> > I think the non-linearity of "RGB" (most likely LMS) data from sensor must > > be > > compensated before matrix conversion to allow the next conversions to be > > truly additive > > nor multiplicative. Graeme Gill wrote: > It's hard to guess what typical raw tools workflow actually is. Some may > attempt to do white balancing prior to ICC based color space conversion, > although any such variables will tend to invalidate the profile. Personally > I'd be looking at creating a workflow in which the ICC profile > is used to convert the raw input into absolute XYZ space, and > then apply rendering effects such as white balance etc. in XYZ space. > For this purpose, a matrix profile may be a better bet than > typical CLUT profiles, since CLUT profiles may not have the required > accuracy over a raw images full dynamic range. It's exactly what I dream about! You are "hit the mark"! I think the RAW channel data can be linearised equivalently at a stage before conversion to XYZ because of camera design. I suppose there will be enough simple matrix conversion to XYZ after linearisation without any LUT. That profile will be most exact because of it may be physically natural and correct.