[Newbies] Coloring images with transparant parts

[Matthias Korn]

Hi Bert,

I have quite a hard time understanding how to use color maps. And I
really did not find any helpful documentation on them for Squeak.

One example I found in the image is in BitBlt class>>exampleColorMap.
But I don't know how to use it with a Form/BitBlt, well, and what the
heck they are actually doing there...
In most occasions they used the Bitmap class instead of ColorMap and I
couldn't find anything to convert.

Could you provide a simple code example on how to modify the color
map of a Form? Or any other pointers....

Thanks a lot,
Matthias


Am Sat, 22 Nov 2008 01:58:33 +0100
schrieb Bert Freudenberg <bert at freudenbergs.de>:

> On 22.11.2008, at 01:15, Matthias Korn wrote:
> 
> > Hi,
> >
> > thanks for your hints. I also found ColorForm>>replaceColor:with:  
> > which
> > does what you describe. But it is unfortunately not what I was
> > looking for. I wasn't very clear in my original post:
> >
> > I (now) have a gray-scale image which I want to colorize, that is I
> > want to change the hue of the image and not just replace a color
> > with another (or floodfill for that matter).
> >
> > Hope you guys have some ideas. I tried searching with the Method  
> > Finder,
> > but my poor english didn't take me very far.
> 
> 
> Use a color map. Your grayscale image could be 8 bits, so with a 256  
> entries palette you can map that to any color(s) you want. Color
> maps are used in ColorForm, or directly with BitBlt.
> 
> - Bert -
> 
> 
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-- 
Matthias Korn
Institut für Wirtschaftsinformatik
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Universität Siegen
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