Scanning Fiche

From: Zane H. Healy <>
Date: Sun Dec 6 19:15:18 1998

>Neither of these solutions exceeds 600 or 800 dpi, while with dedicated
>35mm scanners, that number is supposedly the high 1,000 to the middle
>2,000 per inch.

I believe the standard slide scanner resolution is about 2700dpi, while the
averave flatbed scanner still doesn't seem to be much above 600dpi, and the
ones with resolutions around 1200dpi are $2500-3000 while the slide
scanners are only $1000-2000.

Note, I'm talking optical resolution here, not interpolated. Interpolated
is basically some software trickery, which would be useless in something
like this.

>Are we talking jpegs/pdfs or ocr? How low a dpi can one go? Keeping in

I'd not really considered a file format, it wouldn't be JPEG though, as I
don't like the format.

>mind that everything aimed at consumers seems to reward routine scanning
>at excessive dpi, one could probably live with 200 dpi, if desperate,

A final output dpi of 150 to 200 would be fine, the problem is, a 8.5x11"
piece of paper is REALLY small when it's on MicroFiche, so you'd need to
scan it in at something like 2700dpi in order to get that. I just pulled a
sheet out and stuck it in my scanner, each page is about a quarter inch
square, and at 300dpi you can only read the section title pages. I'm not
even sure 2700dpi would cut it. At 300dpi individual lines are pixels, if
that good, I suspect it's actually several lines per pixel, but I don't
have the fiche reader set up.

A quick calculation shows that a quarter inch sqare scanned in at 2700dpi
would only equal about 61-79dpi That's readable on screen, but it probably
wouldn't be printable. Another reason not to use JPEG, when you've got
that little detail, you can't afford to loose any!

>perhaps less. Assuming that the fiche corresponds to a standard sheet of
>paper, then it is possible that a true scanner resolution of 600 or 800
>dpi will net 75 dpi for the finished product. Not so hot but might be

The sheet I was looking at has 208 pages on it, in a 13x16 grid, it's about
4x6" in size.

>I could suggest optically blowing it up via a photgraphic enlarger and
>then scanning the enlargement, but there is still the problem of cutting
>to fit and the whole process would be time consuming.

Ouch, that would be expensive, even doing my own developing, which I
actually have the equipment to do. I doubt it would be possible to project
the image directly onto the scanner. Hmmm....

>What about projecting it from the microfiche reader (either directly or
>using the screen) into something like a camcorder and then capturing as
>stills via a live feed?

To great of a loss of detail, even with a high quality view, fiche isn't
that easy to read.

>I assume there is a legitimate commercial way of scanning microfiche, but
>I suspect it requires a significant outlay of money.

I think so, I looked into what it would cost to get a reader with a built
in printer a couple months ago, turns out they cost about $5000.00, and
most places charge at least twenty-five cents a per page for copies.

| Zane H. Healy | UNIX Systems Adminstrator |
| (primary) | Linux Enthusiast |
| (alternate) | Classic Computer Collector |
| Empire of the Petal Throne and Traveller Role Playing, |
| and Zane's Computer Museum. |
| |
Received on Sun Dec 06 1998 - 19:15:18 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:30:47 BST