Skip to content

Aggressive zopfli optimizations, reduces PNG sizes by 35%

Anthony Ryan requested to merge anthonyryan1/adwaita-icon-theme:master into master
  • Try all zopflipng filter modes on each image
  • Discard 16bit color information (not currently used as far as I can see)
  • Modify transparent pixel data to optimize compression

I experimented with a few different options and found this was the sweet spot between size reduction and CPU time when rendering new images.

Adding additional zopfli iterations or using both OptiPNG and ZopfliPNG could yield up to 1% in additional savings but was too far into diminishing returns territory, since it made the compression take 5-10x longer than this for such negligible improvements.

Merge request reports