Scanning Resolution

[Grace Agnew]

Yvonne,

Best practice is to scan at an acceptably high resolution and store the
high-resolution scan for the future.  Why?

My thoughts:

(1)  TIFF images are the accepted "best practices" "standard"  (and I use
standards in quotes because TIFF is not an internationally adopted standard
with an organization providing ownership and control like JFIF (JPEG).
Scanning to a best practices standard means that your images join a large
body of work that must be supported over time.  Vendors are more likely to
provide migration paths for "best practices" image standards, other
institutions following best practices are will document their experiences
with storage, display and migration.

(2)  While the current Internet (and some computers) are not optimized for
the transport and display of high-resolution images, this will change
rapidly with high-speed networks, such as Abilene, etc.  As for the
computers themselves,  I am always amused that I buy a computer or
computers almost monthly and it seems the CPU speed, at least, has gone up
50 MHz each time.  The "base level" RAM and video cards increase each time,
as well.  Within a few years 600 dpi TIFF (an accepted "best practices"
standard) may seem grainy and of poor quality, based on newer CPUS,
monitors, graphics accelerators, etc.

(3)  Each scan does a little bit of damage--from handling, from the light
source, etc. to the image.  The initial scan is also time-consuming.  The
goal, of course, is to scan once only.  You want to scan at a "best
practices" resolution--the highest you can manage--once and then batch
process lower-resolution "use" images, using software like Thumbs Plus or
DeBabelizer.  You can strike as many lower-res use copies that you want
from a high-res image, but obviously not the other way around.

Hope this helps!

Grace Agnew
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Grace Agnew
Assistant Director for Systems & Technical Services
Georgia Tech Library
(404) 894-8932
(404) 894-6084 (fax)

mailto:grace.agnew at library.gatech.edu