first cs depend case: brighness,contrast

[Grzegorz Borowiak]

On Mon, 6 Jun 2005, Casper Boemann wrote:

> I have indentified that the brightness contrast filter assumes rgb (or at
> least liniar tristimulas values).

Here is an advantage of YUV :)

In YUV, brightness/contrast applies to luma channel only, leaving both
chromas unchanged.

For saturation, you change chromas independently, and hue manipulation is
also simple - 2x2 matrix/vector multiplication of chromas (rotation
around luma axis).

-- 
Grzes