User "Hashar" posted a comment on MediaWiki.r87099. Full URL: https://secure.wikimedia.org/wikipedia/mediawiki/wiki/Special:Code/MediaWiki/87099#c17865 Commit summary:
Provisional fix for Bug #28631 to remove artifacts from GIF. This seems better in my (very) limited testing than leaving it in, but I'd like to get more tests. Comment: Just for the context, this only apply when matching the three conditions: - image/gif - animated imagemagick >= 6.3.5 The options which were passed to ImageMagick were: - fuzz 5% - layers optimizeTransparency - +map +map is supposed to look at the color map and generate the minimum map needed to represent the image. I do not think this parameter is the root cause although removing it might fix the issue as a side effect. I believe the root cause is the 'fuzz 5%' associated to the optimize transparency switch. >From the documentation at >http://www.imagemagick.org/script/command-line-options.php : '''optimize-transparency''' : Given a GIF animation, replace any pixel in the sub-frame overlay images with transparency, if it does not change the resulting animation by more than the current -fuzz factor. : This should allow a existing frame optimized GIF animation to compress into a smaller file size due to larger areas of one (transparent) color rather than a pattern of multiple colors repeating the current disposed image of the last frame. I am wondering if removing the fuzz option will be enough. Might be worth checking a newer imagemagick version and/or open an upstream bug. _______________________________________________ MediaWiki-CodeReview mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/mediawiki-codereview
