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Changing transparency to imitate grays

Oct 24, 2013, 23:09
Post: #1
Changing transparency to imitate grays
Hi folks, I have a Grayscale image where pixels are either white, transparent, or nearly white. My issue is, I need to convert this image such that:

1. All colors are converted to solid white with with an alpha channel (##FFFFFF)
2. The image looks unchanged

For example I want to convert a pixel that is FCFCFC to FFFFFF, but change the alpha channel so that they look the same. I'm assuming a black background.

Is there an easy way of doing this? Sorry if I'm not being clear... I'm fairly new with the Gimp and imaging in general.[/align]

Thanks!
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Oct 25, 2013, 07:43 (This post was last modified: Oct 25, 2013 07:44 by iForStyle007.)
Post: #2
RE: Changing transparency to imitate grays
mrpete, could you also maybe link to an example of a similar effect/image that you saw that did this?

Or is it for printing/image fixing purposes?

Won't the picture be blank if you convert all the pixel colors to solid white? Sorry if I don't fully understand the request.
Color 2 alpha from my field tests have taken out the color you click, making that picked color transparent.
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Oct 26, 2013, 11:40
Post: #3
RE: Changing transparency to imitate grays
(Oct 25, 2013 11:00)ofnuts Wrote:  
(Oct 25, 2013 10:59)ofnuts Wrote:  
(Oct 25, 2013 07:43)iForStyle007 Wrote:  Color 2 alpha from my field tests have taken out the color you click, making that picked color transparent.

This is exactly what is needed. The "contract" of C2A is that if you use C2A to remove some color form a layer, then superposing the resulting layer over a layer filled with the removed color will reproduce exactly the original image. In the case required by the OP, the fully white pixels will remain white, but the gray pixels will become pure white, made partially transparent so that the partially transparent pure white, when put over black, recreates the original gray.

Hmmm, That clears up the jist of it, after re-reading OP's post, I think I understand better now
Quote: Won't the picture be blank if you convert all the pixel colors to solid white? Sorry if I don't fully understand the request.

mrpete did say he had some transparent pixels & a black background, so maybe after the color2aplha it would just show the transparent pixels? It would be nice to have a visual sample from him though of possible(a before & after would be bonus.)

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