nanogui: Pallete and bitmap problem
Subject:
Re: [nanogui] Pallete and bitmap problem
From:
"Greg Haerr" ####@####.####
Date:
16 Apr 2008 16:10:56 -0000
Message-Id: <2cb901c89fdc$63843790$0300a8c0@RDP>
: Then when I convert the image into smaller 8 bit pallete file (see
http://www.pavelpaces.net/mwin/Bkg.bmp
: ).
: Then I get result depicted in the
http://www.pavelpaces.net/mwin/BkgBad.bmp,
: where colors are somehow disturbed.
When you use an 8bpp bitmap, the colors are converted to a maximum
of 256 different colors, and they are put into a palette that is
carried with the .bmp file. Depending on your display bpp, which
you didn't specify, these may be re-converted to another palette
or to your screen bpp. Thus, there may be considerable degradation.
Some of these conversions have been disabled/enabled for various
reasons. The code that handles this is in engine/devdraw.c, I think
DrawImage, or something like that. The image decoder is in
engine/image_bmp.c.
Regards,
Greg
