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Re: number of grid points in A2B table



Terry Wyse wrote:
I suppose it's technically possible but perhaps unnecessary. Just guessing here, but perhaps you don't need as many grid points going from the relatively small CMYK and RGB LUT color spaces to the PCS (Lab/XYZ) but you need more grid points going from the relatively large PCS to the device values. That's just a guess and I'm sure Mr. Gill will jump in and correct me if I'm wrong. :-)

Happy to jump in and confirm that you're right :-) Resolutions are usually a time/space trade-off with quality. The LUT tables are (resolution) to the power number of (channels), so CMYK A2B tends to blow up pretty fast with increasing resolution, while RGB A2B is a bit slower. Because the B2A table is also 3 channel (XYZ or Lab), it can afford a higher resolution, and it generally needs it, because the gamut of usable colors is generally a small percentage of the grid count in Lab or XYZ space.

Graeme Gill.
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 >Re: number of grid points in A2B table (From: Terry Wyse <email@hidden>)



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