[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [pygame] Re: Pygame 1.7.1 for Python 2.5 and BMP
> Sorry :(
> I've attached a BMP in this message, I don't know what is a RLE-compressed
> BMP? And Why does this is working with the python 2.4 version ?
RLE is common for image file formats that were designed for low
bit-depths. BMP files may or may not be run-length encoded (check the
program that saves out the file to see if it has settings for this).
GIF, at least in its GIF89a incarnation, doesn't use RLE, but instead
Lempel-Ziv-Welch (LZW) compression. As an aside: Unisys held a patent on
LZW compression up to 2003 in the US and 2004 in several other countries.
During the period where Unisys was defending their patent, many people
moved to using PNG instead, and some people used libraries which output
legal GIF files, but without compression. (Look for "libungif".)
Looking at your attached BMP, I would have expected to see non-zero values
in locations 0x1e-0x21 if it was run-length encoded, so I suspect the
actual cause for the problem is somewhere else.
Sorry that won't solve your problems, but perhaps it will guide someone
else to the solution.