Posted by julian_m on 07/04/06 09:22

Do anyone know an algorithm which retieves a grey value given certain
rgb value?

I'm needing this kind of function:

$grey = RGBtoGrey('#ffffff');

where $grey (function's return value) should be a real number in [0;1]
range

Googling a little bit, I found an equation which seems to be aplied by
many photo-editor software

(.3*Red) + (.59*Green) + (.11*Blue)= Luminance/brightness

I'm just wondering whether someone here has better ideas...

regards - julian

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