Freedom251 › Image Compression Software
ACACIA
What ACACIA is
ACACIA is free, open-source software for compressing JPEG and WebP images on Linux and Windows. You can set a target image quality or file size, and its machine-learning method predicts how each image will compress before adjusting compression strength. A graphical interface is available, while command-line mode supports batch processing. The README lists version 0.17 and describes the project as a demonstration of research techniques rather than production software. ACACIA is intended for previously uncompressed images; previously compressed files may produce less accurate results. Images with alpha channels and images containing high-contrast vector graphics are unsupported. The program requires a processor with AVX and AVX2 instructions. Building requires Qt, libjpeg or libjpeg-turbo, and libwebp. It is licensed under GPL-3.0. On Windows, the graphical interface does not currently scale properly on 4K screens.
Who it suits
ACACIA suits users who want a free compression tool for JPEG or WebP files and can work within its image and hardware requirements. It is also aimed at people interested in research-oriented software rather than production software.
What it does well
- Targets image quality or file size
- Machine learning adjusts compression per image
- Graphical and command-line interfaces
- Batch processing supported
- Free and GPL-3.0 licensed
What to know first
- Not intended as production software
- Alpha-channel images are unsupported
- Requires AVX and AVX2 CPU support
- Windows interface scales poorly on 4K screens
Verdict
ACACIA offers targeted JPEG and WebP compression with both graphical and batch command-line workflows. Its research status, input restrictions, processor requirement, and Windows 4K scaling issue should be considered before adoption.
Facts from ACACIA's own pages
- API access
- No · github.com, 24 Sept 2026
- Batch processing
- Yes · github.com, 24 Sept 2026
- Build requirements
- Building requires Qt, libjpeg and libwebp, and the program requires a CPU with AVX and AVX2 support. · github.com, 11 Oct 2026
- Compression method
- It uses machine learning to predict how an individual image will compress and adjusts compression aggressiveness accordingly. · github.com, 11 Oct 2026
- Compression modes
- lossy · github.com, 24 Sept 2026
- Contact
- The README lists John Thomson and Oleksandr Murashko as contacts at the University of St Andrews. · github.com, 11 Oct 2026
- Dependencies
- Building it requires Qt, libjpeg or libjpeg-turbo, and libwebp. · github.com, 11 Oct 2026
- Free plan
- Yes · github.com, 24 Sept 2026
- Image compatibility
- The software is designed for previously uncompressed images; previously compressed images may produce less accurate results. · github.com, 11 Oct 2026
- Input suitability
- It is designed for previously uncompressed images; previously compressed images may produce less accurate results. · github.com, 11 Oct 2026
- Integration licensing
- The README says users interested in integrating ACACIA under a different license can contact the maintainers to discuss it. · github.com, 11 Oct 2026
- Interfaces
- It provides a graphical interface and a command line mode for batch processing. · github.com, 11 Oct 2026
- License
- ACACIA is free, open source software licensed under GPL-3.0. · github.com, 11 Oct 2026
- Method
- It uses machine learning to predict how an image will compress and adjusts compression strength for each image. · github.com, 11 Oct 2026
- Performance requirement
- The program uses AVX and AVX2 vector instructions, so it requires a CPU that supports them. · github.com, 11 Oct 2026
- Purpose
- ACACIA is an image compression tool that targets specified image quality or file size when compressing JPEG or WebP images. · github.com, 11 Oct 2026
- Research citation
- The README asks research users to cite the paper “Predicting and Optimizing Image Compression,” published in the Proceedings of the 2016 ACM Conference on Multimedia. · github.com, 11 Oct 2026
- Research status
- The README says ACACIA is not production software and is primarily intended to demonstrate research techniques. · github.com, 11 Oct 2026
- Support contact
- The README invites users to contact John Thomson at [email protected] with feedback or interest. · github.com, 11 Oct 2026
- Supported formats
- JPEG,WebP · github.com, 24 Sept 2026
- Unsupported images
- Alpha channel images and images with high-contrast vector graphics are not supported. · github.com, 11 Oct 2026
- Version
- The README lists the current version as 0.17. · github.com, 11 Oct 2026
- Windows limitation
- The README notes that the Windows graphical interface does not currently scale properly on 4K screens. · github.com, 11 Oct 2026
Where ACACIA stands on Freedom251
- Image Compression Software#79 of 85