On 10/26/05 2:26 PM, in article ,
"Geoffrey S. Mendelson" wrote:

In article ,
Antonio Vernucci wrote:

Very true. But why doing things worse when they can be easily done better.

The technology to produce high quality scans has been around
for almost 15 years. in early 1992, I produced for a client a CD ROM
with a hypertext database of article abstracts about their product and
it included 300 dpi scanned images of the articles.

To put it in context, I had to write a display and print program that
ran under DOS!!! because most people did not have Windows. In fact
we only made 500 of them because there were so few people with CD-ROM
drives. :-)

My CD-ROM drive cost me over $700, about half of a 386 computer without
one.

Now that everyone has a computer with a bitmaped display and many people
have scanners, you would think that there would be no problem getting
a good high resoultion scan of the manual.

However, most hams are computer users and not computer experts. They scan
images with whatever program that came with the scanner and use whatever
settings it defaults to. Unfortunately that's usually 200 DPI and 75%
quality JPEGS. Fine for scanning a copy of your photos for a web page,
or if you go directly to an inkjet printer or fax machine, but not
an archive copy of a drawing printed with a printing press.

File size grows geometricaly with the number of pixels you scan, a
letter size page at 300 dpi is 1,000,000 pixels. Lucklily the standard
for fax machines, uses a special compression method that works well for
black and white images and you can use it to compress a page of text
to about 50k. Line drawings tend not to be much more as it is designed
to work best with linear objects.

JPEG is not, it's designed to work with clumps of pixels that look alike,
and many colors. It is designed to make the copy look like the original
to the human eye, not be lossless compression.

So the bottom line is if you have any material in your library that
you would want the next generation to see, scan it in at at least 300dpi
and save it as "G3" encoded TIFF files.

If you have anything that you think people would want, but can't
do it yourself, ask around, there may be a local ham that could and
would do it for you.

Geoff.

I will add only one thing to the advice....

Many image problems are due to not having good brightness/contrast because
the scanner sees mostly white. Do a few sample scans while adjusting the
brightness and contrast for best result.

Don