So I moved upstream and asked about this on the LittleCMS mailing list. From what the users and devs there were able to figure out, there is no ICC profile embedded in my camera's JPG and TIF files. In fact, DSLR cameras do not embed an ICC profile at all. The Digital Camera File system (DCF) specification explicitly states that color profile information should be specified as part of the EXIF metadata. There's a whole series of tags in a digital camera's file which defines which colorspace should be used to interpret it. It's not just "ColorSpace", but others as well all taken together.
So again, this goes back to the application level, and not the color management library. If the application (in this case Gimp) was properly DCF-aware, then it would detect the proper color profile that's specified in the image file. So... is this the right mailing list for this discussion, or do I need to subscribe to the Dev mailing list? Here are the relevant emails from the LittleCMS mailing list. On Sun, Jan 17, 2010 at 7:32 AM, Larry Reeve <la...@polybytes.com> wrote: > The first image is in "DCF Colorspace". This can be seen from the following > entries in the EXIF: > > Color Space: Uncalibrated > WhitePoint X: 0.31 > WhitePoint Y: 0.33 > Chromaticity Red(X): 0.64 > Chromaticity Red(Y): 0.33 > Chromaticity Green(X): 0.21 > Chromaticity Green(Y): 0.71 > Chromaticity Blue(X): 0.15 > Chromaticity Blue(Y): 0.06 > YCbCrCoefficient 1: 0.30 > YCbCrCoefficient 2: 0.59 > YCbCrCoefficient 3: 0.11 > > A DCF aware application sees this information and processes the image > accordingly (which means use an Adobe RGB profile). On Sun, Jan 17, 2010 at 5:03 PM, Larry Reeve <la...@polybytes.com> wrote: > LCMS does not have anything to do with the color space defined in the EXIF > block of a JPEG file. There is no embedded profile. It is up to the > application using LCMS to evaluate the color space definitions in the EXIF > and take the action to load and use an Adobe RGB profile if it is needed. > The DCF Optional Color Space (see paragraph 6.2 of of JEITA CP-3461 "Design > rule for Camera File system DCF Version 2.0") defines the values that should > alert an application to take this action: > > Color Space: Uncalibrated > WhitePoint X: 0.31 > WhitePoint Y: 0.33 > Chromaticity Red(X): 0.64 > Chromaticity Red(Y): 0.33 > Chromaticity Green(X): 0.21 > Chromaticity Green(Y): 0.71 > Chromaticity Blue(X): 0.15 > Chromaticity Blue(Y): 0.06 > YCbCrCoefficient 1: 0.30 > YCbCrCoefficient 2: 0.59 > YCbCrCoefficient 3: 0.11 -- Frank Gore Project Manager www.projectpontiac.com _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
