[cairo] [PATCH] Add support for RGBA128F and RGB96F formats.

Maarten Lankhorst maarten.lankhorst at linux.intel.com
Wed Jun 27 12:27:44 UTC 2018

Op 12-06-18 om 22:00 schreef Bill Spitzak:
> If the values are 0-1 then one bit of exponent is not used, and also the sign bit it not used. So you could claim there are two wasted bits.
> However in all practical cases floating point is a better representation of image brightness than any integer representation of a linear or gamma corrected value as long as you have 16 or more bits per channel. Hardware support and standardization is a big win.
> And going outside the 0-1 range is very useful. >1 is necessary to represent HDR, and negative numbers allow infinite color spaces. It is true that some compositing operators designed for sRGB don't deal with this well, but I think the solution is to just not use them if you have such data.
I think sticking to the 0-1 range is good, HDR support would still be possible but I don't think cairo has support for it currently. :)
Nothing about the format would prevent it though.

Any consensus on 3 floats for RGB or 4 floats with the 4th set to 1.0?


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