Hi everyone, when working with color profiles, the main historic issue was the non-linearity of the sensors/films. Now, it is rather that the color profile is performed on a chart having 6-7 EV of dynamic range while modern cameras have 12-15 EV. Simple gamma corrections (invented for CRT screens) don't work anymore, and video editors have invented a new standard able to remap the dynamic range and to fix the mid-tones at once : https://www.youtube.com/watch?v=kVKnhJN-BrQ&index=7&list=PLa1F2ddGya_9XER0wnFS6Mgnp3T-hgSZO
I have embedded the formula used in Blender (https://en.wikipedia.org/wiki/ASC_CDL) into the profile correction module of dt (using the same parameters for each RGB channel). The result looks more natural than the current version, without gamut or saturation issues in the highlights. It also speeds-up the worflow, since all is needed is this module to adjust the dynamic range, then a tone curve in auto RGB mode shaped as a stiff S to bring back the contrast. The result is much better than with the tonemapping modules, with less color fixes. I'm a newbie at C and it's the first time I achieve something inside dt, so I could use some reviews on my code and also some help on the OpenCL part (the kernel does not load, I don't know why) : https://github.com/aurelienpierre/darktable/tree/color-grading Thanks a lot ! Aurélien. ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
