googleboy said:
I am having a bitch of a time... Partly because I am a bit anal about
getting things right, and I think my equipment is a bit deficient.
I have tried a mustek 1200 ub plus and a canon n670u. Both of these
seem to have an odd problem.
Can't comment on your equipment.
They don't seem to be quite properly square.
I put in a book, scan the cover, and the text is slightly off level. I
even tried doing things like using a metal rule in teh scanner to push
the book closer to the middle of the glass.
So I have to spend ages and ages adjusting the book ever so slightly
trying to get it right.
It's close to impossible to get a scan that's perfectly parallel to the
image borders. If it really matters, perhaps you could find something
solid with a perfect right angle (a carpenter's square?), experiment
until you have it lined up properly, then attach it firmly over the
scanning area. Then you can line up the book against the square
instead of the edges of the case. That's assuming the text is
perfectly parallel to the book's edges.
For post-scan processing, the Windows-only image editors Corel Paint
Shop Pro and Ulead PhotoImpact have a very handy "straighten" tool that
works by having you align two points of a line along what ought to be a
horizontal line in your image. Takes away the guesswork. I couldn't
find a Photoshop Elements equivalent ("Straighten" made a mess of
things), but that program offers a real-time rotation tool that you
could use to eyeball the horizontal line as you adjust it. Note that
PSP, PI, and PE prior to v.3 are limited in their handling of color
managment and 16-bit-per-channel/48-bit/high bit depth images...if you
use them, try to feed them 8-bpc/24-bit images that have already been
converted to a color space (such as sRGB or AdobeRGB). There are
undoubtedly other image editors that offer similar straighten tools.
Second issue I have is the colours that I get back. Most of these
books are extremely spartan in their cover design. Nothing but a big
title on the front, a blurb on the back, a bar code all on a plain
solid single colour background.
What I get back in my scan is usually hundreds of colours, that
altogether may or may not approximate the colour of the book.
By "hundreds of colors," do you mean that you get some sort of unusual
pattern, a rainbow effect, or just more pixel-to-pixel variance within
a color range than you expected? If the former, it could be the moire
pattern Don suggested. If you scan at full DPI, or perhaps take a
magnifying glass to the cover, do you see any sort of fine line detail
that might be getting mushed together at your final DPI setting? Think
of it as similar to a split-second snapshot of the "motion" you see
when you look at a tiny barcode pattern. Remember that the scanner
will see the cover's *texture* as part of the 2D final image--texture
patterns count too. The solution for moire would be to scan at higher
DPI and apply a descreen filter in the scanner software or an image
editor, or apply a moire filter (PSP has one, not sure about the
others). You'll need to experiment with settings. Another possibility
could be interference from the scanner glass. If there's something on
it--cleaner, outgassing, or even just an aging coating, maybe the book
is pressing down on it and making an oil slick sort of effect. That's
just a wild guess. If it's less a "rainbow" or a pattern and more a
mottled appearance at full zoom, it might just be scanner noise. It's
hard to tell from your description.
If your main problem is a color shift in a particular direction, look
for color management settings in your scanner software. In one of my
first tests of color print scanning, I was bothered by a particular
shift from orange-red toward magenta. Switching the output color space
from the compressed sRGB to the wider AdobeRGB brought the colors much
closer to the original. You could also try using a standard color
chart to profile your scanner. If the color shift is consistent, a
single good profile will snap it back into place for multiple scans.
Full color management can be tricky (I only know some of the basics),
so if you don't already use it, you'll need to do some reading.
(There's also the possibility that your monitor isn't showing you what
the scanner sees. If it's not profiled and calibrated, try running
Adobe Gamma and seeing if things improve. Hardware-based calibration
is better, but AG should give you an idea if the monitor is a problem.)
Some inks and dyes will always show up differently under the scanner's
light than under ordinary (uncalibrated) room lighting; you'd have to
correct those in an image editor.
At this point, I haven't ruled out buying a new, newer scanner. But
I'd like to know these problems aren't still inherent in the latest
models.
The problems shouldn't be inherent in older models either. They might
be present, but if the hardware isn't malfunctioning, some of the above
suggestions should help.
I'm very much not an expert about all this, so no guarantees that my
answers are relevant. But I gave it my best shot. Hope it helps.
If I'm way off about anything, I'm sure someone will correct me.
false_dmitrii
