OpenEuphoria

RE: color difference equations

• Posted by Tone Škoda <tskoda at email.si> Sep 30, 2004
• 486 views

mic _ wrote:
> 
> Where did you get that code from? It looks very similar to something I wrote 
> a long time ago, but I can't remember for what program.

Yes, I think it's your code because I already once asked this question on this
mailing list.
BTW it works exactly the same as function found on
http://www.compuphase.com/cmetric.htm

> Anyway, you could view the two colors as 3D vectors and calculate the 
> difference in length of the vectors, the angle between the vectors or some 
> other measure.  Or you could calculate the luma of each color and take the 
> difference between those (where luma = 0.299*R + 0.587*G + 0.114*B). I bet 
> there are lots of other formulaes.

The problem is that this color difference needs to be very accurate, equal to
the way humans see it.
I either need to get a copy of some working accurate color difference formula
(which I can't find on the net) or I need to spend a lot of time to write my own.
For grayscale I have some idea, but for colors it will be more difficult.

These greyscale colors need to have these color differences:
{{8,8,8},{28,28,28}},    -- smallest color difference
{{33,33,33},{43,43,43}}, -- bigger color difference
{{33,33,33},{53,53,53}}  -- biggest color difference