[Openicc] Re: color-policy vs. color-infrastructure

[Graeme Gill]

Lars Borg wrote:
> At 3:06 PM +1100 3/17/05, Graeme Gill wrote:

> How do you obtain an exact inversion? And how does that relate to the 
> gamut?

By representing the colorimetric A2B table in memory, and inverting
each cell (along with the per channel tables etc.). Another way
of putting this is that the A2B table is searched for a device
value that gives the target PCS. If no device value is found,
the PCS must be out of gamut.

If the colorimetric forward table is the definition of the
device response (given that it's the most accurate practical
representation of the devices real behaviour), then this is
an accurate out of gamut check.

Graeme Gill.