Originally Posted by DigitalFilm
Not related, no - but I am genuinely interested in how having more points needs less accuracy in the final point calibration.
A valid question I would suggest?
In a statistical problem like this you can decrease the precision on each measurement as you increase the number of measurements and still arrive at the same mean error. There is nothing special about that.
As for LightSpace thread, I agree with the granularity concept, and it seems the tests Buzz has done also suggest there is something in that.
Makes sense to me. Does it not to you?
Of course it makes sense, but higher inefficient
granularity is just dumb. You can achieve the same mean error using 17^3 grid points as using 1500 points optimized using the geodesic algorithms present in ArgyllCMS.
And the reason for the threads posted in is my interest in in 3D LUT calibration only - not in other approaches.
There is some new 3D LUT hardware coming to market, and that's my real interest.
ArgyllCMS is a 3DLUT approach, equivalent in it's math to both CalMAN and LightSpace, performs just as well, has the additional capability of doing CIECAM02 appearance matching, and it's free. The .icm profiles it uses to link source and target color spaces are just a data path for exactly the same XYZ measurements and manipulations that LightSpace uses.Edited by zoyd - 3/29/13 at 9:17am