Re: LAB as working/interchange space
Re: LAB as working/interchange space
- Subject: Re: LAB as working/interchange space
- From: Chris Murphy <email@hidden>
- Date: Thu, 24 May 2001 00:49:00 -0600
Chris Cox writes:
>
16 million colors in 8 bit/channel sRGB will transform to only 2.47
>
million colors in 8 bit/channel LAB (without dithering).
and
>
But if you look into
>
the details at all, you quickly find that LAB is not a great
>
representation for your image data. It's a nice mathematical
>
construct for interchanging data -- but whenever you use LAB you have
>
to keep around extra bits of precision to maintain image quality.
Why is it that I can take a wide variety of RGB images defined with
Adobe RGB, convert them to Lab, then take the Lab set of images and the
RGB set of images - and convert them properly from their respective
source to a destination using a suitable output device profile - and end
up with visually the same thing? From inkjets to printing presses, I
don't see the decrease in image quality.
I have no doubt what you're saying is true, I'm just wondering to what
degree this actually affects the reproducibility of images? In what
respects should I be seeing image degradation just by converting a good
RGB image into 8-bit/channel Lab?
Chris Murphy
Color Remedies (tm)
Boulder, CO
303-415-9932