(I don't know what's the best place to drop such stuff so I dropped it here also)
1. Compresses better with 8bpp than 4bpp - seen some time ago, can't find it anymore :-(
2. Compresses poorly (brewn by me) :
http://freefile.kristopherw.us/uploads/temp/pngspeci.zip (1'295 Byte's)
GAMMA669.PNG 669 | 450 x 450 , 10 colours | PNGoutWIN :-(
BMP : 102'718
LibPNG (NCONVERT) : 915
PNGOUT : 844 (799 with DeflOPT)
OptiPNG : 694 (N/A for DeflOPT)
PNGoutWIN : 669 ### WINNER ###
ZIP (only data) : 302 !!! 2.21 !!!
Source (use32) : 195
INT1587.PNG 1'901 | 680 x 520 , 1'574 colours | OptiPNG
BMP : 1'060'854
LibPNG (NCONVERT) : 2'329
PNGOUT : 1'946 (1'943 with DeflOPT)
OptiPNG : 1'901 (N/A for DeflOPT) ### WINNER ###
PNGoutWIN : no test
ZIP (only data) : 370 !!! 5.14 !!!
Source (use16) : 87
As we can see, PNGOUT is (exceptionally) inferior to OPTIPNG, but the BIG ECLAT is
that the "most optimized" PNG's can be ZIP'ped by factor 2.21 or 5.14 !!!
Also, both PNGOUT and OPTIPNG are inferior to PNGoutWIN :-(
At least, my source code size is impossible to beat :-)
3. PNG inferior to GIF ???
6 screenshots (3 small and 3 big) and I'm unable to convert them into
PNG without loss or bloat increase ... WtF ????