It's hard to make definitive statements about perceptual rendering, because this is really where profiling tools differentiate themselves -- each one has it's own secret sauce.
Generally, there's some weighting -- it isn't just a linear desaturation -- and in-gamut colors typically get less desaturation than out-of-gamut ones.
The effect is usually quite subtle because our eyes tend to judge relative color, rather than absolute, and because if you're making the judgements on the monitor, what you're looking at is pretty close to sRGB anyway.
I'm trying to find out what happened to part II of sharpening -- it was here, but it seems to have dropped off the list on my author's page. I've sent the appropriate inquiries to teh appropriate powers...
Submitted by BruceFraser99 on Sat, 04/14/2001 - 15:22.
Your description of perceptual rendering, which is to essentially move all RGB values into gamut, might seem to imply more desaturation than we actually see. That is, we might expect extreme desaturation if we move from ProPhotoRGB to sRGB ... and less if from ProPhoto to AdobeRGB. While I watch for this, I seem to experience it only very subtly, if at all. I wonder if this might be because the perceptual rendering process is somehow weighted, or if some aspect of gamut is given special consideration. How does this work?
shAf
(P.S., isn't there a second article on sharpening which should be on your list of fine articles?)
Perceptual rendering
Michael,
It's hard to make definitive statements about perceptual rendering, because this is really where profiling tools differentiate themselves -- each one has it's own secret sauce.
Generally, there's some weighting -- it isn't just a linear desaturation -- and in-gamut colors typically get less desaturation than out-of-gamut ones.
The effect is usually quite subtle because our eyes tend to judge relative color, rather than absolute, and because if you're making the judgements on the monitor, what you're looking at is pretty close to sRGB anyway.
I'm trying to find out what happened to part II of sharpening -- it was here, but it seems to have dropped off the list on my author's page. I've sent the appropriate inquiries to teh appropriate powers...
is perceptual rendering as simple as that?
Your description of perceptual rendering, which is to essentially move all RGB values into gamut, might seem to imply more desaturation than we actually see. That is, we might expect extreme desaturation if we move from ProPhotoRGB to sRGB ... and less if from ProPhoto to AdobeRGB. While I watch for this, I seem to experience it only very subtly, if at all. I wonder if this might be because the perceptual rendering process is somehow weighted, or if some aspect of gamut is given special consideration. How does this work?
shAf
(P.S., isn't there a second article on sharpening which should be on your list of fine articles?)
question
is there a way to check in photoshop what rendering intent is used in an image with an embedded profile?