Last week, Patel took a test strip of galaxy prints made with different RGB-to-CMYK conversions for C-printing and we analyzed the results. Today I used the results of that to make a refined test print, with a finer grid centered on the best results from last week's test. The idea is to do a RGB-to-CMYK conversion that respects the physical properties of the CMYK inks, such that the reflectance of the CMYK print is related in a sensible way to the intensity of the RGB image on a standard monitor. Or, another way to put it: RGB is a light-emission standard, CMYK is a light-absorption standard. The light-emission and light-absorption mechanisms are imperfect, but in ways that can be modeled. We should use that! This all in preparation for the Atlas.
In related news, Patel and Mykytyn visited Princeton to meet Lang today, and Mykytyn got the star masking working in our Tractor fits of very bright galaxies. All this bodes well for our photometry and sample selection of the brightest galaxies in the SDSS footprint.
"The idea is to do a RGB-to-CMYK conversion that respects the physical properties of the CMYK inks, such that the reflectance of the CMYK print is related in a sensible way to the intensity of the RGB image on a standard monitor."
ReplyDeleteInteresting… though I'd worry you might end up re-inventing the wheel, given that this is a problem the publishing industry has been dealing with since at least the early 90s. (Of course, not all of their solutions are necessarily affordable.)