Hi Martin, >What am I missing?
I have tried the conversion with icctrans and the numbers does match CS3 and Bruce Lindbloom's Web site (BTW, this is an outstanding resource, I highly recommended it). Overall it works to me. I wonder why are you getting such values. Using lcms-1.19: $ icctrans -t3 -i*LabD65 LittleCMS ColorSpace conversion calculator - v3.3 Enter values, 'q' to quit L*? 95 a*? 0 b*? -2 R=242.42 G=240.32 B=244.67 Enter values, 'q' to quit L*? 55 a*? -37 b*? -50 R=0.00 G=151.71 B=217.82 Enter values, 'q' to quit L*? 48 a*? 74 b*? -3 R=218.49 G=20.16 B=121.54 Enter values, 'q' to quit L*? 89 a*? -5 b*? 93 R=255.00 G=222.58 B=0.00 Enter values, 'q' to quit L*? 16 a*? 0 b*? 0 R=40.42 G=39.63 B=39.73 Checking with lcms-2.0, I got extra precision and negative numbers, as it can run in unbounded mode. It matches very well CS3 and CS4. $ transicc -t3 -i*LabD65 LittleCMS ColorSpace conversion calculator - 4.0 [LittleCMS 2.00] Enter values, 'q' to quit L*? 95 a*? 0 b*? -2 R=239.2180 G=240.6768 B=244.4407 Enter values, 'q' to quit L*? 55 a*? -37 b*? -50 R=-525.6947 G=151.1227 B=218.0212 Enter values, 'q' to quit L*? 48 a*? 74 b*? -3 R=216.5063 G=11.5710 B=122.5150 Enter values, 'q' to quit L*? 89 a*? -5 b*? 93 R=247.4448 G=224.1414 B=-69.9634 Enter values, 'q' to quit L*? 16 a*? 0 b*? 0 R=39.7596 G=39.7596 B=39.7596 Regards Marti. > Hi > > I'm trying to create a transform of Lab D50 values to sRGB, using > Guy's python bindings and lcms 1.18a. > > import littlecms as lcms > import numpy as np > 48 > # Set white point > D65WhitePoint = lcms.CieColour([95.047, 100.000, 108.883], colourSpace='XYZ') > # Create profile > labD50Profile = lcms.Profile(colourSpace=lcms.PT_Lab) > labD65Profile = lcms.Profile(colourSpace=lcms.PT_Lab, > whitePoint=D65WhitePoint) > sRGBProfile = lcms.Profile(colourSpace=lcms.PT_RGB) > # Create transform > labD50_to_labD65_transform = lcms.Transform(labD50Profile, labD65Profile, > renderingIntent=lcms.INTENT_ABSOLUTE_COLORIMETRIC, inputDepth=0, > outputDepth=0) > labD65_to_sRGB_transform = lcms.Transform(labD65Profile, sRGBProfile, > renderingIntent=lcms.INTENT_ABSOLUTE_COLORIMETRIC, inputDepth=0, > outputDepth=8) > # Colours to be transformed > labD50Colours = np.array([ > [95, 0, -2], > [55, -37, -50], > [48, 74, -3], > [89, -5, 93], > [16, 0, 0] > ], dtype=np.float64) > # Transform colours > labD65Colours = labD50_to_labD65_transform.doTransform(labD50Colours) > sRGBD65Colours = labD65_to_sRGB_transform.doTransform(labD65Colours) > > print sRGBD65Colours > > These are the resulting colours: > [[252 236 212] > [ 0 149 191] > [220 18 106] > [253 220 0] > [ 42 39 34]] > > Now, I expected something like the output from Photoshop and Bruce > Lindblooms converter: > > PS CS3 Abs. col. > 239, 241, 245 > 0, 151, 118 > 216, 11, 122 > 248, 224, 0 > 40, 40, 40 > > Bruce Lindbloom (using Bradford) > 240, 241, 244 > -111, 151, 218 > 216, 11, 123 > 247, 224, -40 > 40, 40, 40 > > What am I missing? > > Martin Weberg > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > Lcms-user mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/lcms-user > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.425 / Virus Database: 270.14.73/2514 - Release Date: 11/19/09 > 19:42:00 > > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Lcms-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lcms-user
