Adjust color temperature

Hi!



Does anybody know, how exactly programs like Camera Raw or Lightroom shift the overall color temperature of an image?



As far as I understand it, this adjustment if -of course- not made in the RGB space. So I transform the image to CIE XYZ.



I already tried to achieve the temperature shift by simply using a different white-point (according to Placks black radiator) when converting back to RGB. This method works, but this doesn't look exactly like what Lightroom is doing.



Any help would be highly appreciated!

Michael
Adjust color temperature
A temp shift depends on two parameters, the original reference whitepoint and the shift. The original whitepoint may be a device whitepoint which may not be the same as the RGB working-space whitepoint or whatever you take as the reference.



And the adjustment can best be done in a specific RGB space as opposed to XYZ. You should be looking for a Bradford transformation which is really like using an RGB space.



Also, an image for which you don't have the original linear capture data might be impossible to correctly adjust for colortemperature shifts. So make sure you compare apples to apples if you compare to the Adobe transformations.