Quote:
Originally Posted by zoyd /forum/post/22033219
oh, ok - if you have all the measured and reference locations (and using z=1-x-y) then solve kr and km using eqns. 6 and 7. Then plug the k's into eqns. 1 and 3 and finally solve for R with eqn. 8.
OK, this is my first try with matrix math. Here is what I did.
Instead of just using the xy values for WRGB as measured for the two probes, I 'assumed' the reference probe was at Rec709 spec. I then used the correction I was given to create the WRGB xy values that my probe would measure.
Example: white x correction was .007 and y correction was 0 based on .309/.329 for my D3 and .316/.329 for the reference . So I 'shifted' reference to Rec709 spec and used .313/.329 and for my 'measured' probe I used .306/.329. When my probe reads .306/.329 the white point is actually spot on at .313/.329. I don't know enough about matrix math to know if this creates an error, but since those are actually the measurements that would be obtained, I was thinking it wouldn't matter. It just helped me 'see' what I had to do about my measurements in the matrices.
So, after going through my maiden voyage into matrix math, Google and I came up with this final value for
R. I had some difficulty deciding how to do in Eqn. 8 the ^ -1. The matrix below is based on this interpretation:
R = Nrgb x (Mrgb ^ -1)
and not R = (Nrgb x Mrgb)^ -1
For those who have seen these corrections entered, does this look like a reasonable one given the xy corrections I've already posted for WRGB?
1.024 0.000 0.000
0.000 0.994 0.000
0.000 0.000 0.987