ECT 0.9.5

Release 0.9.5 includes several bug fixes.
Notably, a rare infinite loop during deflate-based compression was fixed that could occur when compressing data with long runs of repeated bytes. Users are strongly encouraged to upgrade.

Bugs fixed
#119
#126
#133
#125

Full Changelog: v0.9.4...v0.9.5

Note that the Windows and x86-64 macOS binaries below are cross-compiled and have not been tested – YMMV.

ECT 0.9.4

This release focuses on bug fixes as well as improving PNG color reductions. There are also some more match search performance improvements, which should improve PNG performance across the board.

Changes

• Update to latest lodepng, including slight performance improvements, bug fixes and refactoring contributions by @woot000
• Further performance improvements for match search and zlib longest_match()
• Updated zlib, mozjpeg and libpng
• Compression improvements based on better dirty alpha cleaning for palette images and color reductions to 'key'-based transparency (inspired by @NeRdTheNed's input)
• Refactor optipng code and improve file access pattern

Bugs fixed

#61
#104
#108
#110
#114

Full Changes

v0.9.3...v0.9.4

ECT 0.9.3

This is primarily a bug fix release.

• Resolve issues #64 and #74

• Fix regression in Windows compression ratio, primarily in mode 1

• Fixes for std::filesystem folder support on windows

• Fix rare longest_match() crash

• Fix MSVC compilation (#100)

• Fix compiler and static analyzer warnings, undefined behavior

• Additional slight speedup for PNG/Gzip mode 1 on high-redundancy files building on the last release

Note: Binaries updated to fix an issue where ECT would crash when optimizing gzip files with a missing FNAME field. This bug was introduced in version 0.9.2 when the gzip support was overhauled.

ECT 0.9.2

• A wide range of performance improvements. In particular, the zlib fork was overhauled, resulting in a much faster mode 1 for PNG files. This revamped mode 1 is now also available on GZIP/ZIP files, where it will produce results comparable to gzip -9 with better performance. Modes 2 and above will now be faster, especially for files with high redundancy due to a number of improvements to match finding and parsing. Text will only be slightly faster while PNG files should see larger improvements.
• Switch from boost::filesystem to std::filesystem to support processing directories. When using a modern compiler supporting std::filesystem, directory processing will be enabled without requiring external dependencies. The Windows binary now includes directory support.
• When creating or optimizing gzip files, ECT now maintains the file name.

Note that the initial Windows binary had issues with JPEG compression. This issue was entirely with the binary due to issues when switching from the regular compile to cross-compiling, not with the code itself. An updated binary where the problem is resolved has been added below.

ECT 0.9.1

Changes: (v0.9...v0.9.1)

• various build fixes
• The previous release included changes within mozjpeg that changed the DC scan optimization mode. This improved compression on some files but worsened it on others. This version uses mode 2 instead, which usually results in better compression. While some files will compress better with mode 0 as used in version 0.9 and modes 1 and 2 can affect the display during progressive image decoding, this should be the most sensible option for ECT and generally provide better compression.

ECT 0.9

Changes: (v0.8.3...v0.9)

• add support for bin output path by @CT1994 (#87)
• change mozjpeg build system and update to libjpeg-turbo 2.1.3. This includes some minor compression improvements.
• Changes to jpeg huffman code generation: Speed improvements, in particular for small files; insignificant compression improvements inspired by approach taken in libjpeg 9d

ECT 0.8.3

Bug fixes, build improvements and various functional improvements

ECT 0.8.2

Added allfilters-cheap
JPEG optimizations
Bug fixes
Memory leaks fixed
Improved deflate performance on x64-windows

ECT 0.8.1

Bug & compilation fixes

ECT 0.8

Changelog:
Keep file modification date in zipped files
Bug fixes
Faster JPEG compression
More PNG compression through smarter filtering
Updated mozjpeg
Make it possible to keep modification time
Allow recompression of zip files with different extension
Compress zip within zip
Note: Building now requires recursive cloning