Many databooks I find are printed on the fragile "telephone book" type
paper, either transparent, beige or both. Do you have any techniques
for getting good images out of those, and making sure they survive the
trip through the ADF?
Always scan those monochrome. (A lot of people insist on color
scanning of black and white materials)
On Fri, 14 Jul 2017, Paul Koning wrote:
You mean grayscale, right -- not bitonal. I sometimes scan on
copier/scanner units because they happen to be available, but they are
often bitonal and produce images with lots of black noise pixels. With
grayscale scans, you can avoid those by tweaking the threshold and/or
adjusting the curves.
Yes.
Although SOME scanners have good threshold levels for bitonal.
What I object to is people who insist on 24 bit color with lossless
compression. We are after the information content here, not a study of
paper texture and analysis of aging/deterioration.
Sometimes a lossy compression will try to delete some of the noise,
whereas a lossless compression will retain it.
"Doctor Marty" (formerly Coco) runs a large project digitizing some
periodicals from the 1920s and 1930s.
