Hi Linus,
On Fri, 27 Sep 2019 at 13:37, Linus Walleij linus.walleij@linaro.org wrote:
Also the ILI9322 can actually set up gamma correction which is very nice for professional applications. I haven't seen any way for DRM to do gamma correction properly or any framework for it to adjust and propagate gamma to/from userspace (seems like another enormous task), but I am pretty sure it will be there one of these days so I put in some comments and placeholders.
Gamma correction has been supported since approximately the dawn of time with a 3x8-bit LUT.
Obviously more modern hardware has far more complex colour management. This is also supported, and is approximately described here: https://dri.freedesktop.org/docs/drm/gpu/drm-kms.html#color-management-prope...
Both planes and CRTCs can have a LUT -> matrix transform -> LUT pipeline. There are also additional properties for fixed transforms, e.g. limited 16-235 <-> full 0-255 range translation.
Cheers, Daniel