first cs depend case: brighness,contrast

[Casper Boemann]

I've investigated changing brightness a bit.

photoshop and a page on the internet both add a constant to each of the 
channels. This is what krita did too.

In the hsb colorselector of photoshop (havn't tested any other) changing 
(B)rightness scales rgb channels by a factor instead.

I'm a bit confused as to what to do.

CIE defines lightness L* which is what people mean when they say brightness.
This L* is part of CIELAB

So currently I intend to convert to CIELAB, change the lightness, and convert 
back.

I think this is the _right_ thing to do.

-- 
best regards / venlig hilsen
Casper Boemann