Scanning%20

1
Scanning conversion
Bulk work on ordinary printing Special efforts on
manuscripts Conversion of art works Non-visual
material
2
Modern printing
Sheet-fed vs. flatbed vs. look-down vs. digital
cameras A. Sheet-fed is fast, but requires
unbinding the book. B. Flatbed is slow, may
break binding, but the scanner is really
cheap. C. Look-down scanners rare Minolta
PS3000. Expensive, good quality, so far no
color. D. Digital cameras on copystands cheap,
good quality, some assembly required Too much of
the money goes to quality control.
3
Cost of scanning
You can get about 200-300 hand-driven exposures
per hour on a Minolta PS3000. Sheet fed systems
can do 5-6 books an hour if they dont
jam. Microfilm scanners can do 2 pages/second
(and the pages cant get out of order. Typical
numbers are 10 cents/page up to 25 cents/page.
4
Can you do OCR?
London paper, 1728. Rotten letters.
5
Comparison of resolutions
600, 150, and 100 dpi. (Original in small print).
6
Value of grey scale
Grey scale adds legibility (antialiases). Recently
reannounced with great commercial hype.
7

8
OCR again
Humphrey accused._at_of making more feathers fly
BARELY a fortnight after being cleared by
John Major of kflling four robin chicks
that were nesting in a windowbox outside the
Cabinet room, Humphrey the ...
9
Resolution
Michael Esters work 1000x1000 good enough
10
Special Materials
Electronic Beowulf (www.uky.edu/kiernan)
11
Undoing erasures
Importance of color imaging on black ink
12
Special illumination
Here backlight also low-incidence, UV, IR.
13
Conclusions
Text scanning is now a commodity. So is slide
scanning for art. Sound conversion is easy but
not standard, nor is video. The entertainment
industry is driving the technology libraries tag
along. What you have to choose is the balance
between cost and result. Perfection is
impossible and near-perfection can be too costly
a sloppy job might not get used at all. But
remember Voltaire The best is the enemy of the
good.