"scott" <sco### [at] scottcom> schreef in bericht 
news:4b13a82f$1@news.povray.org...
> You do realise that photos are usually in sRGB colour space and POV 
> expects linear colour values?  By simply pasting the numbers into POV the 
> colours in the resulting image are going to be washed out and probably of 
> the incorrect hue...
>
> Better to do a simple inverse gamma correction inside POV (the 2.2 here 
> roughly approximates the sRGB -> linear conversion):
>
> rgb <pow(128/255,2.2),pow(96/255,2.2),pow(250/255,2.2)>
>
> That way the colours in your POV output image should match much better 
> what you picked in the first place.
>

This may even be true (in my experience) with any color picker external to 
POV-Ray. Bearing that in mind, I wrote a little macro using your line of 
code:

#macro ColorCorrect(ColorIn)
  rgb <pow(ColorIn.red/255, 2.2), pow(ColorIn.green/255, 2.2), 
pow(ColorIn.blue/255, 2.2)>
#end

Which you can use then whenever you pick an external color, e.g.:

#declare ColorIn = <0.0,  128,  128>; //the color picked externally
sphere {
  0.0, 1
  texture {
    pigment {ColorCorrect(ColorIn) }
    finish{
      specular 0.2
      roughness 0.001
    }
  }
}

Thomas

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