I'll probably code a bit less on DCamProf for a period.
The next area to look into I think may be the rendering of very high saturation colors, found in for example flowers. I've noted that it's quite typical to get issues with clipping, the blue range often seems to be the most hurt.
Hi Anders,
Yes, although the clipping will often occur
after White Balancing, while the Raw data is not clipped. Blue can result in underexposure if some flower Reds and Yellows are very pure, and those Reds and can be pushed into clipping depending on the illuminant's color temperature. RawTherapee allows to scale the yet undemosaiced linear gamma Raw data to prevent such issues, but if instead the profile is supposed to adjust for that, then things will get difficult pretty fast.
In theory the raw converter's built-in gamut mapping would handle this, but few raw converters have any gamut mapping at all, and if they have it it's much to simplistic to handle this type of issues well. Commercial bundled profiles generally have gamut mapping built into the profile itself.
Not optimal, but such is life ...
I personally don't shoot these type of subjects much so I need to get to the florist and make some shots so I can investigate this area more.
I have a nice Yellow/Red Raw example for you, which is just 1/3rd stop below saturation clipping of the Raw data and with extremely deep blue channel data bordering on underexposure clipping. I also have some others, all very saturated flowers. I'll PM you a link, if you can use it exclusively for testing, just let me know. I do understand that you'd want to visually compare the original with its rendered version, but I can't arrange that.
Cheers,
Bart