Colors: White if background is DARK and BLACK when is LIGHT

Question

I draw some text in a custom Label.

User can modify the label background, but the control shoud accomodate the text visibility in dependence of the specified background.

So, when the background is DARK I want to draw white foreground text, when its LIGHT I want BLACK foreground.

How to "understand" if the color is LIGHT or DARK?

http://stackoverflow.com/questions/97646/how-do-i-determine-darker-or-lighter-color-variant-of-a-given-color/97697#97697 — KMån, Jun 21 '11 at 10:50
@KMån: I don't need a darker or lighter variant of a color. I need to detect if a given color is light or dark by itself. — serhio, Jul 06 '11 at 08:01
You might want to accept your own answer. Using a predefined function is clearly better than re-inventing the wheel. — CodesInChaos, Jul 06 '11 at 19:14

score 3 · Accepted Answer · answered Jun 21 '11 at 10:43

3

A simple solution is to add the color componets of the background color and compare them to a threshold.

You might want to give blue a lower weight. 0.3*R+0.6*G+0.1*B is a common choice.

answered Jun 21 '11 at 10:43

CodesInChaos

score 2 · Answer 2 · answered Jul 06 '11 at 09:40

2

answered Jul 06 '11 at 09:40

serhio

2 Answers2