[Lcms-user] Adobe1998 > PCS LAB

[Glenn Wilton]

Hi All   Im having a little trouble trying to get the results of LittleCMS to Match the PCS colours reported on our Postscript RIP (using ICM2).   Im trying to get the equlivent Adobe1998 -> PCS LAB values from LittleCMS. I can get the same results to the RIP in PhotoShop by changing the settngs to from ACE to Windows ICM and Absolute Colourmetric   What Im getting with photoshop and the RIP via Windows ICM are:   RGB(255, 255, 255) => LAB( 100,-2,-19) RGB(36, 56, 130) => LAB( 24,13,-61) RGB(83, 66, 14) => LAB( 29, 6, 35) RGB(255,255,0) => LAB(98,-19,95)   However in LittleCMS Im getting these results by using the built in LAB profile : hProfileLab = cmsCreateLabProfile(Null)  // Using 16 Bits and D50 same as PCS hProfileAdobe = cmsGetColorSpace("Adobe1998.icm")  // Using 8 Bits hTransform = hTransform = cmsCreateTransform(hProfileAdobe , InputType, hProfileLab , OutputType,INTENT_ABSOLUTE_COLORIMETRIC , cmsFLAGS_NOTPRECALC)   RGB(255, 255, 255) => LAB( 100,-9,-19)  - SAME - RGB(36, 56, 130) => LAB( 24,18,-60) - DIFFERENT - RGB(83, 66, 14) => LAB( 29, 3, 35) - DIFFERENT- RGB(255,255,0) => LAB(97,-25,96) - DIFFERENT -   Can anybody explain this? ... Am I either missing a whitepoint or Gamma??? Glenn Wilton > [EMAIL PROTECTED] <     Glenn Wilton