robert@xxxxxxxxxxxxxxxxxx wrote: Hi, > Well that has finally clarified that point for me! So with Perceptual the > whole source gamut is squashed down to the destination gamut, even if all > the colors are within the destination gamut. Well, it depends on how you do it. By default the source gamut will be assumed to be that of the encoding space. But you can override this with something more precise. ie. "colprof -g src.gam" or "collink -G src.gam" etc. > This means that in a > Perceptual mapping from ProPhoto to print, colors will be compressed > resulting in desaturation of the image, particularly of the more saturated > colors nearer the print gamut boundary. Yes. > So the following strategy might make sense for a Relative intent conversion: > - Going from ProPhoto to print, make sure the colors are more or less within > the destination space to avoid too much clipping. Yes, one approach is to manually gamut map in some way, and then use a colorimetric conversion. In some cases a small amount of clipping provides the "look" people are after by maintaining saturation, rather than compressing to maintain the space for colors that may not be subjectively so important. (This is a crude way of determining the "knee" in the compression curve.) > And the following for Perceptual: > - Do a Relative conversion from ProPhoto to AdobeRGB (making sure the colors > are more or less within the AdobeRGB space before the conversion to avoid > too much clipping). > - Do a Perceptual mapping from AdobeRGB to print. Yes, that's one way. Another is to feed in a smaller gamut as the source into colorpof/collink -g. The smaller gamut could be from a colorspace (iccgamut) or from the images themselves (tiffgamut). > What would be nice would be to be able to make the smaller intermediate > working color space using tiffgamut/colprof (from a range of typical > images), but I don't see how that could be done. I don't see why you would want to use the 2 step process, when a 1 step with a smaller source gamut specified is more efficient. Graeme Gill.