Re: [darktable-dev] HSL and RGB scene-referred space

2020-04-16 Thread Aurélien Pierre
Hello, 1. you go from RGB to XYZ using the ICC profile of the RGB space you are using, which gives you the coeffs of the 3×3 matrix RGB -> XYZ. Call that matrix M. Do a matrix dot product [XYZ] = [M] * [RGB] 2. you go from XYZ to Yxy using x = X / (X + Y + Z) and y = Y / (X + Y + Z) 3.

Re: [darktable-dev] HSL and RGB scene-referred space

2020-04-11 Thread Harold le Clément
Hello, Thanks a lot for the feedback. Agree, the problem would be only when trying to use the saturation for parametric masking (as the color picker HSL mode is only used for that). Perhaps a cylindrical HSY could be used, but it depends how the saturation is computed (most of the information I

Re: [darktable-dev] HSL and RGB scene-referred space

2020-04-10 Thread Moritz Moeller
On 10.4.20 11:27, Harold le Clément wrote: - Is this a real issue or is this a bad usage of darktable? I.e. shall we never have RGB values higher that 1.0 in the pipe? As a user I would expect to keep the dynamic range throughout the pipe for as long as possible. If a module clips it would