[softwarelist] Re: Calibrating scanner with TWAIN
- From: David Pilling <flist@xxxxxxxxxxxxxxxxxxx>
- To: davidpilling@xxxxxxxxxxxxx
- Date: Thu, 10 Aug 2006 11:55:35 +0100
In message <44DA5FC0.2060701@xxxxxxxxxxxxxxxx>, Michael Ben-Gershon
<mybg@xxxxxxxxxxxxxxxx> writes
Where do I start? I know the screen and printer are calibarted
together, but how do I adjust the scanner?
<sigh> At last someone who would like ICC colour profile support on RISC
OS.
One comment is that the Epson driver lets you pick from a menu a number
of Epson colour corrections - these date back to the earliest Epson
scanners. I'm not sure how useful they are, but perhaps picking the
wrong one might give poor results.
Knowing what I know now (i.e. in the light of profile support in DPScan
and Ovation Pro on Windows) it would be easy to make the TWAIN driver
take in an ICC profile and put out standard sRGB.
It is unlikely I will do any more work though.
Later Epson scanners allow a colour matrix to be uploaded into the
scanner. Perhaps that allows the scanner to do the correction in the ICC
profile and at higher resolution than the 8 bits the driver sees.
I suppose there may be the possibility that the colour matrix is left in
a non-standard state. For some scanners I've heard it said that scanning
from Windows and then RISC OS gives different results to just scanning
from RISC OS from cold.
My TWAIN driver will let you do some colour correction - you can twiddle
the RGB gamma curves independently of the overall brightness. There's
also a detint button to help you set things (scan something white and
then click the button). However this is not going to be fun.
I know there are a handful of 4990 users, how do others go on?
--
David Pilling
email: david@xxxxxxxxxxxxxxxxxxx
web: http://www.davidpilling.net
post: David Pilling P.O. Box 22 Thornton Cleveleys Blackpool. FY5 1LR UK
fax: +44(0)870-0520-941
Other related posts: