commit | 41b8cdab7815c79a060938bfe0c24337e2eb9e54 | [log] [tgz] |
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author | Moritz Firsching <firsching@google.com> | Wed Feb 07 08:33:15 2024 |
committer | Moritz Firsching <firsching@google.com> | Wed Feb 07 09:27:11 2024 |
tree | 2a5ea9f48e72ffaa7d237abcc4a8932e83fd05f3 | |
parent | 9df48f11143d0b2dd8fb3fb35a287abd41e3c728 [diff] |
add v0.9.2 to changelog
This repository contains a reference implementation of JPEG XL (encoder and decoder), called libjxl
. This software library is used by many applications that support JPEG XL.
JPEG XL was standardized in 2022 as ISO/IEC 18181. The core codestream is specified in 18181-1, the file format in 18181-2. Decoder conformance is defined in 18181-3, and 18181-4 is the reference software.
The library API, command line options, and tools in this repository are subject to change, however files encoded with cjxl
conform to the JPEG XL specification and can be decoded with current and future djxl
decoders or the libjxl
decoding library.
In most Linux distributions, installing libjxl
is just a matter of using the package management system. For example in Debian-based distributions: apt install libjxl-tools
will install cjxl
and djxl
and other tools like benchmark_xl
are available in the package libjxl-devtools
. On MacOS, you can use Homebrew: brew install jpeg-xl
.
From the releases page the following can be downloaded:
Of course you can also build libjxl from sources.
To encode a source image to JPEG XL with default settings:
cjxl input.png output.jxl
The desired visual fidelity can be selected using the --distance
parameter (in units of just-noticeable difference, where 0 is lossless and the most useful lossy range is 0.5 .. 3.0), or using --quality
(on a scale from 0 to 100, roughly matching libjpeg). The encode effort can be selected using the --effort
parameter.
For more settings run cjxl --help
or for a full list of options run cjxl -v -v --help
.
To decode a JPEG XL file run:
djxl input.jxl output.png
When possible cjxl
/djxl
are able to read/write the following image formats: .exr, .gif, .jpeg/.jpg, .pfm, .pgm/.ppm, .pgx, .png. Specifically for JPEG files, the default cjxl
behavior is to apply lossless recompression and the default djxl
behavior is to reconstruct the original JPEG file (when the extension of the output file is .jpg).
For speed benchmarks on single images in single or multi-threaded decoding djxl
can print decoding speed information. See djxl --help
for details on the decoding options and note that the output image is optional for benchmarking purposes.
For more comprehensive benchmarking options, see the benchmarking guide.
Besides the libjxl
library API documentation, there are example applications and plugins that can be used as a reference or starting point for developers who wish to integrate libjxl
in their project.
This software is available under a 3-clause BSD license which can be found in the LICENSE file, with an “Additional IP Rights Grant” as outlined in the PATENTS file.
Please note that the PATENTS file only mentions Google since Google is the legal entity receiving the Contributor License Agreements (CLA) from all contributors to the JPEG XL Project, including the initial main contributors to the JPEG XL format: Cloudinary and Google.
If you encounter a bug or other issue with the software, please open an Issue here.
There is a subreddit about JPEG XL, and informal chatting with developers and early adopters of libjxl
can be done on the JPEG XL Discord server.