GNOME Bugzilla – Bug 796276
Drawable filter preview on layer masks doesn't look like final result on 8-bit images
Last modified: 2018-05-24 20:11:16 UTC
Created attachment 372244 [details] xcf for bug reproduction I am using GIMP to create a transparent background for a product shot (8-bit image). To do this I am trying to apply a Gradient in "Multiply" mode to a layer mask I created of my image. "preview_gradient.png" shows a smooth gradient between black and to the layer mask color. But when I press Enter, I get different results (seen in "applied_gradient.png"). The result look much more jaggy than the preview, which I did not expect. I am using GIMP 2.10.0 in flatpak. To workaround this, I tried changing blend color space, dithering/adaptive supersampling/legacy-mode/other "darken" blend modes too but without much luck (they all yield different results but none of the results looks as good as the preview, they all suffer from the same "look").
Created attachment 372245 [details] gradient as it looks when previewed
Created attachment 372246 [details] gradient as it looks when applied
This is just how the layer mask *looks* when viewed. Layer masks are now always encoded as linear data, but they have exactly the same effect on the layer as in GIMP 2.8. The data in the mask is the same as before, it simply looks different. This is only a problem with 8-bit images, and there is not really a way to fix it. In 16 and 32 bit images, the effect is not noticeable because we have enough values.
I apologize, but I'm not sure I understood your comment. I was trying to describe that my preview looks different from what I ended up getting. From a usability point of view, this was unexpected.
(In other words, if the result is supposed to look like that, I would assume that the preview should look like that too.)
Oh right, that's true. We just fixed that for filters on indexed images, we can use the same mechanism here.
-- GitLab Migration Automatic Message -- This bug has been migrated to GNOME's GitLab instance and has been closed from further activity. You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.gnome.org/GNOME/gimp/issues/1482.