Ah, I just noticed one thing after hitting send. It looks like the information contained in "extra" channels is lost. So converting RGBA -> LabA -> RGBA I loose the Alpha channel.
Would be great if LCMS could just silently copy extra channels. Best regards Mark On 31.05.2010, at 11:38, marti.ma...@littlecms.com wrote: > > Hi Mark, > > Fixed in git. I have also added Lab+alpha formatters to > lcms2.h default list. > > Regards > Marti > > > Quoting Mark <d...@cine-scan.com>: > >> Great, many thanks! >> >> >> BTW: >> I'm just in the middle of updating some Cocoa wrapper classes to use LCMS >> 2.0. >> Since the "internals" of LCMS changed a lot from 1.x to 2.x some refactoring >> is needed. >> >> But the new concept of Pipelines is awesome! >> >> Thank's a lot Marti. This is an awesome library. >> >> Best regards >> Mark >> >> >> On 29.05.2010, at 15:57, marti.ma...@littlecms.com wrote: >> >>> >>> Hi Mark, >>> >>> I see. The formatter selection code does revert >>> your types to the generic formatter instead of >>> using the Lab template. As a result Lab space >>> is encoded in range 0..1.0 instead of 0..100, >>> -127...+128. >>> >>> Ok, it may be regarded as a bug, and I have it >>> already fixed. Will commit the changes on git >>> probably on monday, as right now the server >>> where I keep the sandbox is down. >>> >>> Thanks for reporting. >>> Marti >>> >>> >>> >>> Quoting Mark <d...@cine-scan.com>: >>> >>>> Hi, >>>> >>>> I'd like to use 16 byte float pixels for RGA, Lab and XYZ conversions - so >>>> I tried defining these: >>>> >>>> #define TYPE_XYZA_FLT >>>> (FLOAT_SH(1)|COLORSPACE_SH(PT_XYZ)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(4)) >>>> #define TYPE_LabA_FLT >>>> (FLOAT_SH(1)|COLORSPACE_SH(PT_Lab)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(4)) >>>> #define TYPE_RGBA_FLT >>>> (FLOAT_SH(1)|COLORSPACE_SH(PT_RGB)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(4)) >>>> >>>> But it looks like something is wrong. >>>> >>>> Using the LCMS built in formats (TYPE_RGB_FLT, TYPE_XYZ_FLT, TYPE_Lab_FLT) >>>> I get the following: >>>> >>>> sRGB -> XYZ -> sRGB >>>> 1.000000, 1.000000, 1.000000 >>>> 0.964200, 1.000000, 0.824900 >>>> 1.000000, 1.000000, 1.000000 >>>> >>>> sRGB -> Lab -> sRGB >>>> 1.000000, 1.000000, 1.000000 >>>> 100.000000, 0.000008, -0.000008 >>>> 1.000000, 1.000000, 1.000000 >>>> >>>> Lab -> XYZ -> Lab >>>> 100.000000, 0.000000, 0.000000 >>>> 0.964200, 1.000000, 0.824900 >>>> 100.000000, 0.000008, 0.000008 >>>> >>>> >>>> Using the formats I defined (TYPE_XYZA_FLT, TYPE_LabA_FLT, TYPE_RGBA_FLT): >>>> >>>> sRGB -> XYZ -> sRGB >>>> 1.000000, 1.000000, 1.000000, 0.000000 >>>> 0.482107, 0.500008, 0.412456, 0.000000 >>>> 1.000000, 1.000000, 1.000000, 0.000000 >>>> >>>> sRGB -> Lab -> sRGB >>>> 1.000000, 1.000000, 1.000000, 0.000000 >>>> 1.000000, 0.501961, 0.501961, 0.000000 >>>> 1.000000, 1.000000, 1.000000, 0.000000 >>>> >>>> Lab -> XYZ -> Lab >>>> 100.000000, 0.000000, 0.000000, 0.000000 >>>> 307598.437500, 321873.781250, 271461.625000, 0.000000 >>>> 100.000000, -0.000001, 0.000000, 0.000000 >>>> >>>> Any ideas what I'm doing wrong? >>>> >>>> Thanks >>>> Mark >>>> >>>> >>>> >>> >>> >> >> >> ------------------------------------------------------------------------------ >> >> _______________________________________________ >> Lcms-user mailing list >> Lcms-user@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/lcms-user >> > > ------------------------------------------------------------------------------ _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
