1 reply to this topic

[PkK]

png2cv 0.13 has been released today and can be downloaded from
http://colecovision....nt/png2cv.shtml

Compared to the previous release this version produces outpout more
suitable for compression.

Example:
The representation of characters in the ColecoVision has some
redundancy, e.g. swapping the two colors in a line and inverting the
pattern will not change how a line looks on screen. Thus, by swapping
colors the pattern can be inverted and the other way 'round. This can be
used to create longer sequences of identical bytes in the pattern and
color tables, which can be compressed better.

Philipp

[newcoleco]

PkK, on Sun Oct 18, 2009 7:11 AM, said:

Example:
The representation of characters in the ColecoVision has some
redundancy, e.g. swapping the two colors in a line and inverting the
pattern will not change how a line looks on screen. Thus, by swapping
colors the pattern can be inverted and the other way 'round. This can be
used to create longer sequences of identical bytes in the pattern and
color tables, which can be compressed better.

It's always a good thing to optimize the output. This problem did haunted me during the first years, when I was dealing with BMP2PP and wondering why by default the empty spaces have a green color, so my first tools did decode the picture and try to optimize for compression, like your example suggest. So, I did implement optimization in my own bitmap tools, but I've reccently find out that if there is no real graphic to deal with, my algorithm just crash by looping forever. So, in my more reccent tools, I didn't apply the optimization until I fix the bug.