Don wrote:
> The number you are reading is the brightness of the spot from 0-255,
> not the density. The density in absolute terms is therefore
> porportional to the inverse of the number, or in density numbers to
> the log(10) of the inverse of the number/255.
Correct. Also, don't forget gamma. This is an exponential funciton applied
to the data before it is displayed. In practical terms this means an image
value of 128 will be somewhat darker than 50% intensty.
You may set a custom working space with a gamma of 1.0 to eliminate this.
--
Mike Russell
http://www.curvemeister.com http://www.zocalo.net/~mgr http://geigy.2y.net