Re: LAB values
Re: LAB values
- Subject: Re: LAB values
- From: bruce fraser <email@hidden>
- Date: Fri, 1 Aug 2003 16:18:55 -0700
At 12:19 AM +0200 8/2/03, Peter Baumbach wrote:
When I followed the input profile evaluating procedure outlined in Real
World Color Management pp. 224-233 the LAB values of the simulated scanning
result in ColorLab (RGB values built by hand, capture profile assigned, then
converted to LAB with absolute colorimetric as rendering intent) and the LAB
values of the real scanned tiff file with the capture profile assigned in
Photoshop differ.
I don't understand why ?
Because the capture profile isn't perfect (or you made a booboo in
the handbuilding). The differences shown in the comparison between
predicted and actual LAB values on p 230 are better than most, and
are the product of doing many such comparisons to find the "ideal"
scanner gamma (which in this particular case, on my Flextight 848,
was gamma=3.0). An average delta-e of around 1.3-1.8 is fairly
typical. If the average is a whole lot worse than that, let me know.
Bruce
--
email@hidden
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.
| References: | |
| | >LAB values (From: "Peter Baumbach" <email@hidden>) |