On 12/5/2016 9:31 PM, clipka wrote:
> Am 06.12.2016 um 03:13 schrieb Mike Horvath:
>> I'm looking at the formulas for CIELUV color space on Wikipedia.
>>
>> https://en.wikipedia.org/wiki/CIELUV
>>
>> The article says, "The quantities u′n and v′n are the (u′, v′)
>> chromaticity coordinates of a "specified white object" – which may be
>> termed the white point – and Yn is its luminance."
>>
>> I have a D65 whitepoint:
>>
>>     #declare XYZWhiteReference = color <95.047,100.000,108.883>;
>>
>> Which of these values is u'n, v'n and Yn?
>
> Neither. Those three values are X, Y and Z, respectively. The formula
> for converting these to u' and v' are given a few lines later in the
> Wikipedia article:
>
>     u' = (4X) / (X + 15Y + 3Z)
>     v' = (9Y) / (X + 15Y + 3Z)
>

Thanks!

Mike

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