On Sat, Nov 15, 2008 at 3:38 PM, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote: > Pascal de Bruijn wrote: >> >> I'm trying to create an ICC profile which imitates to color >> transformation done by my camera. > > I'm not sure what you mean by that. Do you mean you are > trying to profile your camera ? Yes, but not in the normal way. Normally profiling a camera would mean you're making a profile faithfully reproduce accurate colors. At least for this experiment, that's not my intention. My camera, does internally apply a color conversion. Which I can't seem to be able to reproduce. So I'm trying to abuse ICC profiles for that. I want to "profile" the difference, between my raw (developed liniearly), and the JPG produced by my camera. >> So I photographed an IT8 target, in RAW+JPG mode. Then I developed the >> raw with UFRaw, > > Note that any "development" through a raw converted needs > to be kept constant for the profile to remain valid. Of course. >> and converted to JPG to TIF with GIMP: >> >> scanin -p -v -dipn -o IMG_4438_JPG.tif it8.cht > > This merely gets the RGB values from the image. I'm > not sure why you are doing this given that the next command > does the same thing as part of assembling a .ti3 file. > >> scanin -p -v -dipn IMG_4438.tif it8.cht IMG_4438_JPG.val > > This won't work. You need to provide the IT8 CIE reference values, > the values measured from your IT8 chart with an instrument either > by yourself, or provided by the manufacturer of the IT8 chart. Like I said, I don't want to use the manufacturer data as a reference. But the JPG the camera produced. > A profile provides a model of a devices color behaviour, > connecting the device values with the device independent > CIE standard observer values. For an input device this > means that two sets of information are needed for each patch, > one being the CIE values for the patch, and the other being > the device RGB values. scanin retrieves the latter from the raster file, > and combines them with the CIE values you have to provide. The RGB > values you have extracted from the raster file is not a source of > these values. I'm aware I'm abusing ICC in an unusual way. But is there a way to make this work? Regards, Pascal de Bruijn