Adept - the adaptive JPG Compressor
- Please install a MSS saliency algorithm binary, ImageMagick, MozJPEG and JPEGrescan
- Make MozJPEG available as "mozjpeg" in your $PATH, e.g. via symlink
- Fetch a copy of adept and place it somewhere you deem a good place for 3rd party shellscripts, e.g. "/usr/local/bin". Make sure the location is in the $PATH of the user(s) who will run adept and ensure that the script is executable (chmod -x).
- Symlink it as "adept" for your own convenience
- Now you can run "adept /path/to/image.jpg" to compress JPEGs far more effectively!
When compressing JPEG images, the same compression level is used on the entire image. However, most JPEG images contain homogeneous and heterogeneous areas, which are varyingly well-suited for compression. Compressing heterogeneous areas in JPEGs to reduce filesize causes compression artefacts due to the lossy nature of JPEG compression.
This script adaptively alters the compression level for areas within JPEGs (per-block) to achieve optimized file size while maintaining a decent visual quality. This script achieves a significantly reduced file size compared to standard tools such as cjpeg while maintaining good visual quality, as can be measured via SSIM. This is good news for the Web Performance and thus Web Developer community to achieve a great user experience on websites.
In alphabetical order:
- Andy Davies
- Gregor Fabritius
- Neil Jedrzejewski
- Alessandro Lenzen
- Claus Meteling
- André Roaldseth
- Christian Schäfer
- Yoav Weiss
This software is published under the BSD licence 3.0
Copyright (c) 2015, Tobias Baldauf All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
- Neither the name of the author nor the names of contributors may be used to endorse or promote products derived from this software without specific prior written permission.
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