Hello
Here in my institution we are about to finish a project which comprehended
scanning blueprints which usually are very large formats (talking about A0+).
There are some possibilities in order to scan these records. But one must be
aware that the main problem is to get all the information in one shot, or two at
most, so as it won't be necessary to connect the images through post processing.
This because it turns all the process in a extremelly time consuming one. As you
we are talking about fragile documents drum scanning is not advisable.
You didn't say if colour is important for your project, but I assume it
is.
You have several options:
1. You get a vertical scanner that copes A0 formats together with a special
table that compresses the document so that it is perfectly flat on the capture
time (minolta ,Zeutschel...are some possible vendors..). The lightning problem
is solved as the table and scanner includes the necessary lamps to have the
images scanned.
2. You get a high resolution digital camera but only with a special macro
lens so as it may get close enough to get good level of detail and at the same
time allow just one or two captures. You have a issue here which is how are you
going to put the document in order to be photographed. You may put it over a
vertical surface (easier) or over a special horizontal device which is a better
solution for the document but harder under the capture point of view
3. You photograph the documents with an analogic camera on the 9/12 cm
size. You will get a negative big enough to comprehend the all document on one
shot. Then you have the negatives scanned. That's a very good solution but
requires a professional photograpoh as the 9/12 cameras are very expensive and
difficult to handle
4. If colour is not important, you may always microfilm the documents and
then have them scanned. That is not a good solution as you won't be able to get
the all image with 35 mm microfilm, and so a lot of post processing will still
be necessary. Besides the microfilm only gets back and white which usually is
not enough to accuratly capture complex documents such as maps or
blueprints.
IN any case a lot of benchmarking prior to the scanning process will be
necessary. And also a lot of planning regarding storage system of optical disks,
master acquisition and storage, regular backups, et, etc, etc,
hope this helps.
francisco barbedo
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