GNOME Bugzilla – Bug 165023
non-grey transparency indicator
Last modified: 2008-01-15 12:46:08 UTC
This is referring to the checkerboard pattern that acts as the ultimate background in transparent and smei-transparent regions of an image. Normally, light and dark grey are used. I find green (#00ff00) and magenta (#ff00ff) to be better. Please add this to the choices. Also, this would make a nice default. Try it; you'll like it.
It would be rather difficult to implement this. For efficiency, the display is scaled and composited on the checkerboard pattern in one go. This code uses a LUT that relies on the grayscale property of the background. Of course this could be changed, but it would be a lot of work and it would certainly slow things down. Unless a reasonable use case is added here, this request should be closed WONTFIX.
Created attachment 36456 [details] reasonable use case The fireman is uneven grey. His background is too. The grey checkerboard pattern is very poor for working with him. Bright green works pretty well, as does magenta.
You can't just use 3 LUTs? Anyway, I attached a reasonable use case image for you. The grey checkerboard pattern is useless for editing the alpha channel. Look at the folds of silvery cloth along the fireman's legs. The original background consisted of grey rocks. Carving the fireman out of his background was hopeless with the grey checkerboard pattern.
Created attachment 36461 [details] reasonable use case, original JPEG This is the original fireman image. It's a public domain photo from the US Air Force.
I agree that the default gray pattern is not optimal for working with images that contain a lot of gray. I usually solve that problem by creating a new background layer behind the one that I am editing and I fill that layer with bright red or green. It would be nice to have a way to customize the colors of the checkerboard pattern, but I am not sure that it is worth the effort, considering that some workarounds are available.
I of course used the work-around suggested in comment #5. This eats lots of memory. This could perhaps be solved via some sort of pattern-fill layer. I found my system swapping like mad when I added green and magenta layers. There's also the problem of file saving. You have to get rid of the layers when you wish to save. All in all, the work-around is painful. It's just that, a work-around.
I should add that I now use green (and often magenta too) for all images that I work with. The bright colors are simply better, even with images that aren't mostly grey. So this isn't just some obscure case for pictures like the fireman image. I've used the green+magenta layers for trees, a football, a soccerball, a fire, and so on. The only recent image that I used the grey checkerboard for was a candle, and that's only because setting up the green+magenta was too much work for a quick job.
Albert, we know that you are a weird guy. You are still just one out of many GIMP users and definitely one of the most annoying ones.
Closing as WONTFIX based on comments and the existence of a workaround. If anybody has a patch to contribute that accomplishes what is requested here, feel free to reopen.
The comments regarding efficiency appear to be incorrect. If they were correct, then compositing extra layers would be a problem --> better get rid of the layers feature???
You seem to know the code well enough to provide a patch then? :)