Post by Art Todesco
I have an Epson V37 scanner and a laser printer. Epson has a utility to
make copies. Folks here helped me some time back roll back to an
earlier version of the copy routine which, in my opinion, worked far
better than the current one. But, one problem still prevails. It takes
forever to make a copy. It 1st scans (fast rough scan) the original to
size it up and then, eventually, scans at a slower rate to make the copy
and the computer (Epson Scan) sends it to the laser for printing. Does
anyone know of a utility that just plain scans 8.5 x 11 and prints it
fast? I've looked around and haven't found anything that looks promising.
Make sure the resolution is not set too high.
4800 DPI is too high for making paper copies of something.
Most printed materials you get in the mail, will consist
of halftone "dots", and scanning at higher than twice the
dot pitch is not supposed to improve the quality of the output.
(That's an application of the Nyquist sampling theorem.)
If you're handling photographic prints, the grain is
a lot smaller on stuff like that, and doesn't have nearly
the uniform pattern of halftone prints from magazines
or the like. You can crank the daylights out of the
resolution on those (your choice).
Maybe scanning at 150 DPI to 300 DPI is sufficient, depending on
the source material. For newsprint, the correct value is
My scanner has a plugin that (partially) removes moire.
Moire caused by aliasing between the dot pitch and the
scanning resolution. And that's why I tend to "count the
dots per inch", before doing scans. So I don't select
too high a resolution, wasting storage space and speed.
I tell the plugin what dot frequency is involved, for
best results, and it takes care of the details.
My scanner never delivers data faster than 1MB/sec to 2MB/sec
or so. I expect yours is a lot better than mine. The speed
is limited by available light - the stepper has to stop moving
the carriage, the CCD or CMOS linear array "snaps a picture" and
the transport moves to the next row. The scanner tries to use
a bright light source, to reduce the exposure time after
the stepper stops to snap a row. But too much light, too aggressive
an approach, can damage sensitive (ancient) source materials.
That may be why they don't try a few million candle power
under the hood :-)
You can take snapshots of a printed page with a digital
camera, which results in a "scan" in a fraction of a second.
A 12 megapixel camera would be a good starting material.
The lens used is probably a limiting factor (barrel distortion,
chromatic aberration, all that photography jazz).