Hi, >Dear group, > >I run into small problem with rgb space conversion. Suppose I have RAW >scan of negative. Scanner is very simple for colorimetric >characterization. Now in Photoshop I assigning Ekta Space as a working >space and do negative inversion: curve+levels. Now the result is here >(image converted to sRGB, Adobe CMM, relative, no black point): > >http://main.pam.szczecin.pl/~piotrlg/t/fshop_ekta_srgb.jpg > >This is very hue sensitive picture. Now I understand that Photoshop >did this conversion for me: > >1) RAW RGB >2) XYZ(EktaS chromacities) >3) Chromatic adaptation >4) RGB (sRGB inverse matrix) > >I understand I can do this with LCMS using input space as Ekta and >output as sRGB. Am I right? Unfortunately saturation and hue is >different: > >http://main.pam.szczecin.pl/~piotrlg/t/lcms-ekta-srgb.jpg > >Please tell me what I missing here because I must use LCMS?
At first glance, it seems to me the mistake is in the inversion. Check how you are doing the negative reversing in both workflows, probably you are going across profile chain and then inverting in one path whilst first reversing and then across profiles in the other. This could explain hue shift, due to nonlinearity of gamma curves. Regards, Marti Maria The little cms project http://www.littlecms.com [EMAIL PROTECTED] ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/ _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user
