Hello Oliver, Tried, and it works quite well to me.
I have converted the JPEG to TIFF in order to avoid compression artifacts. I'm also using AdobeRGB as source space because the JPEG has no embedded profile. The procedure is to convert the file to UPLab and then back to aRGB. Intent is relative colorimetric. tifficc -t1 -w16 -o AdobeRGB1998.icc -o CIELab_to_UPLab2.icc StdVsUPLab.tif UPLab2.tif tifficc -t1 -e -i CIELab_to_UPLab2.icc -o AdobeRGB1998.icc UPLab2.tif adobe.tif Please note I'm using 16 bit intermediate storage. Alas, the profile has some error, if you try the ICC tool (http://color.org/wxProfileDump.zip) you got Round Trip 1 ------------ Min DeltaE: 0.00 Mean DeltaE: 1.73 Max DeltaE: 26.43 Which is consistent to what you get if you use tiffdiff in the image tiffdiff -o a.tif adobe.tif StdVsUPLab.tif Digital counts 99.832% equal. mean 0.428416, min 0, max 13.8564, Std 1.03271 dE Colorimetric 99.8939% equal. mean 0.270681, min 0, max 3.13803, Std 0.402988 In any case I cannot see big diferences like those in your sample image. Make sure to use the UPLab profile with correct tag directions (CIELab_to_UPLab2.icc), as Bruce already states in his website. Regards Marti Maria The LittleCMS project Oliver Duis <od...@hotmail.com> escribió: > Hello, > > > > I'm trying to get UPLab up and running: > > http://brucelindbloom.com/index.html?UPLab.html > > using the LCMS compatible ICC profile version (see page down below). > > > > If I just transform twice, an empty round trip Lab>UPLab>Lab, in > float mode, I'd expect the colors not to change as long as there are > no challenging gamuts. > > However the greens are a little bit washed out and especially on > pink color gets pretty desaturated: > > http://www.visualbakery.com/RawTherapee/Download/StdVsUPLab.jpg > > (watch the pink with the leaves on it on the circle) > > > > I already tried the Lab2 vs. Lab4 functions and several intents, no help. > > > > My first guess would be that there is some trouble with a LUT point? > > > > Thanks in advance > > Oliver > > > > ------------------------------------------------------------------------------ Better than sec? Nothing is better than sec when it comes to monitoring Big Data applications. Try Boundary one-second resolution app monitoring today. Free. http://p.sf.net/sfu/Boundary-dev2dev _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
