Re: RGB to L*a*b* conversion

Posted by Duane and Julie on
URL: http://imagej.273.s1.nabble.com/RGB-to-L-a-b-Conversion-tp3703729p3703732.html

Michael,

I agree that sRGB has a smaller gamut, but you deal with what you've  
got.  :-)  I picked sRGB as my uncalibrated space because it's the  
only one where we know the phosphors.  It's also more prevalent  
nowadays.  You will note in the code I posted that I actually convert  
to XYZ from whatever and then on to whatever is requested.  The  
problem is, when's the last time you found a camera that put out XYZ?

    duane

On Feb 11, 2006, at 4:45 PM, michael shaffer wrote:

>  Duane writes ...
>
>> RGB is an uncalibrated space, L*a*b* is a calibrated space.
>> That said, if you assume the RGB to really be sRGB you can do
>> a conversion that is probably what you want, or close to it.
>>
>> I wrote a color space converter, [...]
>
>   Given that sRGB is a much smaller gamut than L*a*b ... It  
> wouldn't be much
> more difficult to convert from one of the larger gamut color  
> spaces ...
> e.g., ProPhoto.  Granted, there are few devices that can take  
> advantage of
> large gamut color spaces, but sRGB (... A de facto monitor  
> standard ...)
> seems too small to be worthy of a conversion to L*a*b.
>
>   ... Just a suggestion ...
>
> Genuinely, Michael Shaffer  :o)
>
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