I want to create icc and or dcp profiles for use with Lightroom in particular. Unfortunately, it's not clear to me at what exact state of development LR applies a profile and hopefully, that same state LR uses can be replicated using LibRaw?
I'd also like to test and or compare the result of applying the newly created profile via LR to some other mean of applying the profile, especially in the case of dcp profiles. Any suggestion?
Lightroom does not utilize
Lightroom does not utilize ICC profiles for camera color calibration. It only accepts DCP.
ICC and DCP profiles are similar, but DCPs can be more sophisticated. I'm going to quote from the dcamprof documentation (open source command line utility for making color profiles)
"The forward matrix which operates in D50 XYZ space using D50 as the reference illuminant is not unique to DNG profiles, it’s used for ICC profiles too."
"The color matrix is... DNG-specific, it’s used for estimating the temperature and tint of the scene illuminant based on a white balance setting."
Both ICC profiles and DCP profiles can contain LUTs. These are color look up tables.
DCP profiles can contain two types: HueSatMap tables and LookTables. HSM tables basically do additional color correction. LookTables apply a second set of adjustments on top of that. Sometimes there is only an HSM or LookTable. Sometimes there is also only a color matrix in DCPs. They can be designed in a nubmer of ways.
If you want to experiment with making your own color profiles, download dcamprof, rawtherapee, buy a color checker, and follow these instructions https://rawpedia.rawtherapee.com/How_to_create_DCP_color_profiles