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Mail Archives: djgpp/2000/12/14/21:11:52

From: Tom St Denis <stdenis AT compmore DOT net>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Loading multiple bitmaps in allegro?
Date: Fri, 15 Dec 2000 01:29:10 GMT
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References: <3a39477a DOT 22177941 AT news DOT virgin DOT net> <91brpk$qh2$1 AT nnrp1 DOT deja DOT com>
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In article <91brpk$qh2$1 AT nnrp1 DOT deja DOT com>,
  Tom St Denis <stdenis AT compmore DOT net> wrote:
> In article <3a39477a DOT 22177941 AT news DOT virgin DOT net>,
>   jamesb_420 AT hotmail DOT com (JB) wrote:
> > I am trying to load multiple bitmaps using allegro, but i can't get
> > them all to load in the correct color because the pallete is only
set
> > for one.
> > What can i do?
>
> Turn your desk 90 degrees?
>
> Honestly just create a "total color usage" (i.e a 64x64x64 array of
> longs) and select the 256 most used colors.  Then dither your images
> (i.e closest mean deviation for the RGB triplets) to fit the same pal.
>
> If you're smart in the future you would use the same palette :-)

To clarify I meant do something like

long col[64][64][64];

... step through pixels
++col[pal[pixel[x]].r][pal[pixel[x].g][pal[pixel[x].b]];

Where pixel[x] is a 8-bit pixel value (addressed by x) and pal[] is
your array

struct pal {
   unsigned char r,g,b };

of palette values.  The table would take about a MB of memory... not
too much as long as you can free it up...

Then you sort the table looking for the 256 highest values.  Then you
step through your bitmaps again and replace the color with one from
your new palette that has the smallest mean deviation.

Tom


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