Implement --lossy LZW compression #72
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--lossy option that allows inexact match against LZW dictionary, which improves compression ratio. Lossy matching does a bit of 1-dimensional dithering. This is a very basic implementation that does recursive search of dictionary nodes. write_compressed_data contains some duplicated code, because the lossy search function needs to use less optimized code (ignores imageline), although this probably could be refactored a bit. The results are pretty good: — Original: 3.3MB — Lossy: 1.25MB Based on gifsicle which implements lossy LZW compression. It can reduce animgif file sizes by 30%—50% at a cost of some dithering/noise. — https://pornel.net/lossygif — https://github.com/pornel/giflossy Closed: kohler#16
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Based on gifsicle which implements lossy LZW compression.
It can reduce animgif file sizes by 30%—50% at a cost of some dithering/noise.
--lossyoption that allows inexact match against LZW dictionary, which improves compression ratio.Lossy matching does a bit of 1-dimensional dithering.
This is a very basic implementation that does recursive search of dictionary nodes.
write_compressed_datacontains some duplicated code, because the lossy search function needs to use less optimized code (ignoresimageline), although this probably could be refactored a bit.The results are pretty good:
Original: 3.3MB
Lossy: 1.25MB
Closed: #16