PNG automatic image compression

automatic, image, compression, png

« lossless » on HC RGBA

pingo's fast transformation heuristic (lossless)
original pingo -auto
157.00 KB 21.71 KB — 0.17s

« lossless » on LC RGBA

pingo's fast transformation heuristic (lossy)
original pingo -auto
339.41 KB 26.14 KB — 0.12s

« lossy » on HC RGBA

pingo's fast transformation heuristic (lossy)
original pingo -auto
567.48 KB 122.75 KB — 0.31s
butteraugli 3.4608132839 — 3-norm: 1.040871
ssimulacra 0.01204299

« lossy » on LC RGBA

pingo's fast transformation heuristic (lossy)
original pingo -auto
494.19 KB 27.68 KB — 0.16s
butteraugli 5.9512929916 — 3-norm: 1.684199
ssimulacra 0.00775929

« lossy » on LC RGB

pingo's fast transformation heuristic (lossy)
original pingo -auto
5.60 KB 4.13 KB — 0.12s
butteraugli 0.6234656572 — 3-norm: 0.136168
ssimulacra 0.00040054

« conversion » on HC RGB

automatic conversion from PNG to JPG if applicable
original pingo -auto
369.00 KB 54.60 KB — 0.10s (JPG)
butteraugli 2.9461371899 — 3-norm: 1.135771
ssimulacra 0.02684828

notes

pingo rc3 (10) 
pingo -auto target

note that this function could be work in progress and would not always perform as well as demonstrate on any samples. the lossless compression level over this transformation can be increased to get smaller filesize by using -sN:

N: from 0 to 9 — 0: fast and good compression — 9: slow, but better compression 
pingo flags -sN target

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