Originally Posted by Honf
Setting the color pallet to 16 make the images look very bad (they open just fine in windows image viewer). Seems like the Kindle has a slight problem with its png decompresser.
Yeah, if you simply used
pngcrush -plte_len 16 ...
it could generate an invalid PNG. That dangerous option is only for truncating a palette with unused entries at the top. To actually quantize your image down to 16 colors with pngcrush you also need to set the bit-depth to 4, i.e.,
pngcrush -bit_depth 4 -plte_len 16 ..
which simply drops the low 4 bits of each color sample, or you could use another application like ImageMagick or pngquant to get a better-looking quantization. I'll look into making pngcrush give a better error return if valid palette entries are being truncated with the -plte_len option. ../glennrp