Hermann-Josef Röser wrote:
Hi,
Fraser et al. (2005) in their book “Real world color management” confuse me
by contradicting statements: On page 89 they say for the relative
colorimetric intent that “it maps white in the source to white in the
destination. Then it reproduces all the in-gamut colors exactly, and clips
out-of-gamut colors to the closest reproducible hue”. On page 91 they say
that “relative colorimetric rendering scales the source white to the
destination white and adjusts all other colors proportionally”.
So if I render a scanned image with my scanner profile into, say, AdobeRGB,
the relative colorimetric intent adjusts the white point to the white point
of the AdobeRGB space. Then if such an image is displayed on a calibrated
monitor, the AdobeRGB white point is mapped to the monitor’s white point,
according to the settings in the operating system. Default there (Windows)
for images is perceptual, but since AdobeRGB is a matrix profile, this in
fact means relative colorimetric.
Is all this correct or do have misunderstood something?
What does “adjustment of the white point” mean mathematically? How are the
colours transformed? What does “adjust all other colors proportionally”
mean? Proportionally to what?
