QTR-Quadtone RIP

> From: Roy Harrington
>
> The nice thing about using Lab is that the ideal values just a
> straightline.
> The L values are exactly what QTR linearizes to.  Densities are a
> more complicated
> function.
>
> If you do want to convert so you can compare dMax etc. these are
> the formulas:
>
> first compute Y = luminance
> Y = L/903.2               if L < 8
> Y = ((L+16)/116)^3   if L >=8
>
> second compute d = density
> d = -log(Y)
>
> typical whites are around L=95 to L=97
> typical blacks on matte paper are around L=14 to L=17
>   on photo paper more like L=4 to L=8

Or, just go to
<http://www.brucelindbloom.com/index.html?CompandCalculator.html> and let
the machine do it.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...