User blog comment:Defchris/Why are so many lossy-lossless anime pics here?/@comment-1940096-20111115001309/@comment-1636-20111115024809

The anime images come from a lossy source - mpeg2 nor h264 artifacts don't go away by using png instead of jpegs. Furthermore all given compression artifacts from the lossy codecs reduce the compression efficiency of png.

Well compressed jpegs don't lose that much quality that the 10x size of pngs are justified. The linked jpeg image is compressed with 1:1:1 chroma settings and with 90% image quality - and in your png there are way more compression artifacts...

It is different with monochrome images though - pngs get as small as jpegs.