Re: Scanning with USM or not?
Re: Scanning with USM or not?
- Subject: Re: Scanning with USM or not?
- From: Henrik Holmegaard <email@hidden>
- Date: Sat, 2 Jun 2001 10:25:09 +0200
email@hidden (Lee Blevins) wrote:
Some high end CMYK Drum scanners offer RGB scanning but it's really just
a conversion to RGB after the CMYK image is made.
Our DS scanner does this.
Since USM is only applicable in CMYK, this is a tipoff that you're
scanning cmyk and having it converted to rgb.
Hmm...in other words a specific model of Screen scanner which uses
device links (older firmware RGB to CMYK tables) only applies USM to
CMYK. From this I'd say it doesn't follow that USM is only applicable
to CMYK.
(And as I'm just as ignorant of other products as the next person,
then best I add that the following is true of Linocolor as scanner
software -:).)
If you like, you can apply USM to three channel spaces in the scanner
process. Either in the scanner hardware (starting with mid-range CCD
scanners and going up to the drums) or in the software filters, if
you scan with hardware sharpening off.
Then you can batch the three channel stuff and autoapply USM, just as
you can batch and autoproof, batch and autoseparate to disk, batch
and autoprint ... and so forth.
But the reason not to apply USM to three channel finescans (whether
in the scanner software or in Pshop) is that later compression with
JPEG just might introduce artifacting, and that in a late binding
workflow USM makes images look ugly as sin for folks not always bent
on slapping those images on a press -:).
--
Henrik Holmegaard
TechWrite, Denmark