Re: [Gimp-developer] something wrong with healing brush

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/06/2017 02:26 AM, Alexander Rabtchevich wrote:
> Hello
>
> It seems healing brush is broken. It produces artifacts and the result 
> is not as before. I guess it happened when color transform code was 
> involved, but that's only a supposition.
See this bug report: https://bugzilla.gnome.org/show_bug.cgi?id=783755

The healing tool uses Subtract to calculate color differences, which 
only produces expected results when using RGB encoded more or less 
perceptually. But using Subtract on perceptually uniform RGB does 
produce obvious gamma artifacts in extreme cases that maybe would never 
come up in normal editing.

Regardless of the extreme cases, if Subtract is used to calculate color 
differences, the healing tool should use perceptually uniform RGB. But 
instead of using Subtract, it might be better to use LAB to calculate 
color differences.

Best,
Elle