GNOME Bugzilla – Bug 767745
Weird gradient map behaviour in grayscale mode
Last modified: 2016-06-17 13:01:13 UTC
What was done:
1. Create a new image.
2. Change mode to grayscale.
3. Select a black and white linear gradient.
4. Cover the canvas with that gradient.
(See 'before_gradient_map.png' to see my canvas at this stage.)
5. Apply gradient map.
(See 'after_gradient_map.png' to see my canvas at this stage.)
What was observed:
The gradient is split. Rather than a gradient from black to white, the canvas shows a gradient from 50% gray to white, then black to 50% gray.
What was expected:
Mapping a black and white linear gradient to a black and white linear gradient shouldn't change anything. The behaviour appears to be correct in RGB mode.
Created attachment 329910 [details]
image before applying gradient map
Created attachment 329911 [details]
image after applying gradient map
I can confirm this happens in 2.8, but is gone in GIMP HEAD - there gradient map behaves as expected on grayscale images.
Closing as fixed.
Suggested workaround for people using 2.8 is to convert the image temporarily to RGB mode before applying a Gradient Map.