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  1. #1
    will code HTML for food Michel V's Avatar
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    I was just playing around with the Gimp, made a colorful image into black&white mode, undoed, then desaturated the colors.
    Although they were both black&white, the results were different !

    Why is it so ? Any specialist to enlighten me ?
    [blogger: zengun] [blogware contributor: wordpress]

  2. #2
    Don't get too close, I bite! Nicky's Avatar
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    Have a look at this website which has a lot of useful info about color!

  3. #3
    Bored One boredboi's Avatar
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    This is just what i think... i'm only guessing...

    When you Black&White an image, it checks each pixel's brightness, and if its above 50% it becomes white, if below 50% it becomes black.

    However when you desaturate an image, you're only making it closer to grey, so if you desaturate it 100%, the brighter hues (red, yellow, green) would become white, and the other hues (cyan, blue, purple) would become black?

  4. #4
    SitePoint Enthusiast spleenboy's Avatar
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    Although I've never touched a Gimp, here's my guess:

    Changing to black and white converts the color information into black/white information. A black/white image contains only two colors in its palatte: black 'n' white.

    Desaturate removes the color information without changing it, leaving only the brightness information. A desaturated image should contain 256 shades of gray.
    s-p-l-e-e-n-d-i-f-e-r-o-u-s

  5. #5
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    boredboi This is just what i think... i'm only guessing...

    When you Black&White an image, it checks each pixel's brightness, and if its above 50% it becomes white, if below 50% it becomes black.

    However when you desaturate an image, you're only making it closer to grey, so if you desaturate it 100%, the brighter hues (red, yellow, green) would become white, and the other hues (cyan, blue, purple) would become black?
    you're thinking of line art where you only have black or white values as opposed to a greyscale where you have a full range of b&w values.

    converting to b&w replaces the color values into greyscale values while desaturating removes the color values, which might looks the same on screen, but if it's going to press the ink densities will be completely different resulting in a bad looking printed image.
    <Edited by atomicmunky on 12-26-2000 at 07:08 PM>
    . . . chris


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