This is very much a imaging question, but Photography looked like the best site to ask.
I've been reading information about ICC, color spaces, JPEG metadata, and the like trying to understand this.
When an application 'embeds' a color/ICC profile into an image, like a JPEG, does that actually embed the entire ICC Profile? If I saved a photo with the sRGB or Adobe RGB color profiles embedded, does that mean color-aware applications will:
- Open the image
- Extract the profile data (i.e. it sees the image is AdobeRGB)
- Apply transformations on the color using the information from the profile
- Display the image
My confusion comes from inspecting a bunch of photos I have - I viewed their metadata with exiftool, and this snippet of information came out:
Color Space : sRGB Profile CMM Type : Lino Profile Version : 2.1.0 Profile Class : Display Device Profile Color Space Data : RGB CMM Flags : Not Embedded, Independent <--- does anything use this? Device Manufacturer : IEC Device Model : sRGB Device Attributes : Reflective, Glossy, Positive, Color Rendering Intent : Perceptual Connection Space Illuminant : 0.9642 1 0.82491 Profile Description : sRGB IEC61966-2.1 Device Mfg Desc : IEC http://www.iec.ch Device Model Desc : IEC 61966-2.1 Default RGB colour space - sRGB
So this photo has an sRGB profile, that's fine. But what is the CMM Flags field for and does anyone use it?
The ICC standard, in section 7.2.11, says the CMM field data indicates this this:
The profile flags field shall contain flags to indicate various hints for the CMM such as distributed processing and caching options
Position 0 -
Embedded profile (0 if not embedded, 1 if embedded in file)
Position 1 -
Profile cannot be used independently of the embedded color data
So condensed to a couple related questions:
Does embedding an ICC profile into an image actually embed the entirety of that profile into an image? Or does it only serve to tell color-aware applications to look for that profile in the system (i.e. Windows' ICC directory)
Am I just confused and the CMM Flags are independent of the notion of embedding an ICC profile?
Thanks, I hope my question is clear enough.