Re: a colorspace quandry
Re: a colorspace quandry
- Subject: Re: a colorspace quandry
- From: Bob Smith <email@hidden>
- Date: Sat, 14 Apr 2001 15:14:09 -0500
Doug Brightwell wrote:
>
1. The actually CCD chip sees a huge color space, much bigger than the
>
scanner profile...
No, the scanner profile describes the performance of the CCD and its related
circuitry that transforms its analog signals to digital data. A scanner
profile is a source. Data is not being moved to it. Its describing the
characteristics of data coming from a particular device
>
If converted to Ekta Space, it's being moved into a larger color space where
>
there is enough "room" that there's no need to be mushing the color values
>
around. The conversion should be ideally relative colormetric so as to simply
>
port the color values over unchanged
if the source space is smaller than the destination space, the a relative
colorimetric transform and a perceptual transform should yield the same
results. Perceptual transforms will squeeze data down from a larger space
to maintain color relationships in a smaller space. It won't expand data
when moving to a larger space.
>
4. PS 6 allows LUT profiles to serve as working spaces, and that opens up
>
possibilities for new working space profiles that Joe Holmes and you (Jon)
>
have developed.
That means its possible to use your scanner profile as an editing space. I
wouldn't recommend it because its probably not uniform (r=g=b is not neutral
throughout the space, making editing by numbers a bit tricky). Where this
is helpful is that if you open a file into Photoshop 6 that has your scanner
profile embedded, it will be displayed properly. You don't have to convert
to a working space just to have the image properly displayed on you monitor.
You did have to do that in Photoshop 5. This makes it a bit more practical
in some work flows to just tag files coming off the scanner with the scanner
profile and worry about how best to edit them later.
Bob Smith