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rgb values change randomly?! TImage?! TBitmap?!

Posted on 2001-06-25
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Last Modified: 2010-04-06
hi,

i'm making a simple colouring program. the program uses a colorbar i made myself. the colorbar consists of 39 rgb colors.

i've filled a simple black & white picture with some colors (using floodfill). now comes the trickiest part..
i've loaded the original black and white picture in a TImage(image1). and i've loaded the painted picture in another TImage(image2). Now, when i try to color the original picture, my program checks if the color i'm using is the same as the color i used before (and that is now on image2).

i'm using canvas.pixels[x,y] to determine to color of the pixel at [x,y] on image2 and i compare it with the current brush color i'm about to use.

in some cases the colors match and that's, cuz that's what i want. but in a lot of cases the colors differ a little. e.g. color about to be used on image1 = rgb(130,189,140) while the original color(image2) = rgb(130,187,139). this doesnt match, thus is wrong.

the essence of the program is, that a color can only be used when it matches. remember i'm only using the 39 colors.

it's very frustating...

thanks in advance
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Question by:brutebass
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TheNeil earned 300 total points
ID: 6224246
What pixel format are you using? Try setting the pixel format for your two images to be 24 bit:

Image1.Picture.Bitmap.PixelFormat := pf24Bit;

If you're using a 256 colour bitmap or your screen depth isn'y 24 bit then WIndows will either dither the colour (not likely) or go for a close approximation, and it's this that's causing your colour values to differ slightly

The Neil =:)
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Author Comment

by:brutebass
ID: 6224280
both images are already 24bit images. and the timage controls are already set to pf24bit. didnt fix my problem...
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Author Comment

by:brutebass
ID: 6224313
it did fix my problem..hehe ... forgot one thing to test...
thanks man!
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Expert Comment

by:TheNeil
ID: 6224546
Anytime

The Neil =:)
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