PNG optimizer (web lossless)

PNG, lossless, compression, image

« web lossless » on HC RGBA

pingo's fast heuristic for near-optimal filtering
original OptiPNG -o7 PNGOUT
147.62 KB no savings — 6.910s no savings — 1.790s
TruePNG -o4 oxipng -o 6 -a -Z ZopfliPNG 1
54.14 KB — 6.874s 51.98 KB — 35.081s 52.21 KB — 520.11s
ECT 2 pingo -s9
50.70 KB — 353.49s 50.69 KB — 0.62s

« web lossless » on LC RGBA to paletted

pingo's fast heuristic for near-optimal palette sorting
original OptiPNG -o7 PNGOUT
330.26 KB no savings — 28.016s no savings — 11.761s
TruePNG -o4 oxipng -o 6 -a -Z ZopfliPNG 1
57.30 KB — 6.874s 88.36 KB — 218.521s 63.49 KB — 438.141s
ECT 2 pingo -s9
63.24 KB — 1107.602s 55.37 KB — 0.57s

notes

1 ZopfliPNG 7113f4e
zopflipng --iterations=500 --filters=01234mepb --lossy_transparent target
2 ECT 0.8.3
ect -9 --mt-deflate --allfilters-b --pal_sort=120 target
OptiPNG 0.7.7
optipng -o7 target
Oxipng 6d2756d
oxipng -o 6 -a -Z target
PNGOUT 02/13/2015
pngout target
TruePNG 0.6.2.5
truepng -o4 target
pingo rc3 (02)
pingo -s9 target

note that this function could not always perform as well as demonstrate — it could offer worse results according to the sample

machine test: CPU G1820 2.7Ghz — 1.88GB RAM — Windows 7, 32-bit