google/guetzli/archive/master.zip) and
unpacking it.
2. Install [Homebrew](https://brew.sh/) or [MacPorts](https://www.macports.org/)
3. Install `libpng`
* Using [Homebrew](https://brew.sh/): `brew install libpng`.
* Using [MacPorts](https://www.macports.org/): `port install libpng` (You may need to use `sudo`).
4. Run the following command to build the binary in `bin/Release/guetzli`.
* If you installed using [Homebrew](https://brew.sh/) simply use `make`
* If you installed using [MacPorts](https://www.macports.org/) use `CFLAGS='-I/opt/local/include' LDFLAGS='-L/opt/local/lib' make`
## With Bazel
There's also a [Bazel](https://bazel.build) build configuration provided. If you
have Bazel installed, you can also compile Guetzli by running `bazel build -c opt //:guetzli`.
# Using
**Note:** Guetzli uses a large amount of memory. You should provide 300MB of
memory per 1MPix of the input image.
**Note:** Guetzli uses a significant amount of CPU time. You should count on
using about 1 minute of CPU per 1 MPix of input image.
**Note:** Guetzli assumes that input is in **sRGB profile** with a **gamma of
2.2**. Guetzli will ignore any color-profile metadata in the image.
To try out Guetzli you need to [build](#building) or
[download](https://github.com/google/guetzli/releases) the Guetzli binary. The
binary reads a PNG or JPEG image and creates an optimized JPEG image:
```bash
guetzli [--quality Q] [--verbose] original.png output.jpg
guetzli [--quality Q] [--verbose] original.jpg output.jpg
```
Note that Guetzli is designed to work on high quality images. You should always
prefer providing uncompressed input images (e.g. that haven't been already
compressed with any JPEG encoders, including Guetzli). While it will work on other
images too, results will be poorer. You can try compressing an enclosed [sample
high quality
image](https://github.com/google/guetzli/releases/download/v0/bees.png).
You can pass a `--quality Q` parameter to set quality in units equivalent to
libjpeg quality. You can also pass a `--verbose` flag to see a trace of encoding
attempts made.
Please note that JPEG images do not support alpha channel (transparency). If the
input is a PNG with an alpha channel, it will be overlaid on black background
before encoding.
================================================
FILE: WORKSPACE
================================================
# Description:
# Bazel workspace file for Guetzli.
workspace(name = "guetzli")
load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
name = "png_archive",
build_file = "png.BUILD",
sha256 = "a941dc09ca00148fe7aaf4ecdd6a67579c293678ed1e1cf633b5ffc02f4f8cf7",
strip_prefix = "libpng-1.2.57",
url = "http://github.com/glennrp/libpng/archive/v1.2.57.zip",
)
http_archive(
name = "zlib_archive",
build_file = "zlib.BUILD",
sha256 = "8d7e9f698ce48787b6e1c67e6bff79e487303e66077e25cb9784ac8835978017",
strip_prefix = "zlib-1.2.10",
url = "http://zlib.net/fossils/zlib-1.2.10.tar.gz",
)
local_repository(
name = "butteraugli",
path = "third_party/butteraugli/",
)
================================================
FILE: appveyor.yml
================================================
version: '1.0.1#{build}'
shallow_clone: true
os:
- Visual Studio 2015
environment:
matrix:
- TOOLSET: vs2015
install:
- ps: Start-FileDownload 'https://github.com/premake/premake-core/releases/download/v5.0.0-alpha11/premake-5.0.0-alpha11-windows.zip' 'premake.zip'
- 7z x premake.zip
- premake5.exe %TOOLSET%
- git clone https://github.com/Microsoft/vcpkg
- md vcpkg\downloads\nuget-3.5.0
- appveyor DownloadFile https://dist.nuget.org/win-x86-commandline/latest/nuget.exe -FileName %appveyor_build_folder%\vcpkg\downloads\nuget-3.5.0\nuget.exe
- appveyor DownloadFile https://cmake.org/files/v3.8/cmake-3.8.0-rc1-win32-x86.zip -FileName %appveyor_build_folder%\vcpkg\downloads\cmake-3.8.0-rc1-win32-x86.zip
- 7z x %appveyor_build_folder%\vcpkg\downloads\cmake-3.8.0-rc1-win32-x86.zip
- cd vcpkg
- powershell -exec bypass -File scripts\bootstrap.ps1
- vcpkg integrate install
- vcpkg install libpng
- cd ..
configuration:
- Debug
- Release
build:
project: guetzli.sln
================================================
FILE: external/png.BUILD
================================================
# Description:
# libpng is the official PNG reference library.
licenses(["notice"]) # BSD/MIT-like license
cc_library(
name = "png",
srcs = [
"png.c",
"pngerror.c",
"pngget.c",
"pngmem.c",
"pngpread.c",
"pngread.c",
"pngrio.c",
"pngrtran.c",
"pngrutil.c",
"pngset.c",
"pngtrans.c",
"pngwio.c",
"pngwrite.c",
"pngwtran.c",
"pngwutil.c",
],
hdrs = [
"png.h",
"pngconf.h",
],
includes = ["."],
linkopts = ["-lm"],
visibility = ["//visibility:public"],
deps = ["@zlib_archive//:zlib"],
)
================================================
FILE: external/zlib.BUILD
================================================
package(default_visibility = ["//visibility:public"])
licenses(["notice"]) # BSD/MIT-like license (for zlib)
cc_library(
name = "zlib",
srcs = [
"adler32.c",
"compress.c",
"crc32.c",
"crc32.h",
"deflate.c",
"deflate.h",
"gzclose.c",
"gzguts.h",
"gzlib.c",
"gzread.c",
"gzwrite.c",
"infback.c",
"inffast.c",
"inffast.h",
"inffixed.h",
"inflate.c",
"inflate.h",
"inftrees.c",
"inftrees.h",
"trees.c",
"trees.h",
"uncompr.c",
"zconf.h",
"zutil.c",
"zutil.h",
],
hdrs = ["zlib.h"],
includes = ["."],
)
================================================
FILE: fuzz_target.cc
================================================
#include
#include "guetzli/jpeg_data.h"
#include "guetzli/jpeg_data_reader.h"
#include "guetzli/processor.h"
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
std::string jpeg_data(reinterpret_cast(data), size);
// Ignore large images, to prevent timeouts.
guetzli::JPEGData jpg_header;
if (!guetzli::ReadJpeg(data, size, guetzli::JPEG_READ_HEADER, &jpg_header)) {
return 0;
}
static constexpr int kMaxPixels = 10000;
if (static_cast(jpg_header.width) * jpg_header.height > kMaxPixels) {
return 0;
}
// TODO(robryk): Use nondefault parameters.
guetzli::Params params;
std::string jpeg_out;
(void)guetzli::Process(params, nullptr, jpeg_data, &jpeg_out);
// TODO(robryk): Verify output distance if Process() succeeded.
return 0;
}
================================================
FILE: guetzli/butteraugli_comparator.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/butteraugli_comparator.h"
#include
#include "guetzli/debug_print.h"
#include "guetzli/gamma_correct.h"
#include "guetzli/score.h"
namespace guetzli {
namespace {
using ::butteraugli::ImageF;
using ::butteraugli::CreatePlanes;
using ::butteraugli::PlanesFromPacked;
using ::butteraugli::PackedFromPlanes;
std::vector LinearRgb(const size_t xsize, const size_t ysize,
const std::vector& rgb) {
const double* lut = Srgb8ToLinearTable();
std::vector planes = CreatePlanes(xsize, ysize, 3);
for (int c = 0; c < 3; ++c) {
for (size_t y = 0; y < ysize; ++y) {
const uint8_t* const BUTTERAUGLI_RESTRICT row_in = &rgb[3 * xsize * y];
float* const BUTTERAUGLI_RESTRICT row_out = planes[c].Row(y);
for (size_t x = 0; x < xsize; ++x) {
row_out[x] = lut[row_in[3 * x + c]];
}
}
}
return planes;
}
} // namespace
ButteraugliComparator::ButteraugliComparator(const int width, const int height,
const std::vector* rgb,
const float target_distance,
ProcessStats* stats)
: width_(width),
height_(height),
target_distance_(target_distance),
rgb_orig_(*rgb),
comparator_(LinearRgb(width_, height_, *rgb)),
distance_(0.0),
stats_(stats) {}
void ButteraugliComparator::Compare(const OutputImage& img) {
std::vector rgb0 =
::butteraugli::OpsinDynamicsImage(LinearRgb(width_, height_, rgb_orig_));
std::vector > rgb(3, std::vector(width_ * height_));
img.ToLinearRGB(&rgb);
const std::vector rgb_planes = PlanesFromPacked(width_, height_, rgb);
std::vector(width_ * height_).swap(distmap_);
ImageF distmap;
comparator_.Diffmap(rgb_planes, distmap);
CopyToPacked(distmap, &distmap_);
distance_ = ::butteraugli::ButteraugliScoreFromDiffmap(distmap);
GUETZLI_LOG(stats_, " BA[100.00%%] D[%6.4f]", distance_);
}
namespace {
// To change this to n, add the relevant FFTn function and kFFTnMapIndexTable.
constexpr size_t kBlockEdge = 8;
constexpr size_t kBlockSize = kBlockEdge * kBlockEdge;
constexpr size_t kBlockEdgeHalf = kBlockEdge / 2;
constexpr size_t kBlockHalf = kBlockEdge * kBlockEdgeHalf;
// Contrast sensitivity related weights.
// Contrast sensitivity matrix is a model of the contrast sensitivity of the
// human eye. The contrast sensitivity function, also known as contrast
// sensitivity curve, is a basic psychovisual function and it roughly means
// that highest frequences have less impact than middle and low frequences.
//
// The order of coefficients here is slightly confusing.
// It is a creative order that benefits from the mirroring of the fft.
static const double *GetContrastSensitivityMatrix() {
static double csf8x8[kBlockHalf + kBlockEdgeHalf + 1] = {
0.0, // no 8x8 dc, enough 'dc' is calculated from low/mid freq images.
0.0,
0.0,
0.0,
0.3831134973,
0.676303603859,
1.1550451483,
8,
8,
0.692062533689,
0.847511538605,
0.498250875965,
0.36198671102,
0.308982169883,
0.1312701920435,
4.71274312228,
1.1550451483,
0.847511538605,
4.71274312228,
0.991205724152,
1.30229591239,
0.627264168628,
0.4,
0.1312701920435,
0.676303603859,
0.498250875965,
0.991205724152,
0.5,
0.3831134973,
0.349686450518,
0.627264168628,
0.308982169883,
0.3831134973,
0.36198671102,
1.30229591239,
0.3831134973,
0.323078800177,
};
return &csf8x8[0];
}
struct Complex {
double real;
double imag;
};
inline double abssq(const Complex& c) {
return c.real * c.real + c.imag * c.imag;
}
static void TransposeBlock(Complex data[kBlockSize]) {
for (int i = 0; i < kBlockEdge; i++) {
for (int j = 0; j < i; j++) {
std::swap(data[kBlockEdge * i + j], data[kBlockEdge * j + i]);
}
}
}
// D. J. Bernstein's Fast Fourier Transform algorithm on 4 elements.
inline void FFT4(Complex* a) {
double t1, t2, t3, t4, t5, t6, t7, t8;
t5 = a[2].real;
t1 = a[0].real - t5;
t7 = a[3].real;
t5 += a[0].real;
t3 = a[1].real - t7;
t7 += a[1].real;
t8 = t5 + t7;
a[0].real = t8;
t5 -= t7;
a[1].real = t5;
t6 = a[2].imag;
t2 = a[0].imag - t6;
t6 += a[0].imag;
t5 = a[3].imag;
a[2].imag = t2 + t3;
t2 -= t3;
a[3].imag = t2;
t4 = a[1].imag - t5;
a[3].real = t1 + t4;
t1 -= t4;
a[2].real = t1;
t5 += a[1].imag;
a[0].imag = t6 + t5;
t6 -= t5;
a[1].imag = t6;
}
const double kSqrtHalf = 0.70710678118654752440084436210484903;
// D. J. Bernstein's Fast Fourier Transform algorithm on 8 elements.
void FFT8(Complex* a) {
double t1, t2, t3, t4, t5, t6, t7, t8;
t7 = a[4].imag;
t4 = a[0].imag - t7;
t7 += a[0].imag;
a[0].imag = t7;
t8 = a[6].real;
t5 = a[2].real - t8;
t8 += a[2].real;
a[2].real = t8;
t7 = a[6].imag;
a[6].imag = t4 - t5;
t4 += t5;
a[4].imag = t4;
t6 = a[2].imag - t7;
t7 += a[2].imag;
a[2].imag = t7;
t8 = a[4].real;
t3 = a[0].real - t8;
t8 += a[0].real;
a[0].real = t8;
a[4].real = t3 - t6;
t3 += t6;
a[6].real = t3;
t7 = a[5].real;
t3 = a[1].real - t7;
t7 += a[1].real;
a[1].real = t7;
t8 = a[7].imag;
t6 = a[3].imag - t8;
t8 += a[3].imag;
a[3].imag = t8;
t1 = t3 - t6;
t3 += t6;
t7 = a[5].imag;
t4 = a[1].imag - t7;
t7 += a[1].imag;
a[1].imag = t7;
t8 = a[7].real;
t5 = a[3].real - t8;
t8 += a[3].real;
a[3].real = t8;
t2 = t4 - t5;
t4 += t5;
t6 = t1 - t4;
t8 = kSqrtHalf;
t6 *= t8;
a[5].real = a[4].real - t6;
t1 += t4;
t1 *= t8;
a[5].imag = a[4].imag - t1;
t6 += a[4].real;
a[4].real = t6;
t1 += a[4].imag;
a[4].imag = t1;
t5 = t2 - t3;
t5 *= t8;
a[7].imag = a[6].imag - t5;
t2 += t3;
t2 *= t8;
a[7].real = a[6].real - t2;
t2 += a[6].real;
a[6].real = t2;
t5 += a[6].imag;
a[6].imag = t5;
FFT4(a);
// Reorder to the correct output order.
// TODO(szabadka): Modify the above computation so that this is not needed.
Complex tmp = a[2];
a[2] = a[3];
a[3] = a[5];
a[5] = a[7];
a[7] = a[4];
a[4] = a[1];
a[1] = a[6];
a[6] = tmp;
}
// Same as FFT8, but all inputs are real.
// TODO(szabadka): Since this does not need to be in-place, maybe there is a
// faster FFT than this one, which is derived from DJB's in-place complex FFT.
void RealFFT8(const double* in, Complex* out) {
double t1, t2, t3, t5, t6, t7, t8;
t8 = in[6];
t5 = in[2] - t8;
t8 += in[2];
out[2].real = t8;
out[6].imag = -t5;
out[4].imag = t5;
t8 = in[4];
t3 = in[0] - t8;
t8 += in[0];
out[0].real = t8;
out[4].real = t3;
out[6].real = t3;
t7 = in[5];
t3 = in[1] - t7;
t7 += in[1];
out[1].real = t7;
t8 = in[7];
t5 = in[3] - t8;
t8 += in[3];
out[3].real = t8;
t2 = -t5;
t6 = t3 - t5;
t8 = kSqrtHalf;
t6 *= t8;
out[5].real = out[4].real - t6;
t1 = t3 + t5;
t1 *= t8;
out[5].imag = out[4].imag - t1;
t6 += out[4].real;
out[4].real = t6;
t1 += out[4].imag;
out[4].imag = t1;
t5 = t2 - t3;
t5 *= t8;
out[7].imag = out[6].imag - t5;
t2 += t3;
t2 *= t8;
out[7].real = out[6].real - t2;
t2 += out[6].real;
out[6].real = t2;
t5 += out[6].imag;
out[6].imag = t5;
t5 = out[2].real;
t1 = out[0].real - t5;
t7 = out[3].real;
t5 += out[0].real;
t3 = out[1].real - t7;
t7 += out[1].real;
t8 = t5 + t7;
out[0].real = t8;
t5 -= t7;
out[1].real = t5;
out[2].imag = t3;
out[3].imag = -t3;
out[3].real = t1;
out[2].real = t1;
out[0].imag = 0;
out[1].imag = 0;
// Reorder to the correct output order.
// TODO(szabadka): Modify the above computation so that this is not needed.
Complex tmp = out[2];
out[2] = out[3];
out[3] = out[5];
out[5] = out[7];
out[7] = out[4];
out[4] = out[1];
out[1] = out[6];
out[6] = tmp;
}
// Fills in block[kBlockEdgeHalf..(kBlockHalf+kBlockEdgeHalf)], and leaves the
// rest unmodified.
void ButteraugliFFTSquared(double block[kBlockSize]) {
double global_mul = 0.000064;
Complex block_c[kBlockSize];
assert(kBlockEdge == 8);
for (int y = 0; y < kBlockEdge; ++y) {
RealFFT8(block + y * kBlockEdge, block_c + y * kBlockEdge);
}
TransposeBlock(block_c);
double r0[kBlockEdge];
double r1[kBlockEdge];
for (int x = 0; x < kBlockEdge; ++x) {
r0[x] = block_c[x].real;
r1[x] = block_c[kBlockHalf + x].real;
}
RealFFT8(r0, block_c);
RealFFT8(r1, block_c + kBlockHalf);
for (int y = 1; y < kBlockEdgeHalf; ++y) {
FFT8(block_c + y * kBlockEdge);
}
for (int i = kBlockEdgeHalf; i < kBlockHalf + kBlockEdgeHalf + 1; ++i) {
block[i] = abssq(block_c[i]);
block[i] *= global_mul;
}
}
void ButteraugliBlockDiff(double xyb0[3 * kBlockSize],
double xyb1[3 * kBlockSize],
double* diff_xyb) {
const double *csf8x8 = GetContrastSensitivityMatrix();
double avgdiff_xyb[3] = {0.0};
for (int i = 0; i < 3 * kBlockSize; ++i) {
avgdiff_xyb[i / kBlockSize] += xyb0[i] - xyb1[i];
}
for (int c = 0; c < 3; ++c) {
double avgdiff = avgdiff_xyb[c] / kBlockSize;
diff_xyb[c] += 4.0 * avgdiff * avgdiff;
}
double x_diff[kBlockSize];
double y_diff[kBlockSize];
double b_diff[kBlockSize];
for (int i = 0; i < kBlockSize; ++i) {
x_diff[i] = (xyb0[i] - xyb1[i]);
y_diff[i] = (xyb0[kBlockSize + i] - xyb1[kBlockSize + i]);
b_diff[i] = (xyb0[2 * kBlockSize + i] - xyb1[2 * kBlockSize + i]);
}
ButteraugliFFTSquared(x_diff);
ButteraugliFFTSquared(y_diff);
ButteraugliFFTSquared(b_diff);
for (size_t i = kBlockEdgeHalf; i < kBlockHalf + kBlockEdgeHalf + 1; ++i) {
double d = csf8x8[i];
diff_xyb[0] += d * x_diff[i];
diff_xyb[1] += d * y_diff[i];
diff_xyb[2] += d * b_diff[i];
}
}
} // namespace
void ButteraugliComparator::StartBlockComparisons() {
std::vector dummy(3);
std::vector rgb0 =
::butteraugli::OpsinDynamicsImage(LinearRgb(width_, height_, rgb_orig_));
::butteraugli::Mask(rgb0, rgb0,
&mask_xyz_, &dummy);
}
void ButteraugliComparator::FinishBlockComparisons() {
mask_xyz_.clear();
}
void ButteraugliComparator::SwitchBlock(int block_x, int block_y,
int factor_x, int factor_y) {
block_x_ = block_x;
block_y_ = block_y;
factor_x_ = factor_x;
factor_y_ = factor_y;
per_block_pregamma_.resize(factor_x_ * factor_y_);
const double* lut = Srgb8ToLinearTable();
for (int off_y = 0, bx = 0; off_y < factor_y_; ++off_y) {
for (int off_x = 0; off_x < factor_x_; ++off_x, ++bx) {
per_block_pregamma_[bx].resize(3, std::vector(kDCTBlockSize));
int block_xx = block_x_ * factor_x_ + off_x;
int block_yy = block_y_ * factor_y_ + off_y;
for (int iy = 0, i = 0; iy < 8; ++iy) {
for (int ix = 0; ix < 8; ++ix, ++i) {
int x = std::min(8 * block_xx + ix, width_ - 1);
int y = std::min(8 * block_yy + iy, height_ - 1);
int px = y * width_ + x;
for (int c = 0; c < 3; ++c) {
per_block_pregamma_[bx][c][i] = lut[rgb_orig_[3 * px + c]];
}
}
}
per_block_pregamma_[bx] =
::butteraugli::PackedFromPlanes(::butteraugli::OpsinDynamicsImage(
::butteraugli::PlanesFromPacked(8, 8, per_block_pregamma_[bx])));
}
}
}
double ButteraugliComparator::CompareBlock(const OutputImage& img,
int off_x, int off_y) const {
int block_x = block_x_ * factor_x_ + off_x;
int block_y = block_y_ * factor_y_ + off_y;
int xmin = 8 * block_x;
int ymin = 8 * block_y;
int block_ix = off_y * factor_x_ + off_x;
const std::vector >& rgb0 =
per_block_pregamma_[block_ix];
std::vector > rgb1(3, std::vector(kDCTBlockSize));
img.ToLinearRGB(xmin, ymin, 8, 8, &rgb1);
rgb1 = ::butteraugli::PackedFromPlanes(::butteraugli::OpsinDynamicsImage(
::butteraugli::PlanesFromPacked(8, 8, rgb1)));
double b0[3 * kDCTBlockSize];
double b1[3 * kDCTBlockSize];
for (int c = 0; c < 3; ++c) {
for (int ix = 0; ix < kDCTBlockSize; ++ix) {
b0[c * kDCTBlockSize + ix] = rgb0[c][ix];
b1[c * kDCTBlockSize + ix] = rgb1[c][ix];
}
}
double diff_xyz[3] = { 0.0 };
ButteraugliBlockDiff(b0, b1, diff_xyz);
double diff = 0.0;
for (int c = 0; c < 3; ++c) {
diff += diff_xyz[c] * mask_xyz_[c].Row(ymin)[xmin];
}
return sqrt(diff);
}
float ButteraugliComparator::BlockErrorLimit() const {
return target_distance_;
}
void ButteraugliComparator::ComputeBlockErrorAdjustmentWeights(
int direction,
int max_block_dist,
double target_mul,
int factor_x, int factor_y,
const std::vector& distmap,
std::vector* block_weight) {
const double target_distance = target_distance_ * target_mul;
const int sizex = 8 * factor_x;
const int sizey = 8 * factor_y;
const int block_width = (width_ + sizex - 1) / sizex;
const int block_height = (height_ + sizey - 1) / sizey;
std::vector max_dist_per_block(block_width * block_height);
for (int block_y = 0; block_y < block_height; ++block_y) {
for (int block_x = 0; block_x < block_width; ++block_x) {
int block_ix = block_y * block_width + block_x;
int x_max = std::min(width_, sizex * (block_x + 1));
int y_max = std::min(height_, sizey * (block_y + 1));
float max_dist = 0.0;
for (int y = sizey * block_y; y < y_max; ++y) {
for (int x = sizex * block_x; x < x_max; ++x) {
max_dist = std::max(max_dist, distmap[y * width_ + x]);
}
}
max_dist_per_block[block_ix] = max_dist;
}
}
for (int block_y = 0; block_y < block_height; ++block_y) {
for (int block_x = 0; block_x < block_width; ++block_x) {
int block_ix = block_y * block_width + block_x;
float max_local_dist = static_cast(target_distance);
int x_min = std::max(0, block_x - max_block_dist);
int y_min = std::max(0, block_y - max_block_dist);
int x_max = std::min(block_width, block_x + 1 + max_block_dist);
int y_max = std::min(block_height, block_y + 1 + max_block_dist);
for (int y = y_min; y < y_max; ++y) {
for (int x = x_min; x < x_max; ++x) {
max_local_dist =
std::max(max_local_dist, max_dist_per_block[y * block_width + x]);
}
}
if (direction > 0) {
if (max_dist_per_block[block_ix] <= target_distance &&
max_local_dist <= 1.1 * target_distance) {
(*block_weight)[block_ix] = 1.0;
}
} else {
constexpr double kLocalMaxWeight = 0.5;
if (max_dist_per_block[block_ix] <=
(1 - kLocalMaxWeight) * target_distance +
kLocalMaxWeight * max_local_dist) {
continue;
}
for (int y = y_min; y < y_max; ++y) {
for (int x = x_min; x < x_max; ++x) {
int d = std::max(std::abs(y - block_y), std::abs(x - block_x));
int ix = y * block_width + x;
(*block_weight)[ix] = std::max(
(*block_weight)[ix], 1.0f / (d + 1.0f));
}
}
}
}
}
}
double ButteraugliComparator::ScoreOutputSize(int size) const {
return ScoreJPEG(distance_, size, target_distance_);
}
} // namespace guetzli
================================================
FILE: guetzli/butteraugli_comparator.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_BUTTERAUGLI_COMPARATOR_H_
#define GUETZLI_BUTTERAUGLI_COMPARATOR_H_
#include
#include "butteraugli/butteraugli.h"
#include "guetzli/comparator.h"
#include "guetzli/jpeg_data.h"
#include "guetzli/output_image.h"
#include "guetzli/stats.h"
namespace guetzli {
constexpr int kButteraugliStep = 3;
class ButteraugliComparator : public Comparator {
public:
ButteraugliComparator(const int width, const int height,
const std::vector* rgb,
const float target_distance, ProcessStats* stats);
void Compare(const OutputImage& img) override;
void StartBlockComparisons() override;
void FinishBlockComparisons() override;
void SwitchBlock(int block_x, int block_y,
int factor_x, int factor_y) override;
double CompareBlock(const OutputImage& img,
int off_x, int off_y) const override;
double ScoreOutputSize(int size) const override;
bool DistanceOK(double target_mul) const override {
return distance_ <= target_mul * target_distance_;
}
const std::vector distmap() const override { return distmap_; }
float distmap_aggregate() const override { return distance_; }
float BlockErrorLimit() const override;
void ComputeBlockErrorAdjustmentWeights(
int direction, int max_block_dist, double target_mul, int factor_x,
int factor_y, const std::vector& distmap,
std::vector* block_weight) override;
private:
const int width_;
const int height_;
const float target_distance_;
const std::vector& rgb_orig_;
int block_x_;
int block_y_;
int factor_x_;
int factor_y_;
std::vector<::butteraugli::ImageF> mask_xyz_;
std::vector>> per_block_pregamma_;
::butteraugli::ButteraugliComparator comparator_;
float distance_;
std::vector distmap_;
ProcessStats* stats_;
};
} // namespace guetzli
#endif // GUETZLI_BUTTERAUGLI_COMPARATOR_H_
================================================
FILE: guetzli/color_transform.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_COLOR_TRANSFORM_H_
#define GUETZLI_COLOR_TRANSFORM_H_
namespace guetzli {
static const int kCrToRedTable[256] = {
-179, -178, -177, -175, -174, -172, -171, -170, -168, -167, -165, -164,
-163, -161, -160, -158, -157, -156, -154, -153, -151, -150, -149, -147,
-146, -144, -143, -142, -140, -139, -137, -136, -135, -133, -132, -130,
-129, -128, -126, -125, -123, -122, -121, -119, -118, -116, -115, -114,
-112, -111, -109, -108, -107, -105, -104, -102, -101, -100, -98, -97,
-95, -94, -93, -91, -90, -88, -87, -86, -84, -83, -81, -80,
-79, -77, -76, -74, -73, -72, -70, -69, -67, -66, -64, -63,
-62, -60, -59, -57, -56, -55, -53, -52, -50, -49, -48, -46,
-45, -43, -42, -41, -39, -38, -36, -35, -34, -32, -31, -29,
-28, -27, -25, -24, -22, -21, -20, -18, -17, -15, -14, -13,
-11, -10, -8, -7, -6, -4, -3, -1, 0, 1, 3, 4,
6, 7, 8, 10, 11, 13, 14, 15, 17, 18, 20, 21,
22, 24, 25, 27, 28, 29, 31, 32, 34, 35, 36, 38,
39, 41, 42, 43, 45, 46, 48, 49, 50, 52, 53, 55,
56, 57, 59, 60, 62, 63, 64, 66, 67, 69, 70, 72,
73, 74, 76, 77, 79, 80, 81, 83, 84, 86, 87, 88,
90, 91, 93, 94, 95, 97, 98, 100, 101, 102, 104, 105,
107, 108, 109, 111, 112, 114, 115, 116, 118, 119, 121, 122,
123, 125, 126, 128, 129, 130, 132, 133, 135, 136, 137, 139,
140, 142, 143, 144, 146, 147, 149, 150, 151, 153, 154, 156,
157, 158, 160, 161, 163, 164, 165, 167, 168, 170, 171, 172,
174, 175, 177, 178
};
static const int kCbToBlueTable[256] = {
-227, -225, -223, -222, -220, -218, -216, -214, -213, -211, -209, -207,
-206, -204, -202, -200, -198, -197, -195, -193, -191, -190, -188, -186,
-184, -183, -181, -179, -177, -175, -174, -172, -170, -168, -167, -165,
-163, -161, -159, -158, -156, -154, -152, -151, -149, -147, -145, -144,
-142, -140, -138, -136, -135, -133, -131, -129, -128, -126, -124, -122,
-120, -119, -117, -115, -113, -112, -110, -108, -106, -105, -103, -101,
-99, -97, -96, -94, -92, -90, -89, -87, -85, -83, -82, -80,
-78, -76, -74, -73, -71, -69, -67, -66, -64, -62, -60, -58,
-57, -55, -53, -51, -50, -48, -46, -44, -43, -41, -39, -37,
-35, -34, -32, -30, -28, -27, -25, -23, -21, -19, -18, -16,
-14, -12, -11, -9, -7, -5, -4, -2, 0, 2, 4, 5,
7, 9, 11, 12, 14, 16, 18, 19, 21, 23, 25, 27,
28, 30, 32, 34, 35, 37, 39, 41, 43, 44, 46, 48,
50, 51, 53, 55, 57, 58, 60, 62, 64, 66, 67, 69,
71, 73, 74, 76, 78, 80, 82, 83, 85, 87, 89, 90,
92, 94, 96, 97, 99, 101, 103, 105, 106, 108, 110, 112,
113, 115, 117, 119, 120, 122, 124, 126, 128, 129, 131, 133,
135, 136, 138, 140, 142, 144, 145, 147, 149, 151, 152, 154,
156, 158, 159, 161, 163, 165, 167, 168, 170, 172, 174, 175,
177, 179, 181, 183, 184, 186, 188, 190, 191, 193, 195, 197,
198, 200, 202, 204, 206, 207, 209, 211, 213, 214, 216, 218,
220, 222, 223, 225,
};
static const int kCrToGreenTable[256] = {
5990656, 5943854, 5897052, 5850250, 5803448, 5756646, 5709844, 5663042,
5616240, 5569438, 5522636, 5475834, 5429032, 5382230, 5335428, 5288626,
5241824, 5195022, 5148220, 5101418, 5054616, 5007814, 4961012, 4914210,
4867408, 4820606, 4773804, 4727002, 4680200, 4633398, 4586596, 4539794,
4492992, 4446190, 4399388, 4352586, 4305784, 4258982, 4212180, 4165378,
4118576, 4071774, 4024972, 3978170, 3931368, 3884566, 3837764, 3790962,
3744160, 3697358, 3650556, 3603754, 3556952, 3510150, 3463348, 3416546,
3369744, 3322942, 3276140, 3229338, 3182536, 3135734, 3088932, 3042130,
2995328, 2948526, 2901724, 2854922, 2808120, 2761318, 2714516, 2667714,
2620912, 2574110, 2527308, 2480506, 2433704, 2386902, 2340100, 2293298,
2246496, 2199694, 2152892, 2106090, 2059288, 2012486, 1965684, 1918882,
1872080, 1825278, 1778476, 1731674, 1684872, 1638070, 1591268, 1544466,
1497664, 1450862, 1404060, 1357258, 1310456, 1263654, 1216852, 1170050,
1123248, 1076446, 1029644, 982842, 936040, 889238, 842436, 795634,
748832, 702030, 655228, 608426, 561624, 514822, 468020, 421218,
374416, 327614, 280812, 234010, 187208, 140406, 93604, 46802,
0, -46802, -93604, -140406, -187208, -234010, -280812, -327614,
-374416, -421218, -468020, -514822, -561624, -608426, -655228, -702030,
-748832, -795634, -842436, -889238, -936040, -982842, -1029644, -1076446,
-1123248, -1170050, -1216852, -1263654, -1310456, -1357258, -1404060, -1450862,
-1497664, -1544466, -1591268, -1638070, -1684872, -1731674, -1778476, -1825278,
-1872080, -1918882, -1965684, -2012486, -2059288, -2106090, -2152892, -2199694,
-2246496, -2293298, -2340100, -2386902, -2433704, -2480506, -2527308, -2574110,
-2620912, -2667714, -2714516, -2761318, -2808120, -2854922, -2901724, -2948526,
-2995328, -3042130, -3088932, -3135734, -3182536, -3229338, -3276140, -3322942,
-3369744, -3416546, -3463348, -3510150, -3556952, -3603754, -3650556, -3697358,
-3744160, -3790962, -3837764, -3884566, -3931368, -3978170, -4024972, -4071774,
-4118576, -4165378, -4212180, -4258982, -4305784, -4352586, -4399388, -4446190,
-4492992, -4539794, -4586596, -4633398, -4680200, -4727002, -4773804, -4820606,
-4867408, -4914210, -4961012, -5007814, -5054616, -5101418, -5148220, -5195022,
-5241824, -5288626, -5335428, -5382230, -5429032, -5475834, -5522636, -5569438,
-5616240, -5663042, -5709844, -5756646, -5803448, -5850250, -5897052, -5943854,
};
static const int kCbToGreenTable[256] = {
2919680, 2897126, 2874572, 2852018, 2829464, 2806910, 2784356, 2761802,
2739248, 2716694, 2694140, 2671586, 2649032, 2626478, 2603924, 2581370,
2558816, 2536262, 2513708, 2491154, 2468600, 2446046, 2423492, 2400938,
2378384, 2355830, 2333276, 2310722, 2288168, 2265614, 2243060, 2220506,
2197952, 2175398, 2152844, 2130290, 2107736, 2085182, 2062628, 2040074,
2017520, 1994966, 1972412, 1949858, 1927304, 1904750, 1882196, 1859642,
1837088, 1814534, 1791980, 1769426, 1746872, 1724318, 1701764, 1679210,
1656656, 1634102, 1611548, 1588994, 1566440, 1543886, 1521332, 1498778,
1476224, 1453670, 1431116, 1408562, 1386008, 1363454, 1340900, 1318346,
1295792, 1273238, 1250684, 1228130, 1205576, 1183022, 1160468, 1137914,
1115360, 1092806, 1070252, 1047698, 1025144, 1002590, 980036, 957482,
934928, 912374, 889820, 867266, 844712, 822158, 799604, 777050,
754496, 731942, 709388, 686834, 664280, 641726, 619172, 596618,
574064, 551510, 528956, 506402, 483848, 461294, 438740, 416186,
393632, 371078, 348524, 325970, 303416, 280862, 258308, 235754,
213200, 190646, 168092, 145538, 122984, 100430, 77876, 55322,
32768, 10214, -12340, -34894, -57448, -80002, -102556, -125110,
-147664, -170218, -192772, -215326, -237880, -260434, -282988, -305542,
-328096, -350650, -373204, -395758, -418312, -440866, -463420, -485974,
-508528, -531082, -553636, -576190, -598744, -621298, -643852, -666406,
-688960, -711514, -734068, -756622, -779176, -801730, -824284, -846838,
-869392, -891946, -914500, -937054, -959608, -982162, -1004716, -1027270,
-1049824, -1072378, -1094932, -1117486, -1140040, -1162594, -1185148, -1207702,
-1230256, -1252810, -1275364, -1297918, -1320472, -1343026, -1365580, -1388134,
-1410688, -1433242, -1455796, -1478350, -1500904, -1523458, -1546012, -1568566,
-1591120, -1613674, -1636228, -1658782, -1681336, -1703890, -1726444, -1748998,
-1771552, -1794106, -1816660, -1839214, -1861768, -1884322, -1906876, -1929430,
-1951984, -1974538, -1997092, -2019646, -2042200, -2064754, -2087308, -2109862,
-2132416, -2154970, -2177524, -2200078, -2222632, -2245186, -2267740, -2290294,
-2312848, -2335402, -2357956, -2380510, -2403064, -2425618, -2448172, -2470726,
-2493280, -2515834, -2538388, -2560942, -2583496, -2606050, -2628604, -2651158,
-2673712, -2696266, -2718820, -2741374, -2763928, -2786482, -2809036, -2831590,
};
static const uint8_t kRangeLimitLut[4 * 256] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
};
static const uint8_t* kRangeLimit = kRangeLimitLut + 384;
inline void ColorTransformYCbCrToRGB(uint8_t* pixel) {
int y = pixel[0];
int cb = pixel[1];
int cr = pixel[2];
pixel[0] = kRangeLimit[y + kCrToRedTable[cr]];
pixel[1] = kRangeLimit[y +
((kCrToGreenTable[cr] + kCbToGreenTable[cb]) >> 16)];
pixel[2] = kRangeLimit[y + kCbToBlueTable[cb]];
}
} // namespace guetzli
#endif // GUETZLI_COLOR_TRANSFORM_H_
================================================
FILE: guetzli/comparator.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_COMPARATOR_H_
#define GUETZLI_COMPARATOR_H_
#include
#include "guetzli/output_image.h"
#include "guetzli/stats.h"
namespace guetzli {
// Represents a baseline image, a comparison metric and an image acceptance
// criteria based on this metric.
class Comparator {
public:
Comparator() {}
virtual ~Comparator() {}
// Compares img with the baseline image and saves the resulting distance map
// inside the object. The provided image must have the same dimensions as the
// baseline image.
virtual void Compare(const OutputImage& img) = 0;
// Must be called before any CompareBlock() calls can be called.
virtual void StartBlockComparisons() = 0;
// No more CompareBlock() calls can be called after this.
virtual void FinishBlockComparisons() = 0;
// Sets the coordinates of the current macro-block for the purpose of
// CompareBlock() calls.
virtual void SwitchBlock(int block_x, int block_y,
int factor_x, int factor_y) = 0;
// Compares the 8x8 block with offsets (off_x, off_y) within the current
// macro-block of the baseline image with the same block of img and returns
// the resulting per-block distance. The interpretation of the returned
// distance depends on the comparator used.
virtual double CompareBlock(const OutputImage& img,
int off_x, int off_y) const = 0;
// Returns the combined score of the output image in the last Compare() call
// (or the baseline image, if Compare() was not called yet), based on output
// size and the similarity metric.
virtual double ScoreOutputSize(int size) const = 0;
// Returns true if the argument of the last Compare() call (or the baseline
// image, if Compare() was not called yet) meets the image acceptance
// criteria. The target_mul modifies the acceptance criteria used in this call
// the following way:
// = 1.0 : the original acceptance criteria is used,
// < 1.0 : a more strict acceptance criteria is used,
// > 1.0 : a less strict acceptance criteria is used.
virtual bool DistanceOK(double target_mul) const = 0;
// Returns the distance map between the baseline image and the image in the
// last Compare() call (or the baseline image, if Compare() was not called
// yet).
// The dimensions of the distance map are the same as the baseline image.
// The interpretation of the distance values depend on the comparator used.
virtual const std::vector distmap() const = 0;
// Returns an aggregate distance or similarity value between the baseline
// image and the image in the last Compare() call (or the baseline image, if
// Compare() was not called yet).
// The interpretation of this aggregate value depends on the comparator used.
virtual float distmap_aggregate() const = 0;
// Returns a heuristic cutoff on block errors in the sense that we won't
// consider distortions where a block error is greater than this.
virtual float BlockErrorLimit() const = 0;
// Given the search direction (+1 for upwards and -1 for downwards) and the
// current distance map, fills in *block_weight image with the relative block
// error adjustment weights.
// The target_mul param has the same semantics as in DistanceOK().
// Note that this is essentially a static function in the sense that it does
// not depend on the last Compare() call.
virtual void ComputeBlockErrorAdjustmentWeights(
int direction, int max_block_dist, double target_mul, int factor_x,
int factor_y, const std::vector& distmap,
std::vector* block_weight) = 0;
};
} // namespace guetzli
#endif // GUETZLI_COMPARATOR_H_
================================================
FILE: guetzli/dct_double.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/dct_double.h"
#include
#include
namespace guetzli {
namespace {
// kDCTMatrix[8*u+x] = 0.5*alpha(u)*cos((2*x+1)*u*M_PI/16),
// where alpha(0) = 1/sqrt(2) and alpha(u) = 1 for u > 0.
static const double kDCTMatrix[64] = {
0.3535533906, 0.3535533906, 0.3535533906, 0.3535533906,
0.3535533906, 0.3535533906, 0.3535533906, 0.3535533906,
0.4903926402, 0.4157348062, 0.2777851165, 0.0975451610,
-0.0975451610, -0.2777851165, -0.4157348062, -0.4903926402,
0.4619397663, 0.1913417162, -0.1913417162, -0.4619397663,
-0.4619397663, -0.1913417162, 0.1913417162, 0.4619397663,
0.4157348062, -0.0975451610, -0.4903926402, -0.2777851165,
0.2777851165, 0.4903926402, 0.0975451610, -0.4157348062,
0.3535533906, -0.3535533906, -0.3535533906, 0.3535533906,
0.3535533906, -0.3535533906, -0.3535533906, 0.3535533906,
0.2777851165, -0.4903926402, 0.0975451610, 0.4157348062,
-0.4157348062, -0.0975451610, 0.4903926402, -0.2777851165,
0.1913417162, -0.4619397663, 0.4619397663, -0.1913417162,
-0.1913417162, 0.4619397663, -0.4619397663, 0.1913417162,
0.0975451610, -0.2777851165, 0.4157348062, -0.4903926402,
0.4903926402, -0.4157348062, 0.2777851165, -0.0975451610,
};
void DCT1d(const double* in, int stride, double* out) {
for (int x = 0; x < 8; ++x) {
out[x * stride] = 0.0;
for (int u = 0; u < 8; ++u) {
out[x * stride] += kDCTMatrix[8 * x + u] * in[u * stride];
}
}
}
void IDCT1d(const double* in, int stride, double* out) {
for (int x = 0; x < 8; ++x) {
out[x * stride] = 0.0;
for (int u = 0; u < 8; ++u) {
out[x * stride] += kDCTMatrix[8 * u + x] * in[u * stride];
}
}
}
typedef void (*Transform1d)(const double* in, int stride, double* out);
void TransformBlock(double block[64], Transform1d f) {
double tmp[64];
for (int x = 0; x < 8; ++x) {
f(&block[x], 8, &tmp[x]);
}
for (int y = 0; y < 8; ++y) {
f(&tmp[8 * y], 1, &block[8 * y]);
}
}
} // namespace
void ComputeBlockDCTDouble(double block[64]) {
TransformBlock(block, DCT1d);
}
void ComputeBlockIDCTDouble(double block[64]) {
TransformBlock(block, IDCT1d);
}
} // namespace guetzli
================================================
FILE: guetzli/dct_double.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_DCT_DOUBLE_H_
#define GUETZLI_DCT_DOUBLE_H_
namespace guetzli {
// Performs in-place floating point 8x8 DCT on block[0..63].
// Note that the DCT used here is the DCT-2 with the first term multiplied by
// 1/sqrt(2) and the result scaled by 1/2.
void ComputeBlockDCTDouble(double block[64]);
// Performs in-place floating point 8x8 inverse DCT on block[0..63].
void ComputeBlockIDCTDouble(double block[64]);
} // namespace guetzli
#endif // GUETZLI_DCT_DOUBLE_H_
================================================
FILE: guetzli/debug_print.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/debug_print.h"
namespace guetzli {
void PrintDebug(ProcessStats* stats, std::string s) {
if (stats->debug_output) {
stats->debug_output->append(s);
}
if (stats->debug_output_file) {
fprintf(stats->debug_output_file, "%s", s.c_str());
}
}
} // namespace guetzli
================================================
FILE: guetzli/debug_print.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_DEBUG_PRINT_H_
#define GUETZLI_DEBUG_PRINT_H_
#include "guetzli/stats.h"
namespace guetzli {
void PrintDebug(ProcessStats* stats, std::string s);
} // namespace guetzli
#define GUETZLI_LOG(stats, ...) \
do { \
char debug_string[1024]; \
int res = snprintf(debug_string, sizeof(debug_string), \
__VA_ARGS__); \
assert(res > 0 && "expected successful printing"); \
(void)res; \
debug_string[sizeof(debug_string) - 1] = '\0'; \
::guetzli::PrintDebug( \
stats, std::string(debug_string)); \
} while (0)
#define GUETZLI_LOG_QUANT(stats, q) \
for (int y = 0; y < 8; ++y) { \
for (int c = 0; c < 3; ++c) { \
for (int x = 0; x < 8; ++x) \
GUETZLI_LOG(stats, " %2d", (q)[c][8 * y + x]); \
GUETZLI_LOG(stats, " "); \
} \
GUETZLI_LOG(stats, "\n"); \
}
#endif // GUETZLI_DEBUG_PRINT_H_
================================================
FILE: guetzli/entropy_encode.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Entropy encoding (Huffman) utilities.
#include "guetzli/entropy_encode.h"
#include
#include
namespace guetzli {
bool SetDepth(int p0, HuffmanTree *pool, uint8_t *depth, int max_depth) {
int stack[17];
int level = 0;
int p = p0;
assert(max_depth <= 16);
stack[0] = -1;
while (true) {
if (pool[p].index_left_ >= 0) {
level++;
if (level > max_depth) return false;
stack[level] = pool[p].index_right_or_value_;
p = pool[p].index_left_;
continue;
} else {
depth[pool[p].index_right_or_value_] = static_cast(level);
}
while (level >= 0 && stack[level] == -1) level--;
if (level < 0) return true;
p = stack[level];
stack[level] = -1;
}
}
// Sort the root nodes, least popular first.
static inline bool SortHuffmanTree(const HuffmanTree& v0,
const HuffmanTree& v1) {
if (v0.total_count_ != v1.total_count_) {
return v0.total_count_ < v1.total_count_;
}
return v0.index_right_or_value_ > v1.index_right_or_value_;
}
// This function will create a Huffman tree.
//
// The catch here is that the tree cannot be arbitrarily deep.
// Brotli specifies a maximum depth of 15 bits for "code trees"
// and 7 bits for "code length code trees."
//
// count_limit is the value that is to be faked as the minimum value
// and this minimum value is raised until the tree matches the
// maximum length requirement.
//
// This algorithm is not of excellent performance for very long data blocks,
// especially when population counts are longer than 2**tree_limit, but
// we are not planning to use this with extremely long blocks.
//
// See http://en.wikipedia.org/wiki/Huffman_coding
void CreateHuffmanTree(const uint32_t *data,
const size_t length,
const int tree_limit,
HuffmanTree* tree,
uint8_t *depth) {
// For block sizes below 64 kB, we never need to do a second iteration
// of this loop. Probably all of our block sizes will be smaller than
// that, so this loop is mostly of academic interest. If we actually
// would need this, we would be better off with the Katajainen algorithm.
for (uint32_t count_limit = 1; ; count_limit *= 2) {
size_t n = 0;
for (size_t i = length; i != 0;) {
--i;
if (data[i]) {
const uint32_t count = std::max(data[i], count_limit);
tree[n++] = HuffmanTree(count, -1, static_cast(i));
}
}
if (n == 1) {
depth[tree[0].index_right_or_value_] = 1; // Only one element.
break;
}
std::sort(tree, tree + n, SortHuffmanTree);
// The nodes are:
// [0, n): the sorted leaf nodes that we start with.
// [n]: we add a sentinel here.
// [n + 1, 2n): new parent nodes are added here, starting from
// (n+1). These are naturally in ascending order.
// [2n]: we add a sentinel at the end as well.
// There will be (2n+1) elements at the end.
const HuffmanTree sentinel(~static_cast(0), -1, -1);
tree[n] = sentinel;
tree[n + 1] = sentinel;
size_t i = 0; // Points to the next leaf node.
size_t j = n + 1; // Points to the next non-leaf node.
for (size_t k = n - 1; k != 0; --k) {
size_t left, right;
if (tree[i].total_count_ <= tree[j].total_count_) {
left = i;
++i;
} else {
left = j;
++j;
}
if (tree[i].total_count_ <= tree[j].total_count_) {
right = i;
++i;
} else {
right = j;
++j;
}
// The sentinel node becomes the parent node.
size_t j_end = 2 * n - k;
tree[j_end].total_count_ =
tree[left].total_count_ + tree[right].total_count_;
tree[j_end].index_left_ = static_cast(left);
tree[j_end].index_right_or_value_ = static_cast(right);
// Add back the last sentinel node.
tree[j_end + 1] = sentinel;
}
if (SetDepth(static_cast(2 * n - 1), &tree[0], depth, tree_limit)) {
/* We need to pack the Huffman tree in tree_limit bits. If this was not
successful, add fake entities to the lowest values and retry. */
break;
}
}
}
} // namespace guetzli
================================================
FILE: guetzli/entropy_encode.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Entropy encoding (Huffman) utilities.
#ifndef GUETZLI_ENTROPY_ENCODE_H_
#define GUETZLI_ENTROPY_ENCODE_H_
#include
#include
namespace guetzli {
// A node of a Huffman tree.
struct HuffmanTree {
HuffmanTree() {}
HuffmanTree(uint32_t count, int16_t left, int16_t right)
: total_count_(count),
index_left_(left),
index_right_or_value_(right) {
}
uint32_t total_count_;
int16_t index_left_;
int16_t index_right_or_value_;
};
bool SetDepth(int p, HuffmanTree *pool, uint8_t *depth, int max_depth);
// This function will create a Huffman tree.
//
// The (data,length) contains the population counts.
// The tree_limit is the maximum bit depth of the Huffman codes.
//
// The depth contains the tree, i.e., how many bits are used for
// the symbol.
//
// The actual Huffman tree is constructed in the tree[] array, which has to
// be at least 2 * length + 1 long.
//
// See http://en.wikipedia.org/wiki/Huffman_coding
void CreateHuffmanTree(const uint32_t *data,
const size_t length,
const int tree_limit,
HuffmanTree* tree,
uint8_t *depth);
} // namespace guetzli
#endif // GUETZLI_ENTROPY_ENCODE_H_
================================================
FILE: guetzli/fast_log.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_FAST_LOG_H_
#define GUETZLI_FAST_LOG_H_
#include
namespace guetzli {
inline int Log2FloorNonZero(uint32_t n) {
#ifdef __GNUC__
return 31 ^ __builtin_clz(n);
#else
unsigned int result = 0;
while (n >>= 1) result++;
return result;
#endif
}
inline int Log2Floor(uint32_t n) {
return n == 0 ? -1 : Log2FloorNonZero(n);
}
} // namespace guetzli
#endif // GUETZLI_FAST_LOG_H_
================================================
FILE: guetzli/fdct.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Integer implementation of the Discrete Cosine Transform (DCT)
//
// Note! DCT output is kept scaled by 16, to retain maximum 16bit precision
#include "guetzli/fdct.h"
namespace guetzli {
namespace {
///////////////////////////////////////////////////////////////////////////////
// Cosine table: C(k) = cos(k.pi/16)/sqrt(2), k = 1..7 using 15 bits signed
const coeff_t kTable04[7] = { 22725, 21407, 19266, 16384, 12873, 8867, 4520 };
// rows #1 and #7 are pre-multiplied by 2.C(1) before the 2nd pass.
// This multiply is merged in the table of constants used during 1st pass:
const coeff_t kTable17[7] = { 31521, 29692, 26722, 22725, 17855, 12299, 6270 };
// rows #2 and #6 are pre-multiplied by 2.C(2):
const coeff_t kTable26[7] = { 29692, 27969, 25172, 21407, 16819, 11585, 5906 };
// rows #3 and #5 are pre-multiplied by 2.C(3):
const coeff_t kTable35[7] = { 26722, 25172, 22654, 19266, 15137, 10426, 5315 };
///////////////////////////////////////////////////////////////////////////////
// Constants (15bit precision) and C macros for IDCT vertical pass
#define kTan1 (13036) // = tan(pi/16)
#define kTan2 (27146) // = tan(2.pi/16) = sqrt(2) - 1.
#define kTan3m1 (-21746) // = tan(3.pi/16) - 1
#define k2Sqrt2 (23170) // = 1 / 2.sqrt(2)
// performs: {a,b} <- {a-b, a+b}, without saturation
#define BUTTERFLY(a, b) do { \
SUB((a), (b)); \
ADD((b), (b)); \
ADD((b), (a)); \
} while (0)
///////////////////////////////////////////////////////////////////////////////
// Constants for DCT horizontal pass
// Note about the CORRECT_LSB macro:
// using 16bit fixed-point constants, we often compute products like:
// p = (A*x + B*y + 32768) >> 16 by adding two sub-terms q = (A*x) >> 16
// and r = (B*y) >> 16 together. Statistically, we have p = q + r + 1
// in 3/4 of the cases. This can be easily seen from the relation:
// (a + b + 1) >> 1 = (a >> 1) + (b >> 1) + ((a|b)&1)
// The approximation we are doing is replacing ((a|b)&1) by 1.
// In practice, this is a slightly more involved because the constants A and B
// have also been rounded compared to their exact floating point value.
// However, all in all the correction is quite small, and CORRECT_LSB can
// be defined empty if needed.
#define COLUMN_DCT8(in) do { \
LOAD(m0, (in)[0 * 8]); \
LOAD(m2, (in)[2 * 8]); \
LOAD(m7, (in)[7 * 8]); \
LOAD(m5, (in)[5 * 8]); \
\
BUTTERFLY(m0, m7); \
BUTTERFLY(m2, m5); \
\
LOAD(m3, (in)[3 * 8]); \
LOAD(m4, (in)[4 * 8]); \
BUTTERFLY(m3, m4); \
\
LOAD(m6, (in)[6 * 8]); \
LOAD(m1, (in)[1 * 8]); \
BUTTERFLY(m1, m6); \
BUTTERFLY(m7, m4); \
BUTTERFLY(m6, m5); \
\
/* RowIdct() needs 15bits fixed-point input, when the output from */ \
/* ColumnIdct() would be 12bits. We are better doing the shift by 3 */ \
/* now instead of in RowIdct(), because we have some multiplies to */ \
/* perform, that can take advantage of the extra 3bits precision. */ \
LSHIFT(m4, 3); \
LSHIFT(m5, 3); \
BUTTERFLY(m4, m5); \
STORE16((in)[0 * 8], m5); \
STORE16((in)[4 * 8], m4); \
\
LSHIFT(m7, 3); \
LSHIFT(m6, 3); \
LSHIFT(m3, 3); \
LSHIFT(m0, 3); \
\
LOAD_CST(m4, kTan2); \
m5 = m4; \
MULT(m4, m7); \
MULT(m5, m6); \
SUB(m4, m6); \
ADD(m5, m7); \
STORE16((in)[2 * 8], m5); \
STORE16((in)[6 * 8], m4); \
\
/* We should be multiplying m6 by C4 = 1/sqrt(2) here, but we only have */ \
/* the k2Sqrt2 = 1/(2.sqrt(2)) constant that fits into 15bits. So we */ \
/* shift by 4 instead of 3 to compensate for the additional 1/2 factor. */ \
LOAD_CST(m6, k2Sqrt2); \
LSHIFT(m2, 3 + 1); \
LSHIFT(m1, 3 + 1); \
BUTTERFLY(m1, m2); \
MULT(m2, m6); \
MULT(m1, m6); \
BUTTERFLY(m3, m1); \
BUTTERFLY(m0, m2); \
\
LOAD_CST(m4, kTan3m1); \
LOAD_CST(m5, kTan1); \
m7 = m3; \
m6 = m1; \
MULT(m3, m4); \
MULT(m1, m5); \
\
ADD(m3, m7); \
ADD(m1, m2); \
CORRECT_LSB(m1); \
CORRECT_LSB(m3); \
MULT(m4, m0); \
MULT(m5, m2); \
ADD(m4, m0); \
SUB(m0, m3); \
ADD(m7, m4); \
SUB(m5, m6); \
\
STORE16((in)[1 * 8], m1); \
STORE16((in)[3 * 8], m0); \
STORE16((in)[5 * 8], m7); \
STORE16((in)[7 * 8], m5); \
} while (0)
// these are the macro required by COLUMN_*
#define LOAD_CST(dst, src) (dst) = (src)
#define LOAD(dst, src) (dst) = (src)
#define MULT(a, b) (a) = (((a) * (b)) >> 16)
#define ADD(a, b) (a) = (a) + (b)
#define SUB(a, b) (a) = (a) - (b)
#define LSHIFT(a, n) (a) = ((a) << (n))
#define STORE16(a, b) (a) = (b)
#define CORRECT_LSB(a) (a) += 1
// DCT vertical pass
inline void ColumnDct(coeff_t* in) {
for (int i = 0; i < 8; ++i) {
int m0, m1, m2, m3, m4, m5, m6, m7;
COLUMN_DCT8(in + i);
}
}
// DCT horizontal pass
// We don't really need to round before descaling, since we
// still have 4 bits of precision left as final scaled output.
#define DESCALE(a) static_cast((a) >> 16)
void RowDct(coeff_t* in, const coeff_t* table) {
// The Fourier transform is an unitary operator, so we're basically
// doing the transpose of RowIdct()
const int a0 = in[0] + in[7];
const int b0 = in[0] - in[7];
const int a1 = in[1] + in[6];
const int b1 = in[1] - in[6];
const int a2 = in[2] + in[5];
const int b2 = in[2] - in[5];
const int a3 = in[3] + in[4];
const int b3 = in[3] - in[4];
// even part
const int C2 = table[1];
const int C4 = table[3];
const int C6 = table[5];
const int c0 = a0 + a3;
const int c1 = a0 - a3;
const int c2 = a1 + a2;
const int c3 = a1 - a2;
in[0] = DESCALE(C4 * (c0 + c2));
in[4] = DESCALE(C4 * (c0 - c2));
in[2] = DESCALE(C2 * c1 + C6 * c3);
in[6] = DESCALE(C6 * c1 - C2 * c3);
// odd part
const int C1 = table[0];
const int C3 = table[2];
const int C5 = table[4];
const int C7 = table[6];
in[1] = DESCALE(C1 * b0 + C3 * b1 + C5 * b2 + C7 * b3);
in[3] = DESCALE(C3 * b0 - C7 * b1 - C1 * b2 - C5 * b3);
in[5] = DESCALE(C5 * b0 - C1 * b1 + C7 * b2 + C3 * b3);
in[7] = DESCALE(C7 * b0 - C5 * b1 + C3 * b2 - C1 * b3);
}
#undef DESCALE
#undef LOAD_CST
#undef LOAD
#undef MULT
#undef ADD
#undef SUB
#undef LSHIFT
#undef STORE16
#undef CORRECT_LSB
#undef kTan1
#undef kTan2
#undef kTan3m1
#undef k2Sqrt2
#undef BUTTERFLY
#undef COLUMN_DCT8
} // namespace
///////////////////////////////////////////////////////////////////////////////
// visible FDCT callable functions
void ComputeBlockDCT(coeff_t* coeffs) {
ColumnDct(coeffs);
RowDct(coeffs + 0 * 8, kTable04);
RowDct(coeffs + 1 * 8, kTable17);
RowDct(coeffs + 2 * 8, kTable26);
RowDct(coeffs + 3 * 8, kTable35);
RowDct(coeffs + 4 * 8, kTable04);
RowDct(coeffs + 5 * 8, kTable35);
RowDct(coeffs + 6 * 8, kTable26);
RowDct(coeffs + 7 * 8, kTable17);
}
} // namespace guetzli
================================================
FILE: guetzli/fdct.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_FDCT_H_
#define GUETZLI_FDCT_H_
#include "guetzli/jpeg_data.h"
namespace guetzli {
// Computes the DCT (Discrete Cosine Transform) of the 8x8 array in 'block',
// scaled up by a factor of 16. The values in 'block' are laid out row-by-row
// and the result is written to the same memory area.
void ComputeBlockDCT(coeff_t* block);
} // namespace guetzli
#endif // GUETZLI_FDCT_H_
================================================
FILE: guetzli/gamma_correct.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/gamma_correct.h"
#include
namespace guetzli {
const double* NewSrgb8ToLinearTable() {
double* table = new double[256];
int i = 0;
for (; i < 11; ++i) {
table[i] = i / 12.92;
}
for (; i < 256; ++i) {
table[i] = 255.0 * std::pow(((i / 255.0) + 0.055) / 1.055, 2.4);
}
return table;
}
const double* Srgb8ToLinearTable() {
static const double* const kSrgb8ToLinearTable = NewSrgb8ToLinearTable();
return kSrgb8ToLinearTable;
}
} // namespace guetzli
================================================
FILE: guetzli/gamma_correct.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_GAMMA_CORRECT_H_
#define GUETZLI_GAMMA_CORRECT_H_
namespace guetzli {
const double* Srgb8ToLinearTable();
} // namespace guetzli
#endif // GUETZLI_GAMMA_CORRECT_H_
================================================
FILE: guetzli/guetzli.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include "png.h"
#include "guetzli/jpeg_data.h"
#include "guetzli/jpeg_data_reader.h"
#include "guetzli/processor.h"
#include "guetzli/quality.h"
#include "guetzli/stats.h"
namespace {
constexpr int kDefaultJPEGQuality = 95;
// An upper estimate of memory usage of Guetzli. The bound is
// max(kLowerMemusaeMB * 1<<20, pixel_count * kBytesPerPixel)
constexpr int kBytesPerPixel = 350;
constexpr int kLowestMemusageMB = 100; // in MB
constexpr int kDefaultMemlimitMB = 6000; // in MB
inline uint8_t BlendOnBlack(const uint8_t val, const uint8_t alpha) {
return (static_cast(val) * static_cast(alpha) + 128) / 255;
}
bool ReadPNG(const std::string& data, int* xsize, int* ysize,
std::vector* rgb) {
png_structp png_ptr =
png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
if (!png_ptr) {
return false;
}
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, nullptr, nullptr);
return false;
}
if (setjmp(png_jmpbuf(png_ptr)) != 0) {
// Ok we are here because of the setjmp.
png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
return false;
}
std::istringstream memstream(data, std::ios::in | std::ios::binary);
png_set_read_fn(png_ptr, static_cast(&memstream), [](png_structp png_ptr, png_bytep outBytes, png_size_t byteCountToRead) {
std::istringstream& memstream = *static_cast(png_get_io_ptr(png_ptr));
memstream.read(reinterpret_cast(outBytes), byteCountToRead);
if (memstream.eof()) png_error(png_ptr, "unexpected end of data");
if (memstream.fail()) png_error(png_ptr, "read from memory error");
});
// The png_transforms flags are as follows:
// packing == convert 1,2,4 bit images,
// strip == 16 -> 8 bits / channel,
// shift == use sBIT dynamics, and
// expand == palettes -> rgb, grayscale -> 8 bit images, tRNS -> alpha.
const unsigned int png_transforms =
PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_STRIP_16;
png_read_png(png_ptr, info_ptr, png_transforms, nullptr);
png_bytep* row_pointers = png_get_rows(png_ptr, info_ptr);
*xsize = png_get_image_width(png_ptr, info_ptr);
*ysize = png_get_image_height(png_ptr, info_ptr);
rgb->resize(3 * (*xsize) * (*ysize));
const int components = png_get_channels(png_ptr, info_ptr);
switch (components) {
case 1: {
// GRAYSCALE
for (int y = 0; y < *ysize; ++y) {
const uint8_t* row_in = row_pointers[y];
uint8_t* row_out = &(*rgb)[3 * y * (*xsize)];
for (int x = 0; x < *xsize; ++x) {
const uint8_t gray = row_in[x];
row_out[3 * x + 0] = gray;
row_out[3 * x + 1] = gray;
row_out[3 * x + 2] = gray;
}
}
break;
}
case 2: {
// GRAYSCALE + ALPHA
for (int y = 0; y < *ysize; ++y) {
const uint8_t* row_in = row_pointers[y];
uint8_t* row_out = &(*rgb)[3 * y * (*xsize)];
for (int x = 0; x < *xsize; ++x) {
const uint8_t gray = BlendOnBlack(row_in[2 * x], row_in[2 * x + 1]);
row_out[3 * x + 0] = gray;
row_out[3 * x + 1] = gray;
row_out[3 * x + 2] = gray;
}
}
break;
}
case 3: {
// RGB
for (int y = 0; y < *ysize; ++y) {
const uint8_t* row_in = row_pointers[y];
uint8_t* row_out = &(*rgb)[3 * y * (*xsize)];
memcpy(row_out, row_in, 3 * (*xsize));
}
break;
}
case 4: {
// RGBA
for (int y = 0; y < *ysize; ++y) {
const uint8_t* row_in = row_pointers[y];
uint8_t* row_out = &(*rgb)[3 * y * (*xsize)];
for (int x = 0; x < *xsize; ++x) {
const uint8_t alpha = row_in[4 * x + 3];
row_out[3 * x + 0] = BlendOnBlack(row_in[4 * x + 0], alpha);
row_out[3 * x + 1] = BlendOnBlack(row_in[4 * x + 1], alpha);
row_out[3 * x + 2] = BlendOnBlack(row_in[4 * x + 2], alpha);
}
}
break;
}
default:
png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
return false;
}
png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
return true;
}
std::string ReadFileOrDie(const char* filename) {
bool read_from_stdin = strncmp(filename, "-", 2) == 0;
FILE* f = read_from_stdin ? stdin : fopen(filename, "rb");
if (!f) {
perror("Can't open input file");
exit(1);
}
std::string result;
off_t buffer_size = 8192;
if (fseek(f, 0, SEEK_END) == 0) {
buffer_size = std::max(ftell(f), 1);
if (fseek(f, 0, SEEK_SET) != 0) {
perror("fseek");
exit(1);
}
} else if (ferror(f)) {
perror("fseek");
exit(1);
}
std::unique_ptr buf(new char[buffer_size]);
while (!feof(f)) {
size_t read_bytes = fread(buf.get(), sizeof(char), buffer_size, f);
if (ferror(f)) {
perror("fread");
exit(1);
}
result.append(buf.get(), read_bytes);
}
fclose(f);
return result;
}
void WriteFileOrDie(const char* filename, const std::string& contents) {
bool write_to_stdout = strncmp(filename, "-", 2) == 0;
FILE* f = write_to_stdout ? stdout : fopen(filename, "wb");
if (!f) {
perror("Can't open output file for writing");
exit(1);
}
if (fwrite(contents.data(), 1, contents.size(), f) != contents.size()) {
perror("fwrite");
exit(1);
}
if (fclose(f) < 0) {
perror("fclose");
exit(1);
}
}
void TerminateHandler() {
fprintf(stderr, "Unhandled exception. Most likely insufficient memory available.\n"
"Make sure that there is 300MB/MPix of memory available.\n");
exit(1);
}
void Usage() {
fprintf(stderr,
"Guetzli JPEG compressor. Usage: \n"
"guetzli [flags] input_filename output_filename\n"
"\n"
"Flags:\n"
" --verbose - Print a verbose trace of all attempts to standard output.\n"
" --quality Q - Visual quality to aim for, expressed as a JPEG quality value.\n"
" Default value is %d.\n"
" --memlimit M - Memory limit in MB. Guetzli will fail if unable to stay under\n"
" the limit. Default limit is %d MB.\n"
" --nomemlimit - Do not limit memory usage.\n", kDefaultJPEGQuality, kDefaultMemlimitMB);
exit(1);
}
} // namespace
int main(int argc, char** argv) {
std::set_terminate(TerminateHandler);
int verbose = 0;
int quality = kDefaultJPEGQuality;
int memlimit_mb = kDefaultMemlimitMB;
int opt_idx = 1;
for(;opt_idx < argc;opt_idx++) {
if (strnlen(argv[opt_idx], 2) < 2 || argv[opt_idx][0] != '-' || argv[opt_idx][1] != '-')
break;
if (!strcmp(argv[opt_idx], "--verbose")) {
verbose = 1;
} else if (!strcmp(argv[opt_idx], "--quality")) {
opt_idx++;
if (opt_idx >= argc)
Usage();
quality = atoi(argv[opt_idx]);
} else if (!strcmp(argv[opt_idx], "--memlimit")) {
opt_idx++;
if (opt_idx >= argc)
Usage();
memlimit_mb = atoi(argv[opt_idx]);
} else if (!strcmp(argv[opt_idx], "--nomemlimit")) {
memlimit_mb = -1;
} else if (!strcmp(argv[opt_idx], "--")) {
opt_idx++;
break;
} else {
fprintf(stderr, "Unknown commandline flag: %s\n", argv[opt_idx]);
Usage();
}
}
if (argc - opt_idx != 2) {
Usage();
}
std::string in_data = ReadFileOrDie(argv[opt_idx]);
std::string out_data;
guetzli::Params params;
params.butteraugli_target = static_cast(
guetzli::ButteraugliScoreForQuality(quality));
guetzli::ProcessStats stats;
if (verbose) {
stats.debug_output_file = stderr;
}
static const unsigned char kPNGMagicBytes[] = {
0x89, 'P', 'N', 'G', '\r', '\n', 0x1a, '\n',
};
if (in_data.size() >= 8 &&
memcmp(in_data.data(), kPNGMagicBytes, sizeof(kPNGMagicBytes)) == 0) {
int xsize, ysize;
std::vector rgb;
if (!ReadPNG(in_data, &xsize, &ysize, &rgb)) {
fprintf(stderr, "Error reading PNG data from input file\n");
return 1;
}
double pixels = static_cast(xsize) * ysize;
if (memlimit_mb != -1
&& (pixels * kBytesPerPixel / (1 << 20) > memlimit_mb
|| memlimit_mb < kLowestMemusageMB)) {
fprintf(stderr, "Memory limit would be exceeded. Failing.\n");
return 1;
}
if (!guetzli::Process(params, &stats, rgb, xsize, ysize, &out_data)) {
fprintf(stderr, "Guetzli processing failed\n");
return 1;
}
} else {
guetzli::JPEGData jpg_header;
if (!guetzli::ReadJpeg(in_data, guetzli::JPEG_READ_HEADER, &jpg_header)) {
fprintf(stderr, "Error reading JPG data from input file\n");
return 1;
}
double pixels = static_cast(jpg_header.width) * jpg_header.height;
if (memlimit_mb != -1
&& (pixels * kBytesPerPixel / (1 << 20) > memlimit_mb
|| memlimit_mb < kLowestMemusageMB)) {
fprintf(stderr, "Memory limit would be exceeded. Failing.\n");
return 1;
}
if (!guetzli::Process(params, &stats, in_data, &out_data)) {
fprintf(stderr, "Guetzli processing failed\n");
return 1;
}
}
WriteFileOrDie(argv[opt_idx + 1], out_data);
return 0;
}
================================================
FILE: guetzli/idct.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Integer implementation of the Inverse Discrete Cosine Transform (IDCT).
#include "guetzli/idct.h"
#include
#include
namespace guetzli {
// kIDCTMatrix[8*x+u] = alpha(u)*cos((2*x+1)*u*M_PI/16)*sqrt(2), with fixed 13
// bit precision, where alpha(0) = 1/sqrt(2) and alpha(u) = 1 for u > 0.
// Some coefficients are off by +-1 to mimick libjpeg's behaviour.
static const int kIDCTMatrix[kDCTBlockSize] = {
8192, 11363, 10703, 9633, 8192, 6437, 4433, 2260,
8192, 9633, 4433, -2259, -8192, -11362, -10704, -6436,
8192, 6437, -4433, -11362, -8192, 2261, 10704, 9633,
8192, 2260, -10703, -6436, 8192, 9633, -4433, -11363,
8192, -2260, -10703, 6436, 8192, -9633, -4433, 11363,
8192, -6437, -4433, 11362, -8192, -2261, 10704, -9633,
8192, -9633, 4433, 2259, -8192, 11362, -10704, 6436,
8192, -11363, 10703, -9633, 8192, -6437, 4433, -2260,
};
// Computes out[x] = sum{kIDCTMatrix[8*x+u]*in[u*stride]; for u in [0..7]}
inline void Compute1dIDCT(const coeff_t* in, const int stride, int out[8]) {
int tmp0, tmp1, tmp2, tmp3, tmp4;
tmp1 = kIDCTMatrix[0] * in[0];
out[0] = out[1] = out[2] = out[3] = out[4] = out[5] = out[6] = out[7] = tmp1;
tmp0 = in[stride];
tmp1 = kIDCTMatrix[ 1] * tmp0;
tmp2 = kIDCTMatrix[ 9] * tmp0;
tmp3 = kIDCTMatrix[17] * tmp0;
tmp4 = kIDCTMatrix[25] * tmp0;
out[0] += tmp1;
out[1] += tmp2;
out[2] += tmp3;
out[3] += tmp4;
out[4] -= tmp4;
out[5] -= tmp3;
out[6] -= tmp2;
out[7] -= tmp1;
tmp0 = in[2 * stride];
tmp1 = kIDCTMatrix[ 2] * tmp0;
tmp2 = kIDCTMatrix[10] * tmp0;
out[0] += tmp1;
out[1] += tmp2;
out[2] -= tmp2;
out[3] -= tmp1;
out[4] -= tmp1;
out[5] -= tmp2;
out[6] += tmp2;
out[7] += tmp1;
tmp0 = in[3 * stride];
tmp1 = kIDCTMatrix[ 3] * tmp0;
tmp2 = kIDCTMatrix[11] * tmp0;
tmp3 = kIDCTMatrix[19] * tmp0;
tmp4 = kIDCTMatrix[27] * tmp0;
out[0] += tmp1;
out[1] += tmp2;
out[2] += tmp3;
out[3] += tmp4;
out[4] -= tmp4;
out[5] -= tmp3;
out[6] -= tmp2;
out[7] -= tmp1;
tmp0 = in[4 * stride];
tmp1 = kIDCTMatrix[ 4] * tmp0;
out[0] += tmp1;
out[1] -= tmp1;
out[2] -= tmp1;
out[3] += tmp1;
out[4] += tmp1;
out[5] -= tmp1;
out[6] -= tmp1;
out[7] += tmp1;
tmp0 = in[5 * stride];
tmp1 = kIDCTMatrix[ 5] * tmp0;
tmp2 = kIDCTMatrix[13] * tmp0;
tmp3 = kIDCTMatrix[21] * tmp0;
tmp4 = kIDCTMatrix[29] * tmp0;
out[0] += tmp1;
out[1] += tmp2;
out[2] += tmp3;
out[3] += tmp4;
out[4] -= tmp4;
out[5] -= tmp3;
out[6] -= tmp2;
out[7] -= tmp1;
tmp0 = in[6 * stride];
tmp1 = kIDCTMatrix[ 6] * tmp0;
tmp2 = kIDCTMatrix[14] * tmp0;
out[0] += tmp1;
out[1] += tmp2;
out[2] -= tmp2;
out[3] -= tmp1;
out[4] -= tmp1;
out[5] -= tmp2;
out[6] += tmp2;
out[7] += tmp1;
tmp0 = in[7 * stride];
tmp1 = kIDCTMatrix[ 7] * tmp0;
tmp2 = kIDCTMatrix[15] * tmp0;
tmp3 = kIDCTMatrix[23] * tmp0;
tmp4 = kIDCTMatrix[31] * tmp0;
out[0] += tmp1;
out[1] += tmp2;
out[2] += tmp3;
out[3] += tmp4;
out[4] -= tmp4;
out[5] -= tmp3;
out[6] -= tmp2;
out[7] -= tmp1;
}
void ComputeBlockIDCT(const coeff_t* block, uint8_t* out) {
coeff_t colidcts[kDCTBlockSize];
const int kColScale = 11;
const int kColRound = 1 << (kColScale - 1);
for (int x = 0; x < 8; ++x) {
int colbuf[8] = { 0 };
Compute1dIDCT(&block[x], 8, colbuf);
for (int y = 0; y < 8; ++y) {
colidcts[8 * y + x] = (colbuf[y] + kColRound) >> kColScale;
}
}
const int kRowScale = 18;
const int kRowRound = 257 << (kRowScale - 1); // includes offset by 128
for (int y = 0; y < 8; ++y) {
const int rowidx = 8 * y;
int rowbuf[8] = { 0 };
Compute1dIDCT(&colidcts[rowidx], 1, rowbuf);
for (int x = 0; x < 8; ++x) {
out[rowidx + x] =
std::max(0, std::min(255, (rowbuf[x] + kRowRound) >> kRowScale));
}
}
}
} // namespace guetzli
================================================
FILE: guetzli/idct.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_IDCT_H_
#define GUETZLI_IDCT_H_
#include "guetzli/jpeg_data.h"
namespace guetzli {
// Fills in 'result' with the inverse DCT of 'block'.
// The arguments 'block' and 'result' point to 8x8 arrays that are arranged in
// a row-by-row memory layout.
void ComputeBlockIDCT(const coeff_t* block, uint8_t* result);
} // namespace guetzli
#endif // GUETZLI_IDCT_H_
================================================
FILE: guetzli/jpeg_bit_writer.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_JPEG_BIT_WRITER_H_
#define GUETZLI_JPEG_BIT_WRITER_H_
#include
#include
namespace guetzli {
// Returns non-zero if and only if x has a zero byte, i.e. one of
// x & 0xff, x & 0xff00, ..., x & 0xff00000000000000 is zero.
inline uint64_t HasZeroByte(uint64_t x) {
return (x - 0x0101010101010101ULL) & ~x & 0x8080808080808080ULL;
}
// Handles the packing of bits into output bytes.
struct BitWriter {
explicit BitWriter(size_t length) : len(length),
data(new uint8_t[len]),
pos(0),
put_buffer(0),
put_bits(64),
overflow(false) {}
void WriteBits(int nbits, uint64_t bits) {
put_bits -= nbits;
put_buffer |= (bits << put_bits);
if (put_bits <= 16) {
// At this point we are ready to emit the most significant 6 bytes of
// put_buffer_ to the output.
// The JPEG format requires that after every 0xff byte in the entropy
// coded section, there is a zero byte, therefore we first check if any of
// the 6 most significant bytes of put_buffer_ is 0xff.
if (HasZeroByte(~put_buffer | 0xffff)) {
// We have a 0xff byte somewhere, examine each byte and append a zero
// byte if necessary.
EmitByte((put_buffer >> 56) & 0xff);
EmitByte((put_buffer >> 48) & 0xff);
EmitByte((put_buffer >> 40) & 0xff);
EmitByte((put_buffer >> 32) & 0xff);
EmitByte((put_buffer >> 24) & 0xff);
EmitByte((put_buffer >> 16) & 0xff);
} else if (pos + 6 < len) {
// We don't have any 0xff bytes, output all 6 bytes without checking.
data[pos] = (put_buffer >> 56) & 0xff;
data[pos + 1] = (put_buffer >> 48) & 0xff;
data[pos + 2] = (put_buffer >> 40) & 0xff;
data[pos + 3] = (put_buffer >> 32) & 0xff;
data[pos + 4] = (put_buffer >> 24) & 0xff;
data[pos + 5] = (put_buffer >> 16) & 0xff;
pos += 6;
} else {
overflow = true;
}
put_buffer <<= 48;
put_bits += 48;
}
}
// Writes the given byte to the output, writes an extra zero if byte is 0xff.
void EmitByte(int byte) {
if (pos < len) {
data[pos++] = byte;
} else {
overflow = true;
}
if (byte == 0xff) {
EmitByte(0);
}
}
void JumpToByteBoundary() {
while (put_bits <= 56) {
int c = (put_buffer >> 56) & 0xff;
EmitByte(c);
put_buffer <<= 8;
put_bits += 8;
}
if (put_bits < 64) {
int padmask = 0xff >> (64 - put_bits);
int c = ((put_buffer >> 56) & ~padmask) | padmask;
EmitByte(c);
}
put_buffer = 0;
put_bits = 64;
}
size_t len;
std::unique_ptr data;
size_t pos;
uint64_t put_buffer;
int put_bits;
bool overflow;
};
} // namespace guetzli
#endif // GUETZLI_JPEG_BIT_WRITER_H_
================================================
FILE: guetzli/jpeg_data.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/jpeg_data.h"
#include
#include
namespace guetzli {
bool JPEGData::Is420() const {
return (components.size() == 3 &&
max_h_samp_factor == 2 &&
max_v_samp_factor == 2 &&
components[0].h_samp_factor == 2 &&
components[0].v_samp_factor == 2 &&
components[1].h_samp_factor == 1 &&
components[1].v_samp_factor == 1 &&
components[2].h_samp_factor == 1 &&
components[2].v_samp_factor == 1);
}
bool JPEGData::Is444() const {
return (components.size() == 3 &&
max_h_samp_factor == 1 &&
max_v_samp_factor == 1 &&
components[0].h_samp_factor == 1 &&
components[0].v_samp_factor == 1 &&
components[1].h_samp_factor == 1 &&
components[1].v_samp_factor == 1 &&
components[2].h_samp_factor == 1 &&
components[2].v_samp_factor == 1);
}
void InitJPEGDataForYUV444(int w, int h, JPEGData* jpg) {
jpg->width = w;
jpg->height = h;
jpg->max_h_samp_factor = 1;
jpg->max_v_samp_factor = 1;
jpg->MCU_rows = (h + 7) >> 3;
jpg->MCU_cols = (w + 7) >> 3;
jpg->quant.resize(3);
jpg->components.resize(3);
for (int i = 0; i < 3; ++i) {
JPEGComponent* c = &jpg->components[i];
c->id = i;
c->h_samp_factor = 1;
c->v_samp_factor = 1;
c->quant_idx = i;
c->width_in_blocks = jpg->MCU_cols;
c->height_in_blocks = jpg->MCU_rows;
c->num_blocks = c->width_in_blocks * c->height_in_blocks;
c->coeffs.resize(c->num_blocks * kDCTBlockSize);
}
}
void SaveQuantTables(const int q[3][kDCTBlockSize], JPEGData* jpg) {
const size_t kTableSize = kDCTBlockSize * sizeof(q[0][0]);
jpg->quant.clear();
int num_tables = 0;
for (size_t i = 0; i < jpg->components.size(); ++i) {
JPEGComponent* comp = &jpg->components[i];
// Check if we have this quant table already.
bool found = false;
for (int j = 0; j < num_tables; ++j) {
if (memcmp(&q[i][0], &jpg->quant[j].values[0], kTableSize) == 0) {
comp->quant_idx = j;
found = true;
break;
}
}
if (!found) {
JPEGQuantTable table;
memcpy(&table.values[0], &q[i][0], kTableSize);
table.precision = 0;
for (int k = 0; k < kDCTBlockSize; ++k) {
assert(table.values[k] >= 0);
assert(table.values[k] < (1 << 16));
if (table.values[k] > 0xff) {
table.precision = 1;
}
}
table.index = num_tables;
comp->quant_idx = num_tables;
jpg->quant.push_back(table);
++num_tables;
}
}
}
} // namespace guetzli
================================================
FILE: guetzli/jpeg_data.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Data structures that represent the contents of a jpeg file.
#ifndef GUETZLI_JPEG_DATA_H_
#define GUETZLI_JPEG_DATA_H_
#include
#include
#include
#include
#include "guetzli/jpeg_error.h"
namespace guetzli {
static const int kDCTBlockSize = 64;
static const int kMaxComponents = 4;
static const int kMaxQuantTables = 4;
static const int kMaxHuffmanTables = 4;
static const int kJpegHuffmanMaxBitLength = 16;
static const int kJpegHuffmanAlphabetSize = 256;
static const int kJpegDCAlphabetSize = 12;
static const int kMaxDHTMarkers = 512;
static const uint8_t kDefaultQuantMatrix[2][64] = {
{ 16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77,
24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101,
72, 92, 95, 98, 112, 100, 103, 99 },
{ 17, 18, 24, 47, 99, 99, 99, 99,
18, 21, 26, 66, 99, 99, 99, 99,
24, 26, 56, 99, 99, 99, 99, 99,
47, 66, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99 }
};
const int kJPEGNaturalOrder[80] = {
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63,
// extra entries for safety in decoder
63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63, 63
};
const int kJPEGZigZagOrder[64] = {
0, 1, 5, 6, 14, 15, 27, 28,
2, 4, 7, 13, 16, 26, 29, 42,
3, 8, 12, 17, 25, 30, 41, 43,
9, 11, 18, 24, 31, 40, 44, 53,
10, 19, 23, 32, 39, 45, 52, 54,
20, 22, 33, 38, 46, 51, 55, 60,
21, 34, 37, 47, 50, 56, 59, 61,
35, 36, 48, 49, 57, 58, 62, 63
};
// Quantization values for an 8x8 pixel block.
struct JPEGQuantTable {
JPEGQuantTable() : values(kDCTBlockSize), precision(0),
index(0), is_last(true) {}
std::vector values;
int precision;
// The index of this quantization table as it was parsed from the input JPEG.
// Each DQT marker segment contains an 'index' field, and we save this index
// here. Valid values are 0 to 3.
int index;
// Set to true if this table is the last one within its marker segment.
bool is_last;
};
// Huffman code and decoding lookup table used for DC and AC coefficients.
struct JPEGHuffmanCode {
JPEGHuffmanCode() : counts(kJpegHuffmanMaxBitLength + 1),
values(kJpegHuffmanAlphabetSize + 1),
slot_id(0),
is_last(true) {}
// Bit length histogram.
std::vector counts;
// Symbol values sorted by increasing bit lengths.
std::vector values;
// The index of the Huffman code in the current set of Huffman codes. For AC
// component Huffman codes, 0x10 is added to the index.
int slot_id;
// Set to true if this Huffman code is the last one within its marker segment.
bool is_last;
};
// Huffman table indexes used for one component of one scan.
struct JPEGComponentScanInfo {
int comp_idx;
int dc_tbl_idx;
int ac_tbl_idx;
};
// Contains information that is used in one scan.
struct JPEGScanInfo {
// Parameters used for progressive scans (named the same way as in the spec):
// Ss : Start of spectral band in zig-zag sequence.
// Se : End of spectral band in zig-zag sequence.
// Ah : Successive approximation bit position, high.
// Al : Successive approximation bit position, low.
int Ss;
int Se;
int Ah;
int Al;
std::vector components;
};
typedef int16_t coeff_t;
// Represents one component of a jpeg file.
struct JPEGComponent {
JPEGComponent() : id(0),
h_samp_factor(1),
v_samp_factor(1),
quant_idx(0),
width_in_blocks(0),
height_in_blocks(0) {}
// One-byte id of the component.
int id;
// Horizontal and vertical sampling factors.
// In interleaved mode, each minimal coded unit (MCU) has
// h_samp_factor x v_samp_factor DCT blocks from this component.
int h_samp_factor;
int v_samp_factor;
// The index of the quantization table used for this component.
size_t quant_idx;
// The dimensions of the component measured in 8x8 blocks.
int width_in_blocks;
int height_in_blocks;
int num_blocks;
// The DCT coefficients of this component, laid out block-by-block, divided
// through the quantization matrix values.
std::vector coeffs;
};
// Represents a parsed jpeg file.
struct JPEGData {
JPEGData() : width(0),
height(0),
version(0),
max_h_samp_factor(1),
max_v_samp_factor(1),
MCU_rows(0),
MCU_cols(0),
restart_interval(0),
original_jpg(NULL),
original_jpg_size(0),
error(JPEG_OK) {}
bool Is420() const;
bool Is444() const;
int width;
int height;
int version;
int max_h_samp_factor;
int max_v_samp_factor;
int MCU_rows;
int MCU_cols;
int restart_interval;
std::vector app_data;
std::vector com_data;
std::vector quant;
std::vector huffman_code;
std::vector components;
std::vector scan_info;
std::vector marker_order;
std::vector inter_marker_data;
std::string tail_data;
const uint8_t* original_jpg;
size_t original_jpg_size;
JPEGReadError error;
};
void InitJPEGDataForYUV444(int w, int h, JPEGData* jpg);
void SaveQuantTables(const int q[3][kDCTBlockSize], JPEGData* jpg);
} // namespace guetzli
#endif // GUETZLI_JPEG_DATA_H_
================================================
FILE: guetzli/jpeg_data_decoder.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/jpeg_data_decoder.h"
#include "guetzli/output_image.h"
namespace guetzli {
// Mimic libjpeg's heuristics to guess jpeg color space.
// Requires that the jpg has 3 components.
bool HasYCbCrColorSpace(const JPEGData& jpg) {
bool has_Adobe_marker = false;
uint8_t Adobe_transform = 0;
for (const std::string& app : jpg.app_data) {
if (static_cast(app[0]) == 0xe0) {
return true;
} else if (static_cast(app[0]) == 0xee && app.size() >= 15) {
has_Adobe_marker = true;
Adobe_transform = app[14];
}
}
if (has_Adobe_marker) {
return (Adobe_transform != 0);
}
const int cid0 = jpg.components[0].id;
const int cid1 = jpg.components[1].id;
const int cid2 = jpg.components[2].id;
return (cid0 != 'R' || cid1 != 'G' || cid2 != 'B');
}
std::vector DecodeJpegToRGB(const JPEGData& jpg) {
if (jpg.components.size() == 1 ||
(jpg.components.size() == 3 &&
HasYCbCrColorSpace(jpg) && (jpg.Is420() || jpg.Is444()))) {
OutputImage img(jpg.width, jpg.height);
img.CopyFromJpegData(jpg);
return img.ToSRGB();
}
return std::vector();
}
} // namespace guetzli
================================================
FILE: guetzli/jpeg_data_decoder.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Library to decode jpeg coefficients into an RGB image.
#ifndef GUETZLI_JPEG_DATA_DECODER_H_
#define GUETZLI_JPEG_DATA_DECODER_H_
#include
#include "guetzli/jpeg_data.h"
namespace guetzli {
// Decodes the parsed jpeg coefficients into an RGB image.
// There can be only either 1 or 3 image components, in either case, an RGB
// output image will be generated.
// Only YUV420 and YUV444 sampling factors are supported.
// Vector will be empty if a decoding error occurred.
std::vector DecodeJpegToRGB(const JPEGData& jpg);
// Mimic libjpeg's heuristics to guess jpeg color space.
// Requires that the jpg has 3 components.
bool HasYCbCrColorSpace(const JPEGData& jpg);
} // namespace guetzli
#endif // GUETZLI_JPEG_DATA_DECODER_H_
================================================
FILE: guetzli/jpeg_data_encoder.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/jpeg_data_encoder.h"
#include
#include
#include "guetzli/fdct.h"
namespace guetzli {
namespace {
static const int kIQuantBits = 16;
// Output of the DCT is upscaled by 16.
static const int kDCTBits = kIQuantBits + 4;
static const int kBias = 0x80 << (kDCTBits - 8);
void Quantize(coeff_t* v, int iquant) {
*v = (*v * iquant + kBias) >> kDCTBits;
}
// Single pixel rgb to 16-bit yuv conversion.
// The returned yuv values are signed integers in the
// range [-128, 127] inclusive.
inline static void RGBToYUV16(const uint8_t* const rgb,
coeff_t *out) {
enum { FRAC = 16, HALF = 1 << (FRAC - 1) };
const int r = rgb[0];
const int g = rgb[1];
const int b = rgb[2];
out[0] = (19595 * r + 38469 * g + 7471 * b - (128 << 16) + HALF) >> FRAC;
out[64] = (-11059 * r - 21709 * g + 32768 * b + HALF - 1) >> FRAC;
out[128] = (32768 * r - 27439 * g - 5329 * b + HALF - 1) >> FRAC;
}
} // namespace
void AddApp0Data(JPEGData* jpg) {
const unsigned char kApp0Data[] = {
0xe0, 0x00, 0x10, // APP0
0x4a, 0x46, 0x49, 0x46, 0x00, // 'JFIF'
0x01, 0x01, // v1.01
0x00, 0x00, 0x01, 0x00, 0x01, // aspect ratio = 1:1
0x00, 0x00 // thumbnail width/height
};
jpg->app_data.push_back(
std::string(reinterpret_cast(kApp0Data),
sizeof(kApp0Data)));
}
bool EncodeRGBToJpeg(const std::vector& rgb, int w, int h,
const int* quant, JPEGData* jpg) {
if (w < 0 || w >= 1 << 16 || h < 0 || h >= 1 << 16 ||
rgb.size() != 3 * w * h) {
return false;
}
InitJPEGDataForYUV444(w, h, jpg);
AddApp0Data(jpg);
int iquant[3 * kDCTBlockSize];
int idx = 0;
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < kDCTBlockSize; ++j) {
int v = quant[idx];
jpg->quant[i].values[j] = v;
iquant[idx++] = ((1 << kIQuantBits) + 1) / v;
}
}
// Compute YUV444 DCT coefficients.
int block_ix = 0;
for (int block_y = 0; block_y < jpg->MCU_rows; ++block_y) {
for (int block_x = 0; block_x < jpg->MCU_cols; ++block_x) {
coeff_t block[3 * kDCTBlockSize];
// RGB->YUV transform.
for (int iy = 0; iy < 8; ++iy) {
for (int ix = 0; ix < 8; ++ix) {
int y = std::min(h - 1, 8 * block_y + iy);
int x = std::min(w - 1, 8 * block_x + ix);
int p = y * w + x;
RGBToYUV16(&rgb[3 * p], &block[8 * iy + ix]);
}
}
// DCT
for (int i = 0; i < 3; ++i) {
ComputeBlockDCT(&block[i * kDCTBlockSize]);
}
// Quantization
for (int i = 0; i < 3 * 64; ++i) {
Quantize(&block[i], iquant[i]);
}
// Copy the resulting coefficients to *jpg.
for (int i = 0; i < 3; ++i) {
memcpy(&jpg->components[i].coeffs[block_ix * kDCTBlockSize],
&block[i * kDCTBlockSize], kDCTBlockSize * sizeof(block[0]));
}
++block_ix;
}
}
return true;
}
bool EncodeRGBToJpeg(const std::vector& rgb, int w, int h,
JPEGData* jpg) {
static const int quant[3 * kDCTBlockSize] = {
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
};
return EncodeRGBToJpeg(rgb, w, h, quant, jpg);
}
} // namespace guetzli
================================================
FILE: guetzli/jpeg_data_encoder.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_JPEG_DATA_ENCODER_H_
#define GUETZLI_JPEG_DATA_ENCODER_H_
#include
#include "guetzli/jpeg_data.h"
namespace guetzli {
// Adds APP0 header data.
void AddApp0Data(JPEGData* jpg);
// Creates a JPEG from the rgb pixel data. Returns true on success.
bool EncodeRGBToJpeg(const std::vector& rgb, int w, int h,
JPEGData* jpg);
// Creates a JPEG from the rgb pixel data. Returns true on success. The given
// quantization table must have 3 * kDCTBlockSize values.
bool EncodeRGBToJpeg(const std::vector& rgb, int w, int h,
const int* quant, JPEGData* jpg);
} // namespace guetzli
#endif // GUETZLI_JPEG_DATA_ENCODER_H_
================================================
FILE: guetzli/jpeg_data_reader.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/jpeg_data_reader.h"
#include
#include
#include
#include "guetzli/jpeg_huffman_decode.h"
namespace guetzli {
namespace {
// Macros for commonly used error conditions.
#define VERIFY_LEN(n) \
if (*pos + (n) > len) { \
fprintf(stderr, "Unexpected end of input: pos=%d need=%d len=%d\n", \
static_cast(*pos), static_cast(n), \
static_cast(len)); \
jpg->error = JPEG_UNEXPECTED_EOF; \
return false; \
}
#define VERIFY_INPUT(var, low, high, code) \
if (var < low || var > high) { \
fprintf(stderr, "Invalid %s: %d\n", #var, static_cast(var)); \
jpg->error = JPEG_INVALID_ ## code; \
return false; \
}
#define VERIFY_MARKER_END() \
if (start_pos + marker_len != *pos) { \
fprintf(stderr, "Invalid marker length: declared=%d actual=%d\n", \
static_cast(marker_len), \
static_cast(*pos - start_pos)); \
jpg->error = JPEG_WRONG_MARKER_SIZE; \
return false; \
}
#define EXPECT_MARKER() \
if (pos + 2 > len || data[pos] != 0xff) { \
fprintf(stderr, "Marker byte (0xff) expected, found: %d " \
"pos=%d len=%d\n", \
(pos < len ? data[pos] : 0), static_cast(pos), \
static_cast(len)); \
jpg->error = JPEG_MARKER_BYTE_NOT_FOUND; \
return false; \
}
inline int SignedLeftshift(int v, int s) {
return (v >= 0) ? (v << s) : -((-v) << s);
}
// Returns ceil(a/b).
inline int DivCeil(int a, int b) {
return (a + b - 1) / b;
}
inline int ReadUint8(const uint8_t* data, size_t* pos) {
return data[(*pos)++];
}
inline int ReadUint16(const uint8_t* data, size_t* pos) {
int v = (data[*pos] << 8) + data[*pos + 1];
*pos += 2;
return v;
}
// Reads the Start of Frame (SOF) marker segment and fills in *jpg with the
// parsed data.
bool ProcessSOF(const uint8_t* data, const size_t len,
JpegReadMode mode, size_t* pos, JPEGData* jpg) {
if (jpg->width != 0) {
fprintf(stderr, "Duplicate SOF marker.\n");
jpg->error = JPEG_DUPLICATE_SOF;
return false;
}
const size_t start_pos = *pos;
VERIFY_LEN(8);
size_t marker_len = ReadUint16(data, pos);
int precision = ReadUint8(data, pos);
int height = ReadUint16(data, pos);
int width = ReadUint16(data, pos);
int num_components = ReadUint8(data, pos);
VERIFY_INPUT(precision, 8, 8, PRECISION);
VERIFY_INPUT(height, 1, 65535, HEIGHT);
VERIFY_INPUT(width, 1, 65535, WIDTH);
VERIFY_INPUT(num_components, 1, kMaxComponents, NUMCOMP);
VERIFY_LEN(3 * num_components);
jpg->height = height;
jpg->width = width;
jpg->components.resize(num_components);
// Read sampling factors and quant table index for each component.
std::vector ids_seen(256, false);
for (size_t i = 0; i < jpg->components.size(); ++i) {
const int id = ReadUint8(data, pos);
if (ids_seen[id]) { // (cf. section B.2.2, syntax of Ci)
fprintf(stderr, "Duplicate ID %d in SOF.\n", id);
jpg->error = JPEG_DUPLICATE_COMPONENT_ID;
return false;
}
ids_seen[id] = true;
jpg->components[i].id = id;
int factor = ReadUint8(data, pos);
int h_samp_factor = factor >> 4;
int v_samp_factor = factor & 0xf;
VERIFY_INPUT(h_samp_factor, 1, 15, SAMP_FACTOR);
VERIFY_INPUT(v_samp_factor, 1, 15, SAMP_FACTOR);
jpg->components[i].h_samp_factor = h_samp_factor;
jpg->components[i].v_samp_factor = v_samp_factor;
jpg->components[i].quant_idx = ReadUint8(data, pos);
jpg->max_h_samp_factor = std::max(jpg->max_h_samp_factor, h_samp_factor);
jpg->max_v_samp_factor = std::max(jpg->max_v_samp_factor, v_samp_factor);
}
// We have checked above that none of the sampling factors are 0, so the max
// sampling factors can not be 0.
jpg->MCU_rows = DivCeil(jpg->height, jpg->max_v_samp_factor * 8);
jpg->MCU_cols = DivCeil(jpg->width, jpg->max_h_samp_factor * 8);
// Compute the block dimensions for each component.
if (mode == JPEG_READ_ALL) {
for (size_t i = 0; i < jpg->components.size(); ++i) {
JPEGComponent* c = &jpg->components[i];
if (jpg->max_h_samp_factor % c->h_samp_factor != 0 ||
jpg->max_v_samp_factor % c->v_samp_factor != 0) {
fprintf(stderr, "Non-integral subsampling ratios.\n");
jpg->error = JPEG_INVALID_SAMPLING_FACTORS;
return false;
}
c->width_in_blocks = jpg->MCU_cols * c->h_samp_factor;
c->height_in_blocks = jpg->MCU_rows * c->v_samp_factor;
const uint64_t num_blocks =
static_cast(c->width_in_blocks) * c->height_in_blocks;
if (num_blocks > (1ull << 21)) {
// Refuse to allocate more than 1 GB of memory for the coefficients,
// that is 2M blocks x 64 coeffs x 2 bytes per coeff x max 4 components.
// TODO(user) Add this limit to a GuetzliParams struct.
fprintf(stderr, "Image too large.\n");
jpg->error = JPEG_IMAGE_TOO_LARGE;
return false;
}
c->num_blocks = static_cast(num_blocks);
c->coeffs.resize(c->num_blocks * kDCTBlockSize);
}
}
VERIFY_MARKER_END();
return true;
}
// Reads the Start of Scan (SOS) marker segment and fills in *scan_info with the
// parsed data.
bool ProcessSOS(const uint8_t* data, const size_t len, size_t* pos,
JPEGData* jpg) {
const size_t start_pos = *pos;
VERIFY_LEN(3);
size_t marker_len = ReadUint16(data, pos);
int comps_in_scan = ReadUint8(data, pos);
VERIFY_INPUT(comps_in_scan, 1, static_cast(jpg->components.size()),
COMPS_IN_SCAN);
JPEGScanInfo scan_info;
scan_info.components.resize(comps_in_scan);
VERIFY_LEN(2 * comps_in_scan);
std::vector ids_seen(256, false);
for (int i = 0; i < comps_in_scan; ++i) {
int id = ReadUint8(data, pos);
if (ids_seen[id]) { // (cf. section B.2.3, regarding CSj)
fprintf(stderr, "Duplicate ID %d in SOS.\n", id);
jpg->error = JPEG_DUPLICATE_COMPONENT_ID;
return false;
}
ids_seen[id] = true;
bool found_index = false;
for (size_t j = 0; j < jpg->components.size(); ++j) {
if (jpg->components[j].id == id) {
scan_info.components[i].comp_idx = j;
found_index = true;
}
}
if (!found_index) {
fprintf(stderr, "SOS marker: Could not find component with id %d\n", id);
jpg->error = JPEG_COMPONENT_NOT_FOUND;
return false;
}
int c = ReadUint8(data, pos);
int dc_tbl_idx = c >> 4;
int ac_tbl_idx = c & 0xf;
VERIFY_INPUT(dc_tbl_idx, 0, 3, HUFFMAN_INDEX);
VERIFY_INPUT(ac_tbl_idx, 0, 3, HUFFMAN_INDEX);
scan_info.components[i].dc_tbl_idx = dc_tbl_idx;
scan_info.components[i].ac_tbl_idx = ac_tbl_idx;
}
VERIFY_LEN(3);
scan_info.Ss = ReadUint8(data, pos);
scan_info.Se = ReadUint8(data, pos);
VERIFY_INPUT(scan_info.Ss, 0, 63, START_OF_SCAN);
VERIFY_INPUT(scan_info.Se, scan_info.Ss, 63, END_OF_SCAN);
int c = ReadUint8(data, pos);
scan_info.Ah = c >> 4;
scan_info.Al = c & 0xf;
// Check that all the Huffman tables needed for this scan are defined.
for (int i = 0; i < comps_in_scan; ++i) {
bool found_dc_table = false;
bool found_ac_table = false;
for (size_t j = 0; j < jpg->huffman_code.size(); ++j) {
int slot_id = jpg->huffman_code[j].slot_id;
if (slot_id == scan_info.components[i].dc_tbl_idx) {
found_dc_table = true;
} else if (slot_id == scan_info.components[i].ac_tbl_idx + 16) {
found_ac_table = true;
}
}
if (scan_info.Ss == 0 && !found_dc_table) {
fprintf(stderr, "SOS marker: Could not find DC Huffman table with index "
"%d\n", scan_info.components[i].dc_tbl_idx);
jpg->error = JPEG_HUFFMAN_TABLE_NOT_FOUND;
return false;
}
if (scan_info.Se > 0 && !found_ac_table) {
fprintf(stderr, "SOS marker: Could not find AC Huffman table with index "
"%d\n", scan_info.components[i].ac_tbl_idx);
jpg->error = JPEG_HUFFMAN_TABLE_NOT_FOUND;
return false;
}
}
jpg->scan_info.push_back(scan_info);
VERIFY_MARKER_END();
return true;
}
// Reads the Define Huffman Table (DHT) marker segment and fills in *jpg with
// the parsed data. Builds the Huffman decoding table in either dc_huff_lut or
// ac_huff_lut, depending on the type and solt_id of Huffman code being read.
bool ProcessDHT(const uint8_t* data, const size_t len,
JpegReadMode mode,
std::vector* dc_huff_lut,
std::vector* ac_huff_lut,
size_t* pos,
JPEGData* jpg) {
const size_t start_pos = *pos;
VERIFY_LEN(2);
size_t marker_len = ReadUint16(data, pos);
if (marker_len == 2) {
fprintf(stderr, "DHT marker: no Huffman table found\n");
jpg->error = JPEG_EMPTY_DHT;
return false;
}
while (*pos < start_pos + marker_len) {
VERIFY_LEN(1 + kJpegHuffmanMaxBitLength);
JPEGHuffmanCode huff;
huff.slot_id = ReadUint8(data, pos);
int huffman_index = huff.slot_id;
int is_ac_table = (huff.slot_id & 0x10) != 0;
HuffmanTableEntry* huff_lut;
if (is_ac_table) {
huffman_index -= 0x10;
VERIFY_INPUT(huffman_index, 0, 3, HUFFMAN_INDEX);
huff_lut = &(*ac_huff_lut)[huffman_index * kJpegHuffmanLutSize];
} else {
VERIFY_INPUT(huffman_index, 0, 3, HUFFMAN_INDEX);
huff_lut = &(*dc_huff_lut)[huffman_index * kJpegHuffmanLutSize];
}
huff.counts[0] = 0;
int total_count = 0;
int space = 1 << kJpegHuffmanMaxBitLength;
int max_depth = 1;
for (int i = 1; i <= kJpegHuffmanMaxBitLength; ++i) {
int count = ReadUint8(data, pos);
if (count != 0) {
max_depth = i;
}
huff.counts[i] = count;
total_count += count;
space -= count * (1 << (kJpegHuffmanMaxBitLength - i));
}
if (is_ac_table) {
VERIFY_INPUT(total_count, 0, kJpegHuffmanAlphabetSize, HUFFMAN_CODE);
} else {
VERIFY_INPUT(total_count, 0, kJpegDCAlphabetSize, HUFFMAN_CODE);
}
VERIFY_LEN(total_count);
std::vector values_seen(256, false);
for (int i = 0; i < total_count; ++i) {
uint8_t value = ReadUint8(data, pos);
if (!is_ac_table) {
VERIFY_INPUT(value, 0, kJpegDCAlphabetSize - 1, HUFFMAN_CODE);
}
if (values_seen[value]) {
fprintf(stderr, "Duplicate Huffman code value %d\n", value);
jpg->error = JPEG_INVALID_HUFFMAN_CODE;
return false;
}
values_seen[value] = true;
huff.values[i] = value;
}
// Add an invalid symbol that will have the all 1 code.
++huff.counts[max_depth];
huff.values[total_count] = kJpegHuffmanAlphabetSize;
space -= (1 << (kJpegHuffmanMaxBitLength - max_depth));
if (space < 0) {
fprintf(stderr, "Invalid Huffman code lengths.\n");
jpg->error = JPEG_INVALID_HUFFMAN_CODE;
return false;
} else if (space > 0 && huff_lut[0].value != 0xffff) {
// Re-initialize the values to an invalid symbol so that we can recognize
// it when reading the bit stream using a Huffman code with space > 0.
for (int i = 0; i < kJpegHuffmanLutSize; ++i) {
huff_lut[i].bits = 0;
huff_lut[i].value = 0xffff;
}
}
huff.is_last = (*pos == start_pos + marker_len);
if (mode == JPEG_READ_ALL &&
!BuildJpegHuffmanTable(&huff.counts[0], &huff.values[0], huff_lut)) {
fprintf(stderr, "Failed to build Huffman table.\n");
jpg->error = JPEG_INVALID_HUFFMAN_CODE;
return false;
}
jpg->huffman_code.push_back(huff);
}
VERIFY_MARKER_END();
return true;
}
// Reads the Define Quantization Table (DQT) marker segment and fills in *jpg
// with the parsed data.
bool ProcessDQT(const uint8_t* data, const size_t len, size_t* pos,
JPEGData* jpg) {
const size_t start_pos = *pos;
VERIFY_LEN(2);
size_t marker_len = ReadUint16(data, pos);
if (marker_len == 2) {
fprintf(stderr, "DQT marker: no quantization table found\n");
jpg->error = JPEG_EMPTY_DQT;
return false;
}
while (*pos < start_pos + marker_len && jpg->quant.size() < kMaxQuantTables) {
VERIFY_LEN(1);
int quant_table_index = ReadUint8(data, pos);
int quant_table_precision = quant_table_index >> 4;
quant_table_index &= 0xf;
VERIFY_INPUT(quant_table_index, 0, 3, QUANT_TBL_INDEX);
VERIFY_LEN((quant_table_precision ? 2 : 1) * kDCTBlockSize);
JPEGQuantTable table;
table.index = quant_table_index;
table.precision = quant_table_precision;
for (int i = 0; i < kDCTBlockSize; ++i) {
int quant_val = quant_table_precision ?
ReadUint16(data, pos) :
ReadUint8(data, pos);
VERIFY_INPUT(quant_val, 1, 65535, QUANT_VAL);
table.values[kJPEGNaturalOrder[i]] = quant_val;
}
table.is_last = (*pos == start_pos + marker_len);
jpg->quant.push_back(table);
}
VERIFY_MARKER_END();
return true;
}
// Reads the DRI marker and saved the restart interval into *jpg.
bool ProcessDRI(const uint8_t* data, const size_t len, size_t* pos,
JPEGData* jpg) {
if (jpg->restart_interval > 0) {
fprintf(stderr, "Duplicate DRI marker.\n");
jpg->error = JPEG_DUPLICATE_DRI;
return false;
}
const size_t start_pos = *pos;
VERIFY_LEN(4);
size_t marker_len = ReadUint16(data, pos);
int restart_interval = ReadUint16(data, pos);
jpg->restart_interval = restart_interval;
VERIFY_MARKER_END();
return true;
}
// Saves the APP marker segment as a string to *jpg.
bool ProcessAPP(const uint8_t* data, const size_t len, size_t* pos,
JPEGData* jpg) {
VERIFY_LEN(2);
size_t marker_len = ReadUint16(data, pos);
VERIFY_INPUT(marker_len, 2, 65535, MARKER_LEN);
VERIFY_LEN(marker_len - 2);
// Save the marker type together with the app data.
std::string app_str(reinterpret_cast(
&data[*pos - 3]), marker_len + 1);
*pos += marker_len - 2;
jpg->app_data.push_back(app_str);
return true;
}
// Saves the COM marker segment as a string to *jpg.
bool ProcessCOM(const uint8_t* data, const size_t len, size_t* pos,
JPEGData* jpg) {
VERIFY_LEN(2);
size_t marker_len = ReadUint16(data, pos);
VERIFY_INPUT(marker_len, 2, 65535, MARKER_LEN);
VERIFY_LEN(marker_len - 2);
std::string com_str(reinterpret_cast(
&data[*pos - 2]), marker_len);
*pos += marker_len - 2;
jpg->com_data.push_back(com_str);
return true;
}
// Helper structure to read bits from the entropy coded data segment.
struct BitReaderState {
BitReaderState(const uint8_t* data, const size_t len, size_t pos)
: data_(data), len_(len) {
Reset(pos);
}
void Reset(size_t pos) {
pos_ = pos;
val_ = 0;
bits_left_ = 0;
next_marker_pos_ = len_ - 2;
FillBitWindow();
}
// Returns the next byte and skips the 0xff/0x00 escape sequences.
uint8_t GetNextByte() {
if (pos_ >= next_marker_pos_) {
++pos_;
return 0;
}
uint8_t c = data_[pos_++];
if (c == 0xff) {
uint8_t escape = data_[pos_];
if (escape == 0) {
++pos_;
} else {
// 0xff was followed by a non-zero byte, which means that we found the
// start of the next marker segment.
next_marker_pos_ = pos_ - 1;
}
}
return c;
}
void FillBitWindow() {
if (bits_left_ <= 16) {
while (bits_left_ <= 56) {
val_ <<= 8;
val_ |= (uint64_t)GetNextByte();
bits_left_ += 8;
}
}
}
int ReadBits(int nbits) {
FillBitWindow();
uint64_t val = (val_ >> (bits_left_ - nbits)) & ((1ULL << nbits) - 1);
bits_left_ -= nbits;
return val;
}
// Sets *pos to the next stream position where parsing should continue.
// Returns false if the stream ended too early.
bool FinishStream(size_t* pos) {
// Give back some bytes that we did not use.
int unused_bytes_left = bits_left_ >> 3;
while (unused_bytes_left-- > 0) {
--pos_;
// If we give back a 0 byte, we need to check if it was a 0xff/0x00 escape
// sequence, and if yes, we need to give back one more byte.
if (pos_ < next_marker_pos_ &&
data_[pos_] == 0 && data_[pos_ - 1] == 0xff) {
--pos_;
}
}
if (pos_ > next_marker_pos_) {
// Data ran out before the scan was complete.
fprintf(stderr, "Unexpected end of scan.\n");
return false;
}
*pos = pos_;
return true;
}
const uint8_t* data_;
const size_t len_;
size_t pos_;
uint64_t val_;
int bits_left_;
size_t next_marker_pos_;
};
// Returns the next Huffman-coded symbol.
int ReadSymbol(const HuffmanTableEntry* table, BitReaderState* br) {
int nbits;
br->FillBitWindow();
int val = (br->val_ >> (br->bits_left_ - 8)) & 0xff;
table += val;
nbits = table->bits - 8;
if (nbits > 0) {
br->bits_left_ -= 8;
table += table->value;
val = (br->val_ >> (br->bits_left_ - nbits)) & ((1 << nbits) - 1);
table += val;
}
br->bits_left_ -= table->bits;
return table->value;
}
// Returns the DC diff or AC value for extra bits value x and prefix code s.
// See Tables F.1 and F.2 of the spec.
int HuffExtend(int x, int s) {
return (x < (1 << (s - 1)) ? x - (1 << s) + 1 : x);
}
// Decodes one 8x8 block of DCT coefficients from the bit stream.
bool DecodeDCTBlock(const HuffmanTableEntry* dc_huff,
const HuffmanTableEntry* ac_huff,
int Ss, int Se, int Al,
int* eobrun,
BitReaderState* br,
JPEGData* jpg,
coeff_t* last_dc_coeff,
coeff_t* coeffs) {
int s;
int r;
bool eobrun_allowed = Ss > 0;
if (Ss == 0) {
s = ReadSymbol(dc_huff, br);
if (s >= kJpegDCAlphabetSize) {
fprintf(stderr, "Invalid Huffman symbol %d for DC coefficient.\n", s);
jpg->error = JPEG_INVALID_SYMBOL;
return false;
}
if (s > 0) {
r = br->ReadBits(s);
s = HuffExtend(r, s);
}
s += *last_dc_coeff;
const int dc_coeff = SignedLeftshift(s, Al);
coeffs[0] = dc_coeff;
if (dc_coeff != coeffs[0]) {
fprintf(stderr, "Invalid DC coefficient %d\n", dc_coeff);
jpg->error = JPEG_NON_REPRESENTABLE_DC_COEFF;
return false;
}
*last_dc_coeff = s;
++Ss;
}
if (Ss > Se) {
return true;
}
if (*eobrun > 0) {
--(*eobrun);
return true;
}
for (int k = Ss; k <= Se; k++) {
s = ReadSymbol(ac_huff, br);
if (s >= kJpegHuffmanAlphabetSize) {
fprintf(stderr, "Invalid Huffman symbol %d for AC coefficient %d\n",
s, k);
jpg->error = JPEG_INVALID_SYMBOL;
return false;
}
r = s >> 4;
s &= 15;
if (s > 0) {
k += r;
if (k > Se) {
fprintf(stderr, "Out-of-band coefficient %d band was %d-%d\n",
k, Ss, Se);
jpg->error = JPEG_OUT_OF_BAND_COEFF;
return false;
}
if (s + Al >= kJpegDCAlphabetSize) {
fprintf(stderr, "Out of range AC coefficient value: s=%d Al=%d k=%d\n",
s, Al, k);
jpg->error = JPEG_NON_REPRESENTABLE_AC_COEFF;
return false;
}
r = br->ReadBits(s);
s = HuffExtend(r, s);
coeffs[kJPEGNaturalOrder[k]] = SignedLeftshift(s, Al);
} else if (r == 15) {
k += 15;
} else {
*eobrun = 1 << r;
if (r > 0) {
if (!eobrun_allowed) {
fprintf(stderr, "End-of-block run crossing DC coeff.\n");
jpg->error = JPEG_EOB_RUN_TOO_LONG;
return false;
}
*eobrun += br->ReadBits(r);
}
break;
}
}
--(*eobrun);
return true;
}
bool RefineDCTBlock(const HuffmanTableEntry* ac_huff,
int Ss, int Se, int Al,
int* eobrun,
BitReaderState* br,
JPEGData* jpg,
coeff_t* coeffs) {
bool eobrun_allowed = Ss > 0;
if (Ss == 0) {
int s = br->ReadBits(1);
coeff_t dc_coeff = coeffs[0];
dc_coeff |= s << Al;
coeffs[0] = dc_coeff;
++Ss;
}
if (Ss > Se) {
return true;
}
int p1 = 1 << Al;
int m1 = -(1 << Al);
int k = Ss;
int r;
int s;
bool in_zero_run = false;
if (*eobrun <= 0) {
for (; k <= Se; k++) {
s = ReadSymbol(ac_huff, br);
if (s >= kJpegHuffmanAlphabetSize) {
fprintf(stderr, "Invalid Huffman symbol %d for AC coefficient %d\n",
s, k);
jpg->error = JPEG_INVALID_SYMBOL;
return false;
}
r = s >> 4;
s &= 15;
if (s) {
if (s != 1) {
fprintf(stderr, "Invalid Huffman symbol %d for AC coefficient %d\n",
s, k);
jpg->error = JPEG_INVALID_SYMBOL;
return false;
}
s = br->ReadBits(1) ? p1 : m1;
in_zero_run = false;
} else {
if (r != 15) {
*eobrun = 1 << r;
if (r > 0) {
if (!eobrun_allowed) {
fprintf(stderr, "End-of-block run crossing DC coeff.\n");
jpg->error = JPEG_EOB_RUN_TOO_LONG;
return false;
}
*eobrun += br->ReadBits(r);
}
break;
}
in_zero_run = true;
}
do {
coeff_t thiscoef = coeffs[kJPEGNaturalOrder[k]];
if (thiscoef != 0) {
if (br->ReadBits(1)) {
if ((thiscoef & p1) == 0) {
if (thiscoef >= 0) {
thiscoef += p1;
} else {
thiscoef += m1;
}
}
}
coeffs[kJPEGNaturalOrder[k]] = thiscoef;
} else {
if (--r < 0) {
break;
}
}
k++;
} while (k <= Se);
if (s) {
if (k > Se) {
fprintf(stderr, "Out-of-band coefficient %d band was %d-%d\n",
k, Ss, Se);
jpg->error = JPEG_OUT_OF_BAND_COEFF;
return false;
}
coeffs[kJPEGNaturalOrder[k]] = s;
}
}
}
if (in_zero_run) {
fprintf(stderr, "Extra zero run before end-of-block.\n");
jpg->error = JPEG_EXTRA_ZERO_RUN;
return false;
}
if (*eobrun > 0) {
for (; k <= Se; k++) {
coeff_t thiscoef = coeffs[kJPEGNaturalOrder[k]];
if (thiscoef != 0) {
if (br->ReadBits(1)) {
if ((thiscoef & p1) == 0) {
if (thiscoef >= 0) {
thiscoef += p1;
} else {
thiscoef += m1;
}
}
}
coeffs[kJPEGNaturalOrder[k]] = thiscoef;
}
}
}
--(*eobrun);
return true;
}
bool ProcessRestart(const uint8_t* data, const size_t len,
int* next_restart_marker, BitReaderState* br,
JPEGData* jpg) {
size_t pos = 0;
if (!br->FinishStream(&pos)) {
jpg->error = JPEG_INVALID_SCAN;
return false;
}
int expected_marker = 0xd0 + *next_restart_marker;
EXPECT_MARKER();
int marker = data[pos + 1];
if (marker != expected_marker) {
fprintf(stderr, "Did not find expected restart marker %d actual=%d\n",
expected_marker, marker);
jpg->error = JPEG_WRONG_RESTART_MARKER;
return false;
}
br->Reset(pos + 2);
*next_restart_marker += 1;
*next_restart_marker &= 0x7;
return true;
}
bool ProcessScan(const uint8_t* data, const size_t len,
const std::vector& dc_huff_lut,
const std::vector& ac_huff_lut,
uint16_t scan_progression[kMaxComponents][kDCTBlockSize],
bool is_progressive,
size_t* pos,
JPEGData* jpg) {
if (!ProcessSOS(data, len, pos, jpg)) {
return false;
}
JPEGScanInfo* scan_info = &jpg->scan_info.back();
bool is_interleaved = (scan_info->components.size() > 1);
int MCUs_per_row;
int MCU_rows;
if (is_interleaved) {
MCUs_per_row = jpg->MCU_cols;
MCU_rows = jpg->MCU_rows;
} else {
const JPEGComponent& c = jpg->components[scan_info->components[0].comp_idx];
MCUs_per_row =
DivCeil(jpg->width * c.h_samp_factor, 8 * jpg->max_h_samp_factor);
MCU_rows =
DivCeil(jpg->height * c.v_samp_factor, 8 * jpg->max_v_samp_factor);
}
coeff_t last_dc_coeff[kMaxComponents] = {0};
BitReaderState br(data, len, *pos);
int restarts_to_go = jpg->restart_interval;
int next_restart_marker = 0;
int eobrun = -1;
int block_scan_index = 0;
const int Al = is_progressive ? scan_info->Al : 0;
const int Ah = is_progressive ? scan_info->Ah : 0;
const int Ss = is_progressive ? scan_info->Ss : 0;
const int Se = is_progressive ? scan_info->Se : 63;
const uint16_t scan_bitmask = Ah == 0 ? (0xffff << Al) : (1u << Al);
const uint16_t refinement_bitmask = (1 << Al) - 1;
for (size_t i = 0; i < scan_info->components.size(); ++i) {
int comp_idx = scan_info->components[i].comp_idx;
for (int k = Ss; k <= Se; ++k) {
if (scan_progression[comp_idx][k] & scan_bitmask) {
fprintf(stderr, "Overlapping scans: component=%d k=%d prev_mask=%d "
"cur_mask=%d\n", comp_idx, k, scan_progression[i][k],
scan_bitmask);
jpg->error = JPEG_OVERLAPPING_SCANS;
return false;
}
if (scan_progression[comp_idx][k] & refinement_bitmask) {
fprintf(stderr, "Invalid scan order, a more refined scan was already "
"done: component=%d k=%d prev_mask=%d cur_mask=%d\n", comp_idx,
k, scan_progression[i][k], scan_bitmask);
jpg->error = JPEG_INVALID_SCAN_ORDER;
return false;
}
scan_progression[comp_idx][k] |= scan_bitmask;
}
}
if (Al > 10) {
fprintf(stderr, "Scan parameter Al=%d is not supported in guetzli.\n", Al);
jpg->error = JPEG_NON_REPRESENTABLE_AC_COEFF;
return false;
}
for (int mcu_y = 0; mcu_y < MCU_rows; ++mcu_y) {
for (int mcu_x = 0; mcu_x < MCUs_per_row; ++mcu_x) {
// Handle the restart intervals.
if (jpg->restart_interval > 0) {
if (restarts_to_go == 0) {
if (ProcessRestart(data, len,
&next_restart_marker, &br, jpg)) {
restarts_to_go = jpg->restart_interval;
memset(last_dc_coeff, 0, sizeof(last_dc_coeff));
if (eobrun > 0) {
fprintf(stderr, "End-of-block run too long.\n");
jpg->error = JPEG_EOB_RUN_TOO_LONG;
return false;
}
eobrun = -1; // fresh start
} else {
return false;
}
}
--restarts_to_go;
}
// Decode one MCU.
for (size_t i = 0; i < scan_info->components.size(); ++i) {
JPEGComponentScanInfo* si = &scan_info->components[i];
JPEGComponent* c = &jpg->components[si->comp_idx];
const HuffmanTableEntry* dc_lut =
&dc_huff_lut[si->dc_tbl_idx * kJpegHuffmanLutSize];
const HuffmanTableEntry* ac_lut =
&ac_huff_lut[si->ac_tbl_idx * kJpegHuffmanLutSize];
int nblocks_y = is_interleaved ? c->v_samp_factor : 1;
int nblocks_x = is_interleaved ? c->h_samp_factor : 1;
for (int iy = 0; iy < nblocks_y; ++iy) {
for (int ix = 0; ix < nblocks_x; ++ix) {
int block_y = mcu_y * nblocks_y + iy;
int block_x = mcu_x * nblocks_x + ix;
int block_idx = block_y * c->width_in_blocks + block_x;
coeff_t* coeffs = &c->coeffs[block_idx * kDCTBlockSize];
if (Ah == 0) {
if (!DecodeDCTBlock(dc_lut, ac_lut, Ss, Se, Al, &eobrun, &br, jpg,
&last_dc_coeff[si->comp_idx], coeffs)) {
return false;
}
} else {
if (!RefineDCTBlock(ac_lut, Ss, Se, Al,
&eobrun, &br, jpg, coeffs)) {
return false;
}
}
++block_scan_index;
}
}
}
}
}
if (eobrun > 0) {
fprintf(stderr, "End-of-block run too long.\n");
jpg->error = JPEG_EOB_RUN_TOO_LONG;
return false;
}
if (!br.FinishStream(pos)) {
jpg->error = JPEG_INVALID_SCAN;
return false;
}
if (*pos > len) {
fprintf(stderr, "Unexpected end of file during scan. pos=%d len=%d\n",
static_cast(*pos), static_cast(len));
jpg->error = JPEG_UNEXPECTED_EOF;
return false;
}
return true;
}
// Changes the quant_idx field of the components to refer to the index of the
// quant table in the jpg->quant array.
bool FixupIndexes(JPEGData* jpg) {
for (size_t i = 0; i < jpg->components.size(); ++i) {
JPEGComponent* c = &jpg->components[i];
bool found_index = false;
for (size_t j = 0; j < jpg->quant.size(); ++j) {
if (jpg->quant[j].index == c->quant_idx) {
c->quant_idx = j;
found_index = true;
break;
}
}
if (!found_index) {
fprintf(stderr, "Quantization table with index %zd not found\n",
c->quant_idx);
jpg->error = JPEG_QUANT_TABLE_NOT_FOUND;
return false;
}
}
return true;
}
size_t FindNextMarker(const uint8_t* data, const size_t len, size_t pos) {
// kIsValidMarker[i] == 1 means (0xc0 + i) is a valid marker.
static const uint8_t kIsValidMarker[] = {
1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0,
};
size_t num_skipped = 0;
while (pos + 1 < len &&
(data[pos] != 0xff || data[pos + 1] < 0xc0 ||
!kIsValidMarker[data[pos + 1] - 0xc0])) {
++pos;
++num_skipped;
}
return num_skipped;
}
} // namespace
bool ReadJpeg(const uint8_t* data, const size_t len, JpegReadMode mode,
JPEGData* jpg) {
size_t pos = 0;
// Check SOI marker.
EXPECT_MARKER();
int marker = data[pos + 1];
pos += 2;
if (marker != 0xd8) {
fprintf(stderr, "Did not find expected SOI marker, actual=%d\n", marker);
jpg->error = JPEG_SOI_NOT_FOUND;
return false;
}
int lut_size = kMaxHuffmanTables * kJpegHuffmanLutSize;
std::vector dc_huff_lut(lut_size);
std::vector ac_huff_lut(lut_size);
bool found_sof = false;
uint16_t scan_progression[kMaxComponents][kDCTBlockSize] = { { 0 } };
bool is_progressive = false; // default
do {
// Read next marker.
size_t num_skipped = FindNextMarker(data, len, pos);
if (num_skipped > 0) {
// Add a fake marker to indicate arbitrary in-between-markers data.
jpg->marker_order.push_back(0xff);
jpg->inter_marker_data.push_back(
std::string(reinterpret_cast(&data[pos]),
num_skipped));
pos += num_skipped;
}
EXPECT_MARKER();
marker = data[pos + 1];
pos += 2;
bool ok = true;
switch (marker) {
case 0xc0:
case 0xc1:
case 0xc2:
is_progressive = (marker == 0xc2);
ok = ProcessSOF(data, len, mode, &pos, jpg);
found_sof = true;
break;
case 0xc4:
ok = ProcessDHT(data, len, mode, &dc_huff_lut, &ac_huff_lut, &pos, jpg);
break;
case 0xd0:
case 0xd1:
case 0xd2:
case 0xd3:
case 0xd4:
case 0xd5:
case 0xd6:
case 0xd7:
// RST markers do not have any data.
break;
case 0xd9:
// Found end marker.
break;
case 0xda:
if (mode == JPEG_READ_ALL) {
ok = ProcessScan(data, len, dc_huff_lut, ac_huff_lut,
scan_progression, is_progressive, &pos, jpg);
}
break;
case 0xdb:
ok = ProcessDQT(data, len, &pos, jpg);
break;
case 0xdd:
ok = ProcessDRI(data, len, &pos, jpg);
break;
case 0xe0:
case 0xe1:
case 0xe2:
case 0xe3:
case 0xe4:
case 0xe5:
case 0xe6:
case 0xe7:
case 0xe8:
case 0xe9:
case 0xea:
case 0xeb:
case 0xec:
case 0xed:
case 0xee:
case 0xef:
if (mode != JPEG_READ_TABLES) {
ok = ProcessAPP(data, len, &pos, jpg);
}
break;
case 0xfe:
if (mode != JPEG_READ_TABLES) {
ok = ProcessCOM(data, len, &pos, jpg);
}
break;
default:
fprintf(stderr, "Unsupported marker: %d pos=%d len=%d\n",
marker, static_cast(pos), static_cast(len));
jpg->error = JPEG_UNSUPPORTED_MARKER;
ok = false;
break;
}
if (!ok) {
return false;
}
jpg->marker_order.push_back(marker);
if (mode == JPEG_READ_HEADER && found_sof) {
break;
}
} while (marker != 0xd9);
if (!found_sof) {
fprintf(stderr, "Missing SOF marker.\n");
jpg->error = JPEG_SOF_NOT_FOUND;
return false;
}
// Supplemental checks.
if (mode == JPEG_READ_ALL) {
if (pos < len) {
jpg->tail_data.assign(reinterpret_cast(&data[pos]),
len - pos);
}
if (!FixupIndexes(jpg)) {
return false;
}
if (jpg->huffman_code.size() == 0) {
// Section B.2.4.2: "If a table has never been defined for a particular
// destination, then when this destination is specified in a scan header,
// the results are unpredictable."
fprintf(stderr, "Need at least one Huffman code table.\n");
jpg->error = JPEG_HUFFMAN_TABLE_ERROR;
return false;
}
if (jpg->huffman_code.size() >= kMaxDHTMarkers) {
fprintf(stderr, "Too many Huffman tables.\n");
jpg->error = JPEG_HUFFMAN_TABLE_ERROR;
return false;
}
}
return true;
}
bool ReadJpeg(const std::string& data, JpegReadMode mode,
JPEGData* jpg) {
return ReadJpeg(reinterpret_cast(data.data()),
static_cast(data.size()),
mode, jpg);
}
} // namespace guetzli
================================================
FILE: guetzli/jpeg_data_reader.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Functions for reading a jpeg byte stream into a JPEGData object.
#ifndef GUETZLI_JPEG_DATA_READER_H_
#define GUETZLI_JPEG_DATA_READER_H_
#include
#include
#include
#include "guetzli/jpeg_data.h"
namespace guetzli {
enum JpegReadMode {
JPEG_READ_HEADER, // only basic headers
JPEG_READ_TABLES, // headers and tables (quant, Huffman, ...)
JPEG_READ_ALL, // everything
};
// Parses the jpeg stream contained in data[*pos ... len) and fills in *jpg with
// the parsed information.
// If mode is JPEG_READ_HEADER, it fills in only the image dimensions in *jpg.
// Returns false if the data is not valid jpeg, or if it contains an unsupported
// jpeg feature.
bool ReadJpeg(const uint8_t* data, const size_t len, JpegReadMode mode,
JPEGData* jpg);
// string variant
bool ReadJpeg(const std::string& data, JpegReadMode mode,
JPEGData* jpg);
} // namespace guetzli
#endif // GUETZLI_JPEG_DATA_READER_H_
================================================
FILE: guetzli/jpeg_data_writer.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/jpeg_data_writer.h"
#include
#include
#include
#include "guetzli/entropy_encode.h"
#include "guetzli/fast_log.h"
#include "guetzli/jpeg_bit_writer.h"
namespace guetzli {
namespace {
static const int kJpegPrecision = 8;
// Writes len bytes from buf, using the out callback.
inline bool JPEGWrite(JPEGOutput out, const uint8_t* buf, size_t len) {
static const size_t kBlockSize = 1u << 30;
size_t pos = 0;
while (len - pos > kBlockSize) {
if (!out.Write(buf + pos, kBlockSize)) {
return false;
}
pos += kBlockSize;
}
return out.Write(buf + pos, len - pos);
}
// Writes a string using the out callback.
inline bool JPEGWrite(JPEGOutput out, const std::string& s) {
const uint8_t* data = reinterpret_cast(&s[0]);
return JPEGWrite(out, data, s.size());
}
bool EncodeMetadata(const JPEGData& jpg, bool strip_metadata, JPEGOutput out) {
if (strip_metadata) {
const uint8_t kApp0Data[] = {
0xff, 0xe0, 0x00, 0x10, // APP0
0x4a, 0x46, 0x49, 0x46, 0x00, // 'JFIF'
0x01, 0x01, // v1.01
0x00, 0x00, 0x01, 0x00, 0x01, // aspect ratio = 1:1
0x00, 0x00 // thumbnail width/height
};
return JPEGWrite(out, kApp0Data, sizeof(kApp0Data));
}
bool ok = true;
for (size_t i = 0; i < jpg.app_data.size(); ++i) {
uint8_t data[1] = { 0xff };
ok = ok && JPEGWrite(out, data, sizeof(data));
ok = ok && JPEGWrite(out, jpg.app_data[i]);
}
for (size_t i = 0; i < jpg.com_data.size(); ++i) {
uint8_t data[2] = { 0xff, 0xfe };
ok = ok && JPEGWrite(out, data, sizeof(data));
ok = ok && JPEGWrite(out, jpg.com_data[i]);
}
return ok;
}
bool EncodeDQT(const std::vector& quant, JPEGOutput out) {
int marker_len = 2;
for (size_t i = 0; i < quant.size(); ++i) {
marker_len += 1 + (quant[i].precision ? 2 : 1) * kDCTBlockSize;
}
std::vector data(marker_len + 2);
size_t pos = 0;
data[pos++] = 0xff;
data[pos++] = 0xdb;
data[pos++] = marker_len >> 8;
data[pos++] = marker_len & 0xff;
for (size_t i = 0; i < quant.size(); ++i) {
const JPEGQuantTable& table = quant[i];
data[pos++] = (table.precision << 4) + table.index;
for (int k = 0; k < kDCTBlockSize; ++k) {
int val = table.values[kJPEGNaturalOrder[k]];
if (table.precision) {
data[pos++] = val >> 8;
}
data[pos++] = val & 0xff;
}
}
return JPEGWrite(out, &data[0], pos);
}
bool EncodeSOF(const JPEGData& jpg, JPEGOutput out) {
const size_t ncomps = jpg.components.size();
const size_t marker_len = 8 + 3 * ncomps;
std::vector data(marker_len + 2);
size_t pos = 0;
data[pos++] = 0xff;
data[pos++] = 0xc1;
data[pos++] = static_cast(marker_len >> 8);
data[pos++] = marker_len & 0xff;
data[pos++] = kJpegPrecision;
data[pos++] = jpg.height >> 8;
data[pos++] = jpg.height & 0xff;
data[pos++] = jpg.width >> 8;
data[pos++] = jpg.width & 0xff;
data[pos++] = static_cast(ncomps);
for (size_t i = 0; i < ncomps; ++i) {
data[pos++] = jpg.components[i].id;
data[pos++] = ((jpg.components[i].h_samp_factor << 4) |
(jpg.components[i].v_samp_factor));
const size_t quant_idx = jpg.components[i].quant_idx;
if (quant_idx >= jpg.quant.size()) {
return false;
}
data[pos++] = jpg.quant[quant_idx].index;
}
return JPEGWrite(out, &data[0], pos);
}
// Builds a JPEG-style huffman code from the given bit depths.
void BuildHuffmanCode(uint8_t* depth, int* counts, int* values) {
for (int i = 0; i < JpegHistogram::kSize; ++i) {
if (depth[i] > 0) {
++counts[depth[i]];
}
}
int offset[kJpegHuffmanMaxBitLength + 1] = { 0 };
for (int i = 1; i <= kJpegHuffmanMaxBitLength; ++i) {
offset[i] = offset[i - 1] + counts[i - 1];
}
for (int i = 0; i < JpegHistogram::kSize; ++i) {
if (depth[i] > 0) {
values[offset[depth[i]]++] = i;
}
}
}
void BuildHuffmanCodeTable(const int* counts, const int* values,
HuffmanCodeTable* table) {
int huffcode[256];
int huffsize[256];
int p = 0;
for (int l = 1; l <= kJpegHuffmanMaxBitLength; ++l) {
int i = counts[l];
while (i--) huffsize[p++] = l;
}
if (p == 0)
return;
huffsize[p - 1] = 0;
int lastp = p - 1;
int code = 0;
int si = huffsize[0];
p = 0;
while (huffsize[p]) {
while ((huffsize[p]) == si) {
huffcode[p++] = code;
code++;
}
code <<= 1;
si++;
}
for (p = 0; p < lastp; p++) {
int i = values[p];
table->depth[i] = huffsize[p];
table->code[i] = huffcode[p];
}
}
} // namespace
// Updates ac_histogram with the counts of the AC symbols that will be added by
// a sequential jpeg encoder for this block. Every symbol is counted twice so
// that we can add a fake symbol at the end with count 1 to be the last (least
// frequent) symbol with the all 1 code.
void UpdateACHistogramForDCTBlock(const coeff_t* coeffs,
JpegHistogram* ac_histogram) {
int r = 0;
for (int k = 1; k < 64; ++k) {
coeff_t coeff = coeffs[kJPEGNaturalOrder[k]];
if (coeff == 0) {
r++;
continue;
}
while (r > 15) {
ac_histogram->Add(0xf0);
r -= 16;
}
int nbits = Log2FloorNonZero(std::abs(coeff)) + 1;
int symbol = (r << 4) + nbits;
ac_histogram->Add(symbol);
r = 0;
}
if (r > 0) {
ac_histogram->Add(0);
}
}
size_t HistogramHeaderCost(const JpegHistogram& histo) {
size_t header_bits = 17 * 8;
for (int i = 0; i + 1 < JpegHistogram::kSize; ++i) {
if (histo.counts[i] > 0) {
header_bits += 8;
}
}
return header_bits;
}
size_t HistogramEntropyCost(const JpegHistogram& histo,
const uint8_t depths[256]) {
size_t bits = 0;
for (int i = 0; i + 1 < JpegHistogram::kSize; ++i) {
// JpegHistogram::Add() counts every symbol twice, so we have to divide by
// two here.
bits += (histo.counts[i] / 2) * (depths[i] + (i & 0xf));
}
// Estimate escape byte rate to be 0.75/256.
bits += (bits * 3 + 512) >> 10;
return bits;
}
void BuildDCHistograms(const JPEGData& jpg, JpegHistogram* histo) {
for (size_t i = 0; i < jpg.components.size(); ++i) {
const JPEGComponent& c = jpg.components[i];
JpegHistogram* dc_histogram = &histo[i];
coeff_t last_dc_coeff = 0;
for (int mcu_y = 0; mcu_y < jpg.MCU_rows; ++mcu_y) {
for (int mcu_x = 0; mcu_x < jpg.MCU_cols; ++mcu_x) {
for (int iy = 0; iy < c.v_samp_factor; ++iy) {
for (int ix = 0; ix < c.h_samp_factor; ++ix) {
int block_y = mcu_y * c.v_samp_factor + iy;
int block_x = mcu_x * c.h_samp_factor + ix;
int block_idx = block_y * c.width_in_blocks + block_x;
coeff_t dc_coeff = c.coeffs[block_idx << 6];
int diff = std::abs(dc_coeff - last_dc_coeff);
int nbits = Log2Floor(diff) + 1;
dc_histogram->Add(nbits);
last_dc_coeff = dc_coeff;
}
}
}
}
}
}
void BuildACHistograms(const JPEGData& jpg, JpegHistogram* histo) {
for (size_t i = 0; i < jpg.components.size(); ++i) {
const JPEGComponent& c = jpg.components[i];
JpegHistogram* ac_histogram = &histo[i];
for (size_t j = 0; j < c.coeffs.size(); j += kDCTBlockSize) {
UpdateACHistogramForDCTBlock(&c.coeffs[j], ac_histogram);
}
}
}
// Size of everything except the Huffman codes and the entropy coded data.
size_t JpegHeaderSize(const JPEGData& jpg, bool strip_metadata) {
size_t num_bytes = 0;
num_bytes += 2; // SOI
if (strip_metadata) {
num_bytes += 18; // APP0
} else {
for (size_t i = 0; i < jpg.app_data.size(); ++i) {
num_bytes += 1 + jpg.app_data[i].size();
}
for (size_t i = 0; i < jpg.com_data.size(); ++i) {
num_bytes += 2 + jpg.com_data[i].size();
}
}
// DQT
num_bytes += 4;
for (size_t i = 0; i < jpg.quant.size(); ++i) {
num_bytes += 1 + (jpg.quant[i].precision ? 2 : 1) * kDCTBlockSize;
}
num_bytes += 10 + 3 * jpg.components.size(); // SOF
num_bytes += 4; // DHT (w/o actual Huffman code data)
num_bytes += 8 + 2 * jpg.components.size(); // SOS
num_bytes += 2; // EOI
num_bytes += jpg.tail_data.size();
return num_bytes;
}
size_t ClusterHistograms(JpegHistogram* histo, size_t* num,
int* histo_indexes, uint8_t* depth) {
memset(depth, 0, *num * JpegHistogram::kSize);
size_t costs[kMaxComponents];
for (size_t i = 0; i < *num; ++i) {
histo_indexes[i] = i;
std::vector tree(2 * JpegHistogram::kSize + 1);
CreateHuffmanTree(histo[i].counts, JpegHistogram::kSize,
kJpegHuffmanMaxBitLength, &tree[0],
&depth[i * JpegHistogram::kSize]);
costs[i] = (HistogramHeaderCost(histo[i]) +
HistogramEntropyCost(histo[i],
&depth[i * JpegHistogram::kSize]));
}
const size_t orig_num = *num;
while (*num > 1) {
size_t last = *num - 1;
size_t second_last = *num - 2;
JpegHistogram combined(histo[last]);
combined.AddHistogram(histo[second_last]);
std::vector tree(2 * JpegHistogram::kSize + 1);
uint8_t depth_combined[JpegHistogram::kSize] = { 0 };
CreateHuffmanTree(combined.counts, JpegHistogram::kSize,
kJpegHuffmanMaxBitLength, &tree[0], depth_combined);
size_t cost_combined = (HistogramHeaderCost(combined) +
HistogramEntropyCost(combined, depth_combined));
if (cost_combined < costs[last] + costs[second_last]) {
histo[second_last] = combined;
histo[last] = JpegHistogram();
costs[second_last] = cost_combined;
memcpy(&depth[second_last * JpegHistogram::kSize], depth_combined,
sizeof(depth_combined));
for (size_t i = 0; i < orig_num; ++i) {
if (histo_indexes[i] == last) {
histo_indexes[i] = second_last;
}
}
--(*num);
} else {
break;
}
}
size_t total_cost = 0;
for (size_t i = 0; i < *num; ++i) {
total_cost += costs[i];
}
return (total_cost + 7) / 8;
}
size_t EstimateJpegDataSize(const int num_components,
const std::vector& histograms) {
assert(histograms.size() == 2 * num_components);
std::vector clustered = histograms;
size_t num_dc = num_components;
size_t num_ac = num_components;
int indexes[kMaxComponents];
uint8_t depth[kMaxComponents * JpegHistogram::kSize];
return (ClusterHistograms(&clustered[0], &num_dc, indexes, depth) +
ClusterHistograms(&clustered[num_components], &num_ac, indexes,
depth));
}
namespace {
// Writes DHT and SOS marker segments to out and fills in DC/AC Huffman tables
// for each component of the image.
bool BuildAndEncodeHuffmanCodes(const JPEGData& jpg, JPEGOutput out,
std::vector* dc_huff_tables,
std::vector* ac_huff_tables) {
const int ncomps = jpg.components.size();
dc_huff_tables->resize(ncomps);
ac_huff_tables->resize(ncomps);
// Build separate DC histograms for each component.
std::vector histograms(ncomps);
BuildDCHistograms(jpg, &histograms[0]);
// Cluster DC histograms.
size_t num_dc_histo = ncomps;
int dc_histo_indexes[kMaxComponents];
std::vector depths(ncomps * JpegHistogram::kSize);
ClusterHistograms(&histograms[0], &num_dc_histo, dc_histo_indexes,
&depths[0]);
// Build separate AC histograms for each component.
histograms.resize(num_dc_histo + ncomps);
depths.resize((num_dc_histo + ncomps) * JpegHistogram::kSize);
BuildACHistograms(jpg, &histograms[num_dc_histo]);
// Cluster AC histograms.
size_t num_ac_histo = ncomps;
int ac_histo_indexes[kMaxComponents];
ClusterHistograms(&histograms[num_dc_histo], &num_ac_histo, ac_histo_indexes,
&depths[num_dc_histo * JpegHistogram::kSize]);
// Compute DHT and SOS marker data sizes and start emitting DHT marker.
int num_histo = num_dc_histo + num_ac_histo;
histograms.resize(num_histo);
int total_count = 0;
for (size_t i = 0; i < histograms.size(); ++i) {
total_count += histograms[i].NumSymbols();
}
const size_t dht_marker_len =
2 + num_histo * (kJpegHuffmanMaxBitLength + 1) + total_count;
const size_t sos_marker_len = 6 + 2 * ncomps;
std::vector data(dht_marker_len + sos_marker_len + 4);
size_t pos = 0;
data[pos++] = 0xff;
data[pos++] = 0xc4;
data[pos++] = static_cast(dht_marker_len >> 8);
data[pos++] = dht_marker_len & 0xff;
// Compute Huffman codes for each histograms.
for (int i = 0; i < num_histo; ++i) {
const bool is_dc = static_cast(i) < num_dc_histo;
const int idx = is_dc ? i : i - num_dc_histo;
int counts[kJpegHuffmanMaxBitLength + 1] = { 0 };
int values[JpegHistogram::kSize] = { 0 };
BuildHuffmanCode(&depths[i * JpegHistogram::kSize], counts, values);
HuffmanCodeTable table;
for (int j = 0; j < 256; ++j) table.depth[j] = 255;
BuildHuffmanCodeTable(counts, values, &table);
for (int c = 0; c < ncomps; ++c) {
if (is_dc) {
if (dc_histo_indexes[c] == idx) (*dc_huff_tables)[c] = table;
} else {
if (ac_histo_indexes[c] == idx) (*ac_huff_tables)[c] = table;
}
}
int max_length = kJpegHuffmanMaxBitLength;
while (max_length > 0 && counts[max_length] == 0) --max_length;
--counts[max_length];
int total_count = 0;
for (int j = 0; j <= max_length; ++j) total_count += counts[j];
data[pos++] = is_dc ? i : static_cast(i - num_dc_histo + 0x10);
for (size_t j = 1; j <= kJpegHuffmanMaxBitLength; ++j) {
data[pos++] = counts[j];
}
for (int j = 0; j < total_count; ++j) {
data[pos++] = values[j];
}
}
// Emit SOS marker data.
data[pos++] = 0xff;
data[pos++] = 0xda;
data[pos++] = static_cast(sos_marker_len >> 8);
data[pos++] = sos_marker_len & 0xff;
data[pos++] = ncomps;
for (int i = 0; i < ncomps; ++i) {
data[pos++] = jpg.components[i].id;
data[pos++] = (dc_histo_indexes[i] << 4) | ac_histo_indexes[i];
}
data[pos++] = 0;
data[pos++] = 63;
data[pos++] = 0;
assert(pos == data.size());
return JPEGWrite(out, &data[0], data.size());
}
void EncodeDCTBlockSequential(const coeff_t* coeffs,
const HuffmanCodeTable& dc_huff,
const HuffmanCodeTable& ac_huff,
coeff_t* last_dc_coeff,
BitWriter* bw) {
coeff_t temp2;
coeff_t temp;
temp2 = coeffs[0];
temp = temp2 - *last_dc_coeff;
*last_dc_coeff = temp2;
temp2 = temp;
if (temp < 0) {
temp = -temp;
temp2--;
}
int nbits = Log2Floor(temp) + 1;
bw->WriteBits(dc_huff.depth[nbits], dc_huff.code[nbits]);
if (nbits > 0) {
bw->WriteBits(nbits, temp2 & ((1 << nbits) - 1));
}
int r = 0;
for (int k = 1; k < 64; ++k) {
if ((temp = coeffs[kJPEGNaturalOrder[k]]) == 0) {
r++;
continue;
}
if (temp < 0) {
temp = -temp;
temp2 = ~temp;
} else {
temp2 = temp;
}
while (r > 15) {
bw->WriteBits(ac_huff.depth[0xf0], ac_huff.code[0xf0]);
r -= 16;
}
int nbits = Log2FloorNonZero(temp) + 1;
int symbol = (r << 4) + nbits;
bw->WriteBits(ac_huff.depth[symbol], ac_huff.code[symbol]);
bw->WriteBits(nbits, temp2 & ((1 << nbits) - 1));
r = 0;
}
if (r > 0) {
bw->WriteBits(ac_huff.depth[0], ac_huff.code[0]);
}
}
bool EncodeScan(const JPEGData& jpg,
const std::vector& dc_huff_table,
const std::vector& ac_huff_table,
JPEGOutput out) {
coeff_t last_dc_coeff[kMaxComponents] = { 0 };
BitWriter bw(1 << 17);
for (int mcu_y = 0; mcu_y < jpg.MCU_rows; ++mcu_y) {
for (int mcu_x = 0; mcu_x < jpg.MCU_cols; ++mcu_x) {
// Encode one MCU
for (size_t i = 0; i < jpg.components.size(); ++i) {
const JPEGComponent& c = jpg.components[i];
int nblocks_y = c.v_samp_factor;
int nblocks_x = c.h_samp_factor;
for (int iy = 0; iy < nblocks_y; ++iy) {
for (int ix = 0; ix < nblocks_x; ++ix) {
int block_y = mcu_y * nblocks_y + iy;
int block_x = mcu_x * nblocks_x + ix;
int block_idx = block_y * c.width_in_blocks + block_x;
const coeff_t* coeffs = &c.coeffs[block_idx << 6];
EncodeDCTBlockSequential(coeffs, dc_huff_table[i], ac_huff_table[i],
&last_dc_coeff[i], &bw);
}
}
}
if (bw.pos > (1 << 16)) {
if (!JPEGWrite(out, bw.data.get(), bw.pos)) {
return false;
}
bw.pos = 0;
}
}
}
bw.JumpToByteBoundary();
return !bw.overflow && JPEGWrite(out, bw.data.get(), bw.pos);
}
} // namespace
bool WriteJpeg(const JPEGData& jpg, bool strip_metadata, JPEGOutput out) {
static const uint8_t kSOIMarker[2] = { 0xff, 0xd8 };
static const uint8_t kEOIMarker[2] = { 0xff, 0xd9 };
std::vector dc_codes;
std::vector ac_codes;
return (JPEGWrite(out, kSOIMarker, sizeof(kSOIMarker)) &&
EncodeMetadata(jpg, strip_metadata, out) &&
EncodeDQT(jpg.quant, out) &&
EncodeSOF(jpg, out) &&
BuildAndEncodeHuffmanCodes(jpg, out, &dc_codes, &ac_codes) &&
EncodeScan(jpg, dc_codes, ac_codes, out) &&
JPEGWrite(out, kEOIMarker, sizeof(kEOIMarker)) &&
(strip_metadata || JPEGWrite(out, jpg.tail_data)));
}
int NullOut(void* data, const uint8_t* buf, size_t count) {
return count;
}
void BuildSequentialHuffmanCodes(
const JPEGData& jpg,
std::vector* dc_huffman_code_tables,
std::vector* ac_huffman_code_tables) {
JPEGOutput out(NullOut, nullptr);
BuildAndEncodeHuffmanCodes(jpg, out, dc_huffman_code_tables,
ac_huffman_code_tables);
}
} // namespace guetzli
================================================
FILE: guetzli/jpeg_data_writer.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Functions for writing a JPEGData object into a jpeg byte stream.
#ifndef GUETZLI_JPEG_DATA_WRITER_H_
#define GUETZLI_JPEG_DATA_WRITER_H_
#include
#include
#include
#include "guetzli/jpeg_data.h"
namespace guetzli {
// Function pointer type used to write len bytes into buf. Returns the
// number of bytes written or -1 on error.
typedef int (*JPEGOutputHook)(void* data, const uint8_t* buf, size_t len);
// Output callback function with associated data.
struct JPEGOutput {
JPEGOutput(JPEGOutputHook cb, void* data) : cb(cb), data(data) {}
bool Write(const uint8_t* buf, size_t len) const {
return (len == 0) || (cb(data, buf, len) == len);
}
private:
JPEGOutputHook cb;
void* data;
};
bool WriteJpeg(const JPEGData& jpg, bool strip_metadata, JPEGOutput out);
struct HuffmanCodeTable {
uint8_t depth[256];
int code[256];
};
void BuildSequentialHuffmanCodes(
const JPEGData& jpg, std::vector* dc_huffman_code_tables,
std::vector* ac_huffman_code_tables);
struct JpegHistogram {
static const int kSize = kJpegHuffmanAlphabetSize + 1;
JpegHistogram() { Clear(); }
void Clear() {
memset(counts, 0, sizeof(counts));
counts[kSize - 1] = 1;
}
void Add(int symbol) {
counts[symbol] += 2;
}
void Add(int symbol, int weight) {
counts[symbol] += 2 * weight;
}
void AddHistogram(const JpegHistogram& other) {
for (int i = 0; i + 1 < kSize; ++i) {
counts[i] += other.counts[i];
}
counts[kSize - 1] = 1;
}
int NumSymbols() const {
int n = 0;
for (int i = 0; i + 1 < kSize; ++i) {
n += (counts[i] > 0 ? 1 : 0);
}
return n;
}
uint32_t counts[kSize];
};
void BuildDCHistograms(const JPEGData& jpg, JpegHistogram* histo);
void BuildACHistograms(const JPEGData& jpg, JpegHistogram* histo);
size_t JpegHeaderSize(const JPEGData& jpg, bool strip_metadata);
size_t EstimateJpegDataSize(const int num_components,
const std::vector& histograms);
size_t HistogramEntropyCost(const JpegHistogram& histo,
const uint8_t depths[256]);
size_t HistogramHeaderCost(const JpegHistogram& histo);
void UpdateACHistogramForDCTBlock(const coeff_t* coeffs,
JpegHistogram* ac_histogram);
size_t ClusterHistograms(JpegHistogram* histo, size_t* num, int* histo_indexes,
uint8_t* depths);
} // namespace guetzli
#endif // GUETZLI_JPEG_DATA_WRITER_H_
================================================
FILE: guetzli/jpeg_error.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Definition of error codes for parsing jpeg files.
#ifndef GUETZLI_JPEG_ERROR_H_
#define GUETZLI_JPEG_ERROR_H_
namespace guetzli {
enum JPEGReadError {
JPEG_OK = 0,
JPEG_SOI_NOT_FOUND,
JPEG_SOF_NOT_FOUND,
JPEG_UNEXPECTED_EOF,
JPEG_MARKER_BYTE_NOT_FOUND,
JPEG_UNSUPPORTED_MARKER,
JPEG_WRONG_MARKER_SIZE,
JPEG_INVALID_PRECISION,
JPEG_INVALID_WIDTH,
JPEG_INVALID_HEIGHT,
JPEG_INVALID_NUMCOMP,
JPEG_INVALID_SAMP_FACTOR,
JPEG_INVALID_START_OF_SCAN,
JPEG_INVALID_END_OF_SCAN,
JPEG_INVALID_SCAN_BIT_POSITION,
JPEG_INVALID_COMPS_IN_SCAN,
JPEG_INVALID_HUFFMAN_INDEX,
JPEG_INVALID_QUANT_TBL_INDEX,
JPEG_INVALID_QUANT_VAL,
JPEG_INVALID_MARKER_LEN,
JPEG_INVALID_SAMPLING_FACTORS,
JPEG_INVALID_HUFFMAN_CODE,
JPEG_INVALID_SYMBOL,
JPEG_NON_REPRESENTABLE_DC_COEFF,
JPEG_NON_REPRESENTABLE_AC_COEFF,
JPEG_INVALID_SCAN,
JPEG_OVERLAPPING_SCANS,
JPEG_INVALID_SCAN_ORDER,
JPEG_EXTRA_ZERO_RUN,
JPEG_DUPLICATE_DRI,
JPEG_DUPLICATE_SOF,
JPEG_WRONG_RESTART_MARKER,
JPEG_DUPLICATE_COMPONENT_ID,
JPEG_COMPONENT_NOT_FOUND,
JPEG_HUFFMAN_TABLE_NOT_FOUND,
JPEG_HUFFMAN_TABLE_ERROR,
JPEG_QUANT_TABLE_NOT_FOUND,
JPEG_EMPTY_DHT,
JPEG_EMPTY_DQT,
JPEG_OUT_OF_BAND_COEFF,
JPEG_EOB_RUN_TOO_LONG,
JPEG_IMAGE_TOO_LARGE,
};
} // namespace guetzli
#endif // GUETZLI_JPEG_ERROR_H_
================================================
FILE: guetzli/jpeg_huffman_decode.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/jpeg_huffman_decode.h"
#include
#include
#include
#include
#include "guetzli/jpeg_data.h"
namespace guetzli {
// Returns the table width of the next 2nd level table, count is the histogram
// of bit lengths for the remaining symbols, len is the code length of the next
// processed symbol.
static inline int NextTableBitSize(const int* count, int len) {
int left = 1 << (len - kJpegHuffmanRootTableBits);
while (len < kJpegHuffmanMaxBitLength) {
left -= count[len];
if (left <= 0) break;
++len;
left <<= 1;
}
return len - kJpegHuffmanRootTableBits;
}
int BuildJpegHuffmanTable(const int* count_in, const int* symbols,
HuffmanTableEntry* lut) {
HuffmanTableEntry code; // current table entry
HuffmanTableEntry* table; // next available space in table
int len; // current code length
int idx; // symbol index
int key; // prefix code
int reps; // number of replicate key values in current table
int low; // low bits for current root entry
int table_bits; // key length of current table
int table_size; // size of current table
int total_size; // sum of root table size and 2nd level table sizes
// Make a local copy of the input bit length histogram.
int count[kJpegHuffmanMaxBitLength + 1] = { 0 };
int total_count = 0;
for (len = 1; len <= kJpegHuffmanMaxBitLength; ++len) {
count[len] = count_in[len];
total_count += count[len];
}
table = lut;
table_bits = kJpegHuffmanRootTableBits;
table_size = 1 << table_bits;
total_size = table_size;
// Special case code with only one value.
if (total_count == 1) {
code.bits = 0;
code.value = symbols[0];
for (key = 0; key < total_size; ++key) {
table[key] = code;
}
return total_size;
}
// Fill in root table.
key = 0;
idx = 0;
for (len = 1; len <= kJpegHuffmanRootTableBits; ++len) {
for (; count[len] > 0; --count[len]) {
code.bits = len;
code.value = symbols[idx++];
reps = 1 << (kJpegHuffmanRootTableBits - len);
while (reps--) {
table[key++] = code;
}
}
}
// Fill in 2nd level tables and add pointers to root table.
table += table_size;
table_size = 0;
low = 0;
for (len = kJpegHuffmanRootTableBits + 1;
len <= kJpegHuffmanMaxBitLength; ++len) {
for (; count[len] > 0; --count[len]) {
// Start a new sub-table if the previous one is full.
if (low >= table_size) {
table += table_size;
table_bits = NextTableBitSize(count, len);
table_size = 1 << table_bits;
total_size += table_size;
low = 0;
lut[key].bits = table_bits + kJpegHuffmanRootTableBits;
lut[key].value = (table - lut) - key;
++key;
}
code.bits = len - kJpegHuffmanRootTableBits;
code.value = symbols[idx++];
reps = 1 << (table_bits - code.bits);
while (reps--) {
table[low++] = code;
}
}
}
return total_size;
}
} // namespace guetzli
================================================
FILE: guetzli/jpeg_huffman_decode.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Utility function for building a Huffman lookup table for the jpeg decoder.
#ifndef GUETZLI_JPEG_HUFFMAN_DECODE_H_
#define GUETZLI_JPEG_HUFFMAN_DECODE_H_
#include
namespace guetzli {
static const int kJpegHuffmanRootTableBits = 8;
// Maximum huffman lookup table size.
// According to zlib/examples/enough.c, 758 entries are always enough for
// an alphabet of 257 symbols (256 + 1 special symbol for the all 1s code) and
// max bit length 16 if the root table has 8 bits.
static const int kJpegHuffmanLutSize = 758;
struct HuffmanTableEntry {
// Initialize the value to an invalid symbol so that we can recognize it
// when reading the bit stream using a Huffman code with space > 0.
HuffmanTableEntry() : bits(0), value(0xffff) {}
uint8_t bits; // number of bits used for this symbol
uint16_t value; // symbol value or table offset
};
// Builds jpeg-style Huffman lookup table from the given symbols.
// The symbols are in order of increasing bit lengths. The number of symbols
// with bit length n is given in counts[n] for each n >= 1.
// Returns the size of the lookup table.
int BuildJpegHuffmanTable(const int* counts, const int* symbols,
HuffmanTableEntry* lut);
} // namespace guetzli
#endif // GUETZLI_JPEG_HUFFMAN_DECODE_H_
================================================
FILE: guetzli/order.inc
================================================
// Automatically generated by guetzli/order:update_c_code
static const float csf[192] = {
0.0f,
1.71014f,
0.298711f,
0.233709f,
0.223126f,
0.207072f,
0.192775f,
0.161201f,
2.05807f,
0.222927f,
0.203406f,
0.188465f,
0.184668f,
0.169993f,
0.159142f,
0.130155f,
0.430518f,
0.204939f,
0.206655f,
0.192231f,
0.182941f,
0.169455f,
0.157599f,
0.127153f,
0.234757f,
0.191098f,
0.192698f,
0.17425f,
0.166503f,
0.142154f,
0.126182f,
0.104196f,
0.226117f,
0.185373f,
0.183825f,
0.166643f,
0.159414f,
0.12636f,
0.108696f,
0.0911974f,
0.207463f,
0.171517f,
0.170124f,
0.141582f,
0.126213f,
0.103627f,
0.0882436f,
0.0751848f,
0.196436f,
0.161947f,
0.159271f,
0.126938f,
0.109125f,
0.0878027f,
0.0749842f,
0.0633859f,
0.165232f,
0.132905f,
0.128679f,
0.105766f,
0.0906087f,
0.0751544f,
0.0641187f,
0.0529921f,
0.0f,
0.147235f,
0.11264f,
0.0757892f,
0.0493929f,
0.0280663f,
0.0075012f,
-0.000945567f,
0.149251f,
0.0964806f,
0.0786224f,
0.05206f,
0.0292758f,
0.00353094f,
-0.00277912f,
-0.00404481f,
0.115551f,
0.0793142f,
0.0623735f,
0.0405019f,
0.0152656f,
-0.00145742f,
-0.00370369f,
-0.00375106f,
0.0791547f,
0.0537506f,
0.0413634f,
0.0193486f,
0.000609066f,
-0.00510923f,
-0.0046452f,
-0.00385187f,
0.0544534f,
0.0334066f,
0.0153899f,
0.000539088f,
-0.00356085f,
-0.00535661f,
-0.00429145f,
-0.00343131f,
0.0356439f,
0.00865645f,
0.00165229f,
-0.00425931f,
-0.00507324f,
-0.00459083f,
-0.003703f,
-0.00310327f,
0.0121926f,
-0.0009259f,
-0.00330991f,
-0.00499378f,
-0.00437381f,
-0.00377427f,
-0.00311731f,
-0.00255125f,
-0.000320593f,
-0.00426043f,
-0.00416549f,
-0.00419364f,
-0.00365418f,
-0.00317499f,
-0.00255932f,
-0.00217917f,
0.0f,
0.143471f,
0.124336f,
0.0947465f,
0.0814066f,
0.0686776f,
0.0588122f,
0.0374415f,
0.146315f,
0.105334f,
0.0949415f,
0.0784241f,
0.0689064f,
0.0588304f,
0.0495961f,
0.0202342f,
0.123818f,
0.0952654f,
0.0860556f,
0.0724158f,
0.0628307f,
0.0529965f,
0.0353941f,
0.00815821f,
0.097054f,
0.080422f,
0.0731085f,
0.0636154f,
0.055606f,
0.0384127f,
0.0142879f,
0.00105195f,
0.0849312f,
0.071115f,
0.0631183f,
0.0552972f,
0.0369221f,
0.00798314f,
0.000716374f,
-0.00200948f,
0.0722298f,
0.0599559f,
0.054841f,
0.0387529f,
0.0107262f,
0.000355315f,
-0.00244803f,
-0.00335222f,
0.0635335f,
0.0514196f,
0.0406309f,
0.0125833f,
0.00151305f,
-0.00140269f,
-0.00362547f,
-0.00337649f,
0.0472024f,
0.0198725f,
0.0113437f,
0.00266305f,
-0.00137183f,
-0.00354158f,
-0.00341292f,
-0.00290074f
};
static const float bias[192] = {
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0f,
0.0
};
================================================
FILE: guetzli/output_image.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/output_image.h"
#include
#include
#include
#include
#include
#include
#include "guetzli/idct.h"
#include "guetzli/color_transform.h"
#include "guetzli/dct_double.h"
#include "guetzli/gamma_correct.h"
#include "guetzli/preprocess_downsample.h"
#include "guetzli/quantize.h"
namespace guetzli {
OutputImageComponent::OutputImageComponent(int w, int h)
: width_(w), height_(h) {
Reset(1, 1);
}
void OutputImageComponent::Reset(int factor_x, int factor_y) {
factor_x_ = factor_x;
factor_y_ = factor_y;
width_in_blocks_ = (width_ + 8 * factor_x_ - 1) / (8 * factor_x_);
height_in_blocks_ = (height_ + 8 * factor_y_ - 1) / (8 * factor_y_);
num_blocks_ = width_in_blocks_ * height_in_blocks_;
coeffs_ = std::vector(num_blocks_ * kDCTBlockSize);
pixels_ = std::vector(width_ * height_, 128 << 4);
for (int i = 0; i < kDCTBlockSize; ++i) quant_[i] = 1;
}
bool OutputImageComponent::IsAllZero() const {
int numcoeffs = num_blocks_ * kDCTBlockSize;
for (int i = 0; i < numcoeffs; ++i) {
if (coeffs_[i] != 0) return false;
}
return true;
}
void OutputImageComponent::GetCoeffBlock(int block_x, int block_y,
coeff_t block[kDCTBlockSize]) const {
assert(block_x < width_in_blocks_);
assert(block_y < height_in_blocks_);
int offset = (block_y * width_in_blocks_ + block_x) * kDCTBlockSize;
memcpy(block, &coeffs_[offset], kDCTBlockSize * sizeof(coeffs_[0]));
}
void OutputImageComponent::ToPixels(int xmin, int ymin, int xsize, int ysize,
uint8_t* out, int stride) const {
assert(xmin >= 0);
assert(ymin >= 0);
assert(xmin < width_);
assert(ymin < height_);
const int yend1 = ymin + ysize;
const int yend0 = std::min(yend1, height_);
int y = ymin;
for (; y < yend0; ++y) {
const int xend1 = xmin + xsize;
const int xend0 = std::min(xend1, width_);
int x = xmin;
int px = y * width_ + xmin;
for (; x < xend0; ++x, ++px, out += stride) {
*out = static_cast((pixels_[px] + 8 - (x & 1)) >> 4);
}
const int offset = -stride;
for (; x < xend1; ++x) {
*out = out[offset];
out += stride;
}
}
for (; y < yend1; ++y) {
const int offset = -stride * xsize;
for (int x = 0; x < xsize; ++x) {
*out = out[offset];
out += stride;
}
}
}
void OutputImageComponent::ToFloatPixels(float* out, int stride) const {
assert(factor_x_ == 1);
assert(factor_y_ == 1);
for (int block_y = 0; block_y < height_in_blocks_; ++block_y) {
for (int block_x = 0; block_x < width_in_blocks_; ++block_x) {
coeff_t block[kDCTBlockSize];
GetCoeffBlock(block_x, block_y, block);
double blockd[kDCTBlockSize];
for (int k = 0; k < kDCTBlockSize; ++k) {
blockd[k] = block[k];
}
ComputeBlockIDCTDouble(blockd);
for (int iy = 0; iy < 8; ++iy) {
for (int ix = 0; ix < 8; ++ix) {
int y = block_y * 8 + iy;
int x = block_x * 8 + ix;
if (y >= height_ || x >= width_) continue;
out[(y * width_ + x) * stride] = static_cast(blockd[8 * iy + ix] + 128.0);
}
}
}
}
}
void OutputImageComponent::SetCoeffBlock(int block_x, int block_y,
const coeff_t block[kDCTBlockSize]) {
assert(block_x < width_in_blocks_);
assert(block_y < height_in_blocks_);
int offset = (block_y * width_in_blocks_ + block_x) * kDCTBlockSize;
memcpy(&coeffs_[offset], block, kDCTBlockSize * sizeof(coeffs_[0]));
uint8_t idct[kDCTBlockSize];
ComputeBlockIDCT(&coeffs_[offset], idct);
UpdatePixelsForBlock(block_x, block_y, idct);
}
void OutputImageComponent::UpdatePixelsForBlock(
int block_x, int block_y, const uint8_t idct[kDCTBlockSize]) {
if (factor_x_ == 1 && factor_y_ == 1) {
for (int iy = 0; iy < 8; ++iy) {
for (int ix = 0; ix < 8; ++ix) {
int x = 8 * block_x + ix;
int y = 8 * block_y + iy;
if (x >= width_ || y >= height_) continue;
int p = y * width_ + x;
pixels_[p] = idct[8 * iy + ix] << 4;
}
}
} else if (factor_x_ == 2 && factor_y_ == 2) {
// Fill in the 10x10 pixel area in the subsampled image that will be the
// basis of the upsampling. This area is enough to hold the 3x3 kernel of
// the fancy upsampler around each pixel.
static const int kSubsampledEdgeSize = 10;
uint16_t subsampled[kSubsampledEdgeSize * kSubsampledEdgeSize];
for (int j = 0; j < kSubsampledEdgeSize; ++j) {
// The order we fill in the rows is:
// 8 rows intersecting the block, row below, row above
const int y0 = block_y * 16 + (j < 9 ? j * 2 : -2);
for (int i = 0; i < kSubsampledEdgeSize; ++i) {
// The order we fill in each row is:
// 8 pixels within the block, left edge, right edge
const int ix = ((j < 9 ? (j + 1) * kSubsampledEdgeSize : 0) +
(i < 9 ? i + 1 : 0));
const int x0 = block_x * 16 + (i < 9 ? i * 2 : -2);
if (x0 < 0) {
subsampled[ix] = subsampled[ix + 1];
} else if (y0 < 0) {
subsampled[ix] = subsampled[ix + kSubsampledEdgeSize];
} else if (x0 >= width_) {
subsampled[ix] = subsampled[ix - 1];
} else if (y0 >= height_) {
subsampled[ix] = subsampled[ix - kSubsampledEdgeSize];
} else if (i < 8 && j < 8) {
subsampled[ix] = idct[j * 8 + i] << 4;
} else {
// Reconstruct the subsampled pixels around the edge of the current
// block by computing the inverse of the fancy upsampler.
const int y1 = std::max(y0 - 1, 0);
const int x1 = std::max(x0 - 1, 0);
subsampled[ix] = (pixels_[y0 * width_ + x0] * 9 +
pixels_[y1 * width_ + x1] +
pixels_[y0 * width_ + x1] * -3 +
pixels_[y1 * width_ + x0] * -3) >> 2;
}
}
}
// Determine area to update.
int xmin = std::max(block_x * 16 - 1, 0);
int xmax = std::min(block_x * 16 + 16, width_ - 1);
int ymin = std::max(block_y * 16 - 1, 0);
int ymax = std::min(block_y * 16 + 16, height_ - 1);
// Apply the fancy upsampler on the subsampled block.
for (int y = ymin; y <= ymax; ++y) {
const int y0 = ((y & ~1) / 2 - block_y * 8 + 1) * kSubsampledEdgeSize;
const int dy = ((y & 1) * 2 - 1) * kSubsampledEdgeSize;
uint16_t* rowptr = &pixels_[y * width_];
for (int x = xmin; x <= xmax; ++x) {
const int x0 = (x & ~1) / 2 - block_x * 8 + 1;
const int dx = (x & 1) * 2 - 1;
const int ix = x0 + y0;
rowptr[x] = (subsampled[ix] * 9 + subsampled[ix + dy] * 3 +
subsampled[ix + dx] * 3 + subsampled[ix + dx + dy]) >> 4;
}
}
} else {
printf("Sampling ratio not supported: factor_x = %d factor_y = %d\n",
factor_x_, factor_y_);
exit(1);
}
}
void OutputImageComponent::CopyFromJpegComponent(const JPEGComponent& comp,
int factor_x, int factor_y,
const int* quant) {
Reset(factor_x, factor_y);
assert(width_in_blocks_ <= comp.width_in_blocks);
assert(height_in_blocks_ <= comp.height_in_blocks);
const size_t src_row_size = comp.width_in_blocks * kDCTBlockSize;
for (int block_y = 0; block_y < height_in_blocks_; ++block_y) {
const coeff_t* src_coeffs = &comp.coeffs[block_y * src_row_size];
for (int block_x = 0; block_x < width_in_blocks_; ++block_x) {
coeff_t block[kDCTBlockSize];
for (int i = 0; i < kDCTBlockSize; ++i) {
block[i] = src_coeffs[i] * quant[i];
}
SetCoeffBlock(block_x, block_y, block);
src_coeffs += kDCTBlockSize;
}
}
memcpy(quant_, quant, sizeof(quant_));
}
void OutputImageComponent::ApplyGlobalQuantization(const int q[kDCTBlockSize]) {
for (int block_y = 0; block_y < height_in_blocks_; ++block_y) {
for (int block_x = 0; block_x < width_in_blocks_; ++block_x) {
coeff_t block[kDCTBlockSize];
GetCoeffBlock(block_x, block_y, block);
if (QuantizeBlock(block, q)) {
SetCoeffBlock(block_x, block_y, block);
}
}
}
memcpy(quant_, q, sizeof(quant_));
}
OutputImage::OutputImage(int w, int h)
: width_(w),
height_(h),
components_(3, OutputImageComponent(w, h)) {}
void OutputImage::CopyFromJpegData(const JPEGData& jpg) {
for (size_t i = 0; i < jpg.components.size(); ++i) {
const JPEGComponent& comp = jpg.components[i];
assert(jpg.max_h_samp_factor % comp.h_samp_factor == 0);
assert(jpg.max_v_samp_factor % comp.v_samp_factor == 0);
int factor_x = jpg.max_h_samp_factor / comp.h_samp_factor;
int factor_y = jpg.max_v_samp_factor / comp.v_samp_factor;
assert(comp.quant_idx < jpg.quant.size());
components_[i].CopyFromJpegComponent(comp, factor_x, factor_y,
&jpg.quant[comp.quant_idx].values[0]);
}
}
namespace {
void SetDownsampledCoefficients(const std::vector& pixels,
int factor_x, int factor_y,
OutputImageComponent* comp) {
assert(pixels.size() == comp->width() * comp->height());
comp->Reset(factor_x, factor_y);
for (int block_y = 0; block_y < comp->height_in_blocks(); ++block_y) {
for (int block_x = 0; block_x < comp->width_in_blocks(); ++block_x) {
double blockd[kDCTBlockSize];
int x0 = 8 * block_x * factor_x;
int y0 = 8 * block_y * factor_y;
assert(x0 < comp->width());
assert(y0 < comp->height());
for (int iy = 0; iy < 8; ++iy) {
for (int ix = 0; ix < 8; ++ix) {
float avg = 0.0;
for (int j = 0; j < factor_y; ++j) {
for (int i = 0; i < factor_x; ++i) {
int x = std::min(x0 + ix * factor_x + i, comp->width() - 1);
int y = std::min(y0 + iy * factor_y + j, comp->height() - 1);
avg += pixels[y * comp->width() + x];
}
}
avg /= factor_x * factor_y;
blockd[iy * 8 + ix] = avg;
}
}
ComputeBlockDCTDouble(blockd);
blockd[0] -= 1024.0;
coeff_t block[kDCTBlockSize];
for (int k = 0; k < kDCTBlockSize; ++k) {
block[k] = static_cast(std::round(blockd[k]));
}
comp->SetCoeffBlock(block_x, block_y, block);
}
}
}
} // namespace
void OutputImage::Downsample(const DownsampleConfig& cfg) {
if (components_[1].IsAllZero() && components_[2].IsAllZero()) {
// If the image is already grayscale, nothing to do.
return;
}
if (cfg.use_silver_screen &&
cfg.u_factor_x == 2 && cfg.u_factor_y == 2 &&
cfg.v_factor_x == 2 && cfg.v_factor_y == 2) {
std::vector rgb = ToSRGB();
std::vector > yuv = RGBToYUV420(rgb, width_, height_);
SetDownsampledCoefficients(yuv[0], 1, 1, &components_[0]);
SetDownsampledCoefficients(yuv[1], 2, 2, &components_[1]);
SetDownsampledCoefficients(yuv[2], 2, 2, &components_[2]);
return;
}
// Get the floating-point precision YUV array represented by the set of
// DCT coefficients.
std::vector > yuv(3, std::vector(width_ * height_));
for (int c = 0; c < 3; ++c) {
components_[c].ToFloatPixels(&yuv[c][0], 1);
}
yuv = PreProcessChannel(width_, height_, 2, 1.3f, 0.5f,
cfg.u_sharpen, cfg.u_blur, yuv);
yuv = PreProcessChannel(width_, height_, 1, 1.3f, 0.5f,
cfg.v_sharpen, cfg.v_blur, yuv);
// Do the actual downsampling (averaging) and forward-DCT.
if (cfg.u_factor_x != 1 || cfg.u_factor_y != 1) {
SetDownsampledCoefficients(yuv[1], cfg.u_factor_x, cfg.u_factor_y,
&components_[1]);
}
if (cfg.v_factor_x != 1 || cfg.v_factor_y != 1) {
SetDownsampledCoefficients(yuv[2], cfg.v_factor_x, cfg.v_factor_y,
&components_[2]);
}
}
void OutputImage::ApplyGlobalQuantization(const int q[3][kDCTBlockSize]) {
for (int c = 0; c < 3; ++c) {
components_[c].ApplyGlobalQuantization(&q[c][0]);
}
}
void OutputImage::SaveToJpegData(JPEGData* jpg) const {
assert(components_[0].factor_x() == 1);
assert(components_[0].factor_y() == 1);
jpg->width = width_;
jpg->height = height_;
jpg->max_h_samp_factor = 1;
jpg->max_v_samp_factor = 1;
jpg->MCU_cols = components_[0].width_in_blocks();
jpg->MCU_rows = components_[0].height_in_blocks();
int ncomp = components_[1].IsAllZero() && components_[2].IsAllZero() ? 1 : 3;
for (int i = 1; i < ncomp; ++i) {
jpg->max_h_samp_factor = std::max(jpg->max_h_samp_factor,
components_[i].factor_x());
jpg->max_v_samp_factor = std::max(jpg->max_h_samp_factor,
components_[i].factor_y());
jpg->MCU_cols = std::min(jpg->MCU_cols, components_[i].width_in_blocks());
jpg->MCU_rows = std::min(jpg->MCU_rows, components_[i].height_in_blocks());
}
jpg->components.resize(ncomp);
int q[3][kDCTBlockSize];
for (int c = 0; c < 3; ++c) {
memcpy(&q[c][0], components_[c].quant(), kDCTBlockSize * sizeof(q[0][0]));
}
for (int c = 0; c < ncomp; ++c) {
JPEGComponent* comp = &jpg->components[c];
assert(jpg->max_h_samp_factor % components_[c].factor_x() == 0);
assert(jpg->max_v_samp_factor % components_[c].factor_y() == 0);
comp->id = c;
comp->h_samp_factor = jpg->max_h_samp_factor / components_[c].factor_x();
comp->v_samp_factor = jpg->max_v_samp_factor / components_[c].factor_y();
comp->width_in_blocks = jpg->MCU_cols * comp->h_samp_factor;
comp->height_in_blocks = jpg->MCU_rows * comp->v_samp_factor;
comp->num_blocks = comp->width_in_blocks * comp->height_in_blocks;
comp->coeffs.resize(kDCTBlockSize * comp->num_blocks);
int last_dc = 0;
const coeff_t* src_coeffs = components_[c].coeffs();
coeff_t* dest_coeffs = &comp->coeffs[0];
for (int block_y = 0; block_y < comp->height_in_blocks; ++block_y) {
for (int block_x = 0; block_x < comp->width_in_blocks; ++block_x) {
if (block_y >= components_[c].height_in_blocks() ||
block_x >= components_[c].width_in_blocks()) {
dest_coeffs[0] = last_dc;
for (int k = 1; k < kDCTBlockSize; ++k) {
dest_coeffs[k] = 0;
}
} else {
for (int k = 0; k < kDCTBlockSize; ++k) {
const int quant = q[c][k];
int coeff = src_coeffs[k];
assert(coeff % quant == 0);
dest_coeffs[k] = coeff / quant;
}
src_coeffs += kDCTBlockSize;
}
last_dc = dest_coeffs[0];
dest_coeffs += kDCTBlockSize;
}
}
}
SaveQuantTables(q, jpg);
}
std::vector OutputImage::ToSRGB(int xmin, int ymin,
int xsize, int ysize) const {
std::vector rgb(xsize * ysize * 3);
for (int c = 0; c < 3; ++c) {
components_[c].ToPixels(xmin, ymin, xsize, ysize, &rgb[c], 3);
}
for (size_t p = 0; p < rgb.size(); p += 3) {
ColorTransformYCbCrToRGB(&rgb[p]);
}
return rgb;
}
std::vector OutputImage::ToSRGB() const {
return ToSRGB(0, 0, width_, height_);
}
void OutputImage::ToLinearRGB(int xmin, int ymin, int xsize, int ysize,
std::vector >* rgb) const {
const double* lut = Srgb8ToLinearTable();
std::vector rgb_pixels = ToSRGB(xmin, ymin, xsize, ysize);
for (int p = 0; p < xsize * ysize; ++p) {
for (int i = 0; i < 3; ++i) {
(*rgb)[i][p] = static_cast(lut[rgb_pixels[3 * p + i]]);
}
}
}
void OutputImage::ToLinearRGB(std::vector >* rgb) const {
ToLinearRGB(0, 0, width_, height_, rgb);
}
std::string OutputImage::FrameTypeStr() const {
char buf[128];
int len = snprintf(buf, sizeof(buf), "f%d%d%d%d%d%d",
component(0).factor_x(), component(0).factor_y(),
component(1).factor_x(), component(1).factor_y(),
component(2).factor_x(), component(2).factor_y());
return std::string(buf, len);
}
} // namespace guetzli
================================================
FILE: guetzli/output_image.h
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef GUETZLI_OUTPUT_IMAGE_H_
#define GUETZLI_OUTPUT_IMAGE_H_
#include
#include
#include "guetzli/jpeg_data.h"
namespace guetzli {
class OutputImageComponent {
public:
OutputImageComponent(int w, int h);
void Reset(int factor_x, int factor_y);
int width() const { return width_; }
int height() const { return height_; }
int factor_x() const { return factor_x_; }
int factor_y() const { return factor_y_; }
int width_in_blocks() const { return width_in_blocks_; }
int height_in_blocks() const { return height_in_blocks_; }
const coeff_t* coeffs() const { return &coeffs_[0]; }
const int* quant() const { return &quant_[0]; }
bool IsAllZero() const;
// Fills in block[] with the 8x8 coefficient block with block coordinates
// (block_x, block_y).
// NOTE: If the component is 2x2 subsampled, this corresponds to the 16x16
// pixel area with upper-left corner (16 * block_x, 16 * block_y).
void GetCoeffBlock(int block_x, int block_y,
coeff_t block[kDCTBlockSize]) const;
// Fills in out[] array with the 8-bit pixel view of this component cropped
// to the specified window. The window's upper-left corner, (xmin, ymin) must
// be within the image, but the window may extend past the image. In that
// case the edge pixels are duplicated.
void ToPixels(int xmin, int ymin, int xsize, int ysize,
uint8_t* out, int stride) const;
// Fills in out[] array with the floating-point precision pixel view of the
// component.
// REQUIRES: factor_x() == 1 and factor_y() == 1.
void ToFloatPixels(float* out, int stride) const;
// Sets the 8x8 coefficient block with block coordinates (block_x, block_y)
// to block[].
// NOTE: If the component is 2x2 subsampled, this corresponds to the 16x16
// pixel area with upper-left corner (16 * block_x, 16 * block_y).
// REQUIRES: block[k] % quant()[k] == 0 for each coefficient index k.
void SetCoeffBlock(int block_x, int block_y,
const coeff_t block[kDCTBlockSize]);
// Requires that comp is not downsampled.
void CopyFromJpegComponent(const JPEGComponent& comp,
int factor_x, int factor_y,
const int* quant);
void ApplyGlobalQuantization(const int q[kDCTBlockSize]);
private:
void UpdatePixelsForBlock(int block_x, int block_y,
const uint8_t idct[kDCTBlockSize]);
const int width_;
const int height_;
int factor_x_;
int factor_y_;
int width_in_blocks_;
int height_in_blocks_;
int num_blocks_;
std::vector coeffs_;
std::vector pixels_;
// Same as last argument of ApplyGlobalQuantization() (default is all 1s).
int quant_[kDCTBlockSize];
};
class OutputImage {
public:
OutputImage(int w, int h);
int width() const { return width_; }
int height() const { return height_; }
OutputImageComponent& component(int c) { return components_[c]; }
const OutputImageComponent& component(int c) const { return components_[c]; }
// Requires that jpg is in YUV444 format.
void CopyFromJpegData(const JPEGData& jpg);
void ApplyGlobalQuantization(const int q[3][kDCTBlockSize]);
// If sharpen or blur are enabled, preprocesses image before downsampling U or
// V to improve butteraugli score and/or reduce file size.
// u_sharpen: sharpen the u channel in red areas to improve score (not as
// effective as v_sharpen, blue is not so important)
// u_blur: blur the u channel in some areas to reduce file size
// v_sharpen: sharpen the v channel in red areas to improve score
// v_blur: blur the v channel in some areas to reduce file size
struct DownsampleConfig {
// Default is YUV420.
DownsampleConfig() : u_factor_x(2), u_factor_y(2),
v_factor_x(2), v_factor_y(2),
u_sharpen(true), u_blur(true),
v_sharpen(true), v_blur(true),
use_silver_screen(false) {}
int u_factor_x;
int u_factor_y;
int v_factor_x;
int v_factor_y;
bool u_sharpen;
bool u_blur;
bool v_sharpen;
bool v_blur;
bool use_silver_screen;
};
void Downsample(const DownsampleConfig& cfg);
void SaveToJpegData(JPEGData* jpg) const;
std::vector ToSRGB() const;
std::vector ToSRGB(int xmin, int ymin, int xsize, int ysize) const;
void ToLinearRGB(std::vector >* rgb) const;
void ToLinearRGB(int xmin, int ymin, int xsize, int ysize,
std::vector >* rgb) const;
std::string FrameTypeStr() const;
private:
const int width_;
const int height_;
std::vector components_;
};
} // namespace guetzli
#endif // GUETZLI_OUTPUT_IMAGE_H_
================================================
FILE: guetzli/preprocess_downsample.cc
================================================
/*
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "guetzli/preprocess_downsample.h"
#include
#include
#include
#include
using std::size_t;
namespace {
// convolve with size*size kernel
std::vector Convolve2D(const std::vector& image, int w, int h,
const double* kernel, int size) {
auto result = image;
int size2 = size / 2;
for (size_t i = 0; i < image.size(); i++) {
int x = i % w;
int y = i / w;
// Avoid non-normalized results at boundary by skipping edges.
if (x < size2 || x + size - size2 - 1 >= w
|| y < size2 || y + size - size2 - 1 >= h) {
continue;
}
float v = 0;
for (int j = 0; j < size * size; j++) {
int x2 = x + j % size - size2;
int y2 = y + j / size - size2;
v += static_cast(kernel[j]) * image[y2 * w + x2];
}
result[i] = v;
}
return result;
}
// convolve horizontally and vertically with 1D kernel
std::vector Convolve2X(const std::vector& image, int w, int h,
const double* kernel, int size, double mul) {
auto temp = image;
int size2 = size / 2;
for (size_t i = 0; i < image.size(); i++) {
int x = i % w;
int y = i / w;
// Avoid non-normalized results at boundary by skipping edges.
if (x < size2 || x + size - size2 - 1 >= w) continue;
float v = 0;
for (int j = 0; j < size; j++) {
int x2 = x + j - size2;
v += static_cast(kernel[j]) * image[y * w + x2];
}
temp[i] = v * static_cast(mul);
}
auto result = temp;
for (size_t i = 0; i < temp.size(); i++) {
int x = i % w;
int y = i / w;
// Avoid non-normalized results at boundary by skipping edges.
if (y < size2 || y + size - size2 - 1 >= h) continue;
float v = 0;
for (int j = 0; j < size; j++) {
int y2 = y + j - size2;
v += static_cast(kernel[j]) * temp[y2 * w + x];
}
result[i] = v * static_cast(mul);
}
return result;
}
double Normal(double x, double sigma) {
static const double kInvSqrt2Pi = 0.3989422804014327;
return std::exp(-x * x / (2 * sigma * sigma)) * kInvSqrt2Pi / sigma;
}
std::vector Sharpen(const std::vector& image, int w, int h,
float sigma, float amount) {
// This is only made for small sigma, e.g. 1.3.
std::vector kernel(5);
for (size_t i = 0; i < kernel.size(); i++) {
kernel[i] = Normal(1.0 * i - kernel.size() / 2, sigma);
}
double sum = 0;
for (size_t i = 0; i < kernel.size(); i++) sum += kernel[i];
const double mul = 1.0 / sum;
std::vector result =
Convolve2X(image, w, h, kernel.data(), kernel.size(), mul);
for (size_t i = 0; i < image.size(); i++) {
result[i] = image[i] + (image[i] - result[i]) * amount;
}
return result;
}
void Erode(int w, int h, std::vector* image) {
std::vector temp = *image;
for (int y = 1; y + 1 < h; y++) {
for (int x = 1; x + 1 < w; x++) {
size_t index = y * w + x;
if (!(temp[index] && temp[index - 1] && temp[index + 1]
&& temp[index - w] && temp[index + w])) {
(*image)[index] = 0;
}
}
}
}
void Dilate(int w, int h, std::vector* image) {
std::vector temp = *image;
for (int y = 1; y + 1 < h; y++) {
for (int x = 1; x + 1 < w; x++) {
size_t index = y * w + x;
if (temp[index] || temp[index - 1] || temp[index + 1]
|| temp[index - w] || temp[index + w]) {
(*image)[index] = 1;
}
}
}
}
std::vector Blur(const std::vector& image, int w, int h) {
// This is only made for small sigma, e.g. 1.3.
static const double kSigma = 1.3;
std::vector kernel(5);
for (size_t i = 0; i < kernel.size(); i++) {
kernel[i] = Normal(1.0 * i - kernel.size() / 2, kSigma);
}
double sum = 0;
for (size_t i = 0; i < kernel.size(); i++) sum += kernel[i];
const double mul = 1.0 / sum;
return Convolve2X(image, w, h, kernel.data(), kernel.size(), mul);
}
} // namespace
namespace guetzli {
// Do the sharpening to the v channel, but only in areas where it will help
// channel should be 2 for v sharpening, or 1 for less effective u sharpening
std::vector> PreProcessChannel(
int w, int h, int channel, float sigma, float amount, bool blur,
bool sharpen, const std::vector>& image) {
if (!blur && !sharpen) return image;
// Bring in range 0.0-1.0 for Y, -0.5 - 0.5 for U and V
auto yuv = image;
for (size_t i = 0; i < yuv[0].size(); i++) {
yuv[0][i] /= 255.0;
yuv[1][i] = yuv[1][i] / 255.0f - 0.5f;
yuv[2][i] = yuv[2][i] / 255.0f - 0.5f;
}
// Map of areas where the image is not too bright to apply the effect.
std::vector darkmap(image[0].size(), false);
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
size_t index = y * w + x;
float y = yuv[0][index];
float u = yuv[1][index];
float v = yuv[2][index];
float r = y + 1.402f * v;
float g = y - 0.34414f * u - 0.71414f * v;
float b = y + 1.772f * u;
// Parameters tuned to avoid sharpening in too bright areas, where the
// effect makes it worse instead of better.
if (channel == 2 && g < 0.85 && b < 0.85 && r < 0.9) {
darkmap[index] = true;
}
if (channel == 1 && r < 0.85 && g < 0.85 && b < 0.9) {
darkmap[index] = true;
}
}
}
Erode(w, h, &darkmap);
Erode(w, h, &darkmap);
Erode(w, h, &darkmap);
// Map of areas where the image is red enough (blue in case of u channel).
std::vector redmap(image[0].size(), false);
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
size_t index = y * w + x;
float u = yuv[1][index];
float v = yuv[2][index];
// Parameters tuned to allow only colors on which sharpening is useful.
if (channel == 2 && 2.116 * v > -0.34414 * u + 0.2
&& 1.402 * v > 1.772 * u + 0.2) {
redmap[index] = true;
}
if (channel == 1 && v < 1.263 * u - 0.1 && u > -0.33741 * v) {
redmap[index] = true;
}
}
}
Dilate(w, h, &redmap);
Dilate(w, h, &redmap);
Dilate(w, h, &redmap);
// Map of areas where to allow sharpening by combining red and dark areas
std::vector sharpenmap(image[0].size(), 0);
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
size_t index = y * w + x;
sharpenmap[index] = redmap[index] && darkmap[index];
}
}
// Threshold for where considered an edge.
const double threshold = (channel == 2 ? 0.02 : 1.0) * 127.5;
static const double kEdgeMatrix[9] = {
0, -1, 0,
-1, 4, -1,
0, -1, 0
};
// Map of areas where to allow blurring, only where it is not too sharp
std::vector blurmap(image[0].size(), false);
std::vector edge = Convolve2D(yuv[channel], w, h, kEdgeMatrix, 3);
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
size_t index = y * w + x;
float u = yuv[1][index];
float v = yuv[2][index];
if (sharpenmap[index]) continue;
if (!darkmap[index]) continue;
if (fabs(edge[index]) < threshold && v < -0.162 * u) {
blurmap[index] = true;
}
}
}
Erode(w, h, &blurmap);
Erode(w, h, &blurmap);
// Choose sharpened, blurred or original per pixel
std::vector sharpened = Sharpen(yuv[channel], w, h, sigma, amount);
std::vector blurred = Blur(yuv[channel], w, h);
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
size_t index = y * w + x;
if (sharpenmap[index]) {
if (sharpen) yuv[channel][index] = sharpened[index];
} else if (blurmap[index]) {
if (blur) yuv[channel][index] = blurred[index];
}
}
}
// Bring back to range 0-255
for (size_t i = 0; i < yuv[0].size(); i++) {
yuv[0][i] *= 255.0;
yuv[1][i] = (yuv[1][i] + 0.5f) * 255.0f;
yuv[2][i] = (yuv[2][i] + 0.5f) * 255.0f;
}
return yuv;
}
namespace {
inline float Clip(float val) {
return std::max(0.0f, std::min(255.0f, val));
}
inline float RGBToY(float r, float g, float b) {
return 0.299f * r + 0.587f * g + 0.114f * b;
}
inline float RGBToU(float r, float g, float b) {
return -0.16874f * r - 0.33126f * g + 0.5f * b + 128.0f;
}
inline float RGBToV(float r, float g, float b) {
return 0.5f * r - 0.41869f * g - 0.08131f * b + 128.0f;
}
inline float YUVToR(float y, float u, float v) {
return y + 1.402f * (v - 128.0f);
}
inline float YUVToG(float y, float u, float v) {
return y - 0.344136f * (u - 128.0f) - 0.714136f * (v - 128.0f);
}
inline float YUVToB(float y, float u, float v) {
return y + 1.772f * (u - 128.0f);
}
// TODO(user) Use SRGB->linear conversion and a lookup-table.
inline float GammaToLinear(float x) {
return static_cast(std::pow(x / 255.0f, 2.2));
}
// TODO(user) Use linear->SRGB conversion and a lookup-table.
inline float LinearToGamma(float x) {
return 255.0 * std::pow(x, 1.0 / 2.2);
}
std::vector LinearlyAveragedLuma(const std::vector