Hi Marti, I tried you suggestion and the profile seems fine:
These are the result of 9 Lab colours, converted to output profile and back, using absolute colorimetry: Lab in RGB out Back to Lab 10 0 0 0 17 1 12.6 0.5 -3.6 41.1 65.8 38.5 205 2 12 43.5 63.7 37.4 85.5 0.3 84.8 252 244 18 85.3 0.2 84.8 47.6 -49 28.1 17 156 24 48.2 -49.7 28.5 50 0 0 93 110 103 50 -0.3 -0.1 31 -0.7 -43.9 23 62 145 30.4 1.4 -49.7 39.9 53.4 -32.1 168 25 195 39.8 53.9 -34.2 53.1 -34 -20.6 23 176 165 53 -35 -19.7 93 1 -8.5 253 255 254 92.7 0.8 -8.7 This is nice :) However, how do I know, from the profile, what the whitepoint and blackpoint values really are? OK, I just read it in the docs, I will give it a try... And, thanks for version 1.14, it is running fine! Greetings, Auke > Auke: > > This may be due to several reasons. I want to first check the accuracy > of your profile to know where the problem actually is. So, the way to > check > the accuracy of your profile is to use absolute colorimetric. If this > works, > then rel. colorimetric is going to work too. But since rel. colorimetric > implies a white point translation, there is no direct way to measure it. > > So, I proposed to use a transform between Lab -> printer profile because > Lab identity is operating on D50. It is not same as using AdobeRGB as > input profile. > > At that point abs. colorimetric should work. If not, the profile is not > proper > and you cannot obtain any further improvement. > >>c. I don't *wan*t to use absolute colorimetry as it changes the RGB >> values >>too much. For instance white (Lab 100,0,0) is trnaformed to 229,246,255. >>If I print this, I don't get paper white anymore, yet my paper is >> becoming >>even more blue :( > > But your unprinted paper is not of Lab=(100, 0, 0) right? Try to measure > your > unprinted paper and feed such value to the abs. colorimetric transform. It > should > give you a (255, 255, 255) or something really close to that. > > Regards, > Marti. ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user
