On 10/04/2010 04:17 AM, David Gowers (kampu) wrote:

> Try making a flat region of color #2a7e23, selecting Pencil tool,
> choosing Color mode and a large brush, and painting #11e500 repeatedly
> over the same area.
> [...]
> In general, you can manifest this bug by picking a dark color,
> making a region of it, and painting over with a HSV value-increased
> version of same color.
> Ideally, this would possibly change Hue or Chromaticity, but shouldn't
> change Lightness significantly. Looking at the LCH color selector, L
> rises ~2 points for each paint application in my example.

Unfortunately, that's not fixable but a result of the too small gamut of 
the sRGB working space.
Combining the lightness of #2a7e23 with hue/saturation of #11e500 
results in (linear) sRGB values which are negative for red and blue. 
Clipping those to 0-255 yields the result you observed (the color 
becomes lighter than it should be).

Whenever you observe this misbehavior, at least one of the resulting RGB 
components should be at 0 or 255 -- otherwise it really would be a bug.

The only fix is to use a larger working space, like scRGB.


Gimp-developer mailing list

Reply via email to