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Input on the best way to build a portable scanner

Posted: 16 Nov 2010, 19:53
by o3h1p
Hello.
I am just starting to do research into making a book scanner but my major problem is that I don't have any room to bulid some of the amazing scanners that I see on here. The only portable model I found was:

http://www.instructables.com/id/New-Imp ... al-Copy-M/

I assume this model is just a "pick up" and "put down" model.

Questions:
1) If I hooked it up to a timer or a switch with the right camera and good lighting, how good do you think the results would be?
2) Does anyone know of any other portable projects people have done?
3) What is the drawback from this setup given that i don't have old books to scan.
4) Would there be any problems if the pages are not lined up in the exact same position as the others? I assume the software would correct for that?
5) Any camera recommendations? I'm assuming I should get something compatible with CHDK.
6) I am comfortable with both windows and linux. I assume that it should be easy to just throw all the images into a directory and a script can be easily designed that will rotate,crop,cut, and assemble with a single command. Has this been done? Maybe the final OCR can be done with AbbyReader or something I guess.

Sorry for my basic questions and really any input you can provide to this beginner will be greatly appreciated.

Jack

Re: Input on the best way to build a portable scanner

Posted: 16 Nov 2010, 20:20
by Moonboy242
There's this example of a portable bookscanner:

http://bkrpr.org/doku.php

The primary challenge I can think of (I'm sure others will have more insight) is obtaining accurate and consistent scans. Most errors associated with scanning can be corrected using ScanTailor and Gimp, the real variable is the amount of time you want to spend correcting each and every page in a book scan. You really want to get as close as you can get to perfect scans with your camera for each and every page.

I think the next big consideration (particularly with the "paperless digital copy" thingy) is stablity. You would have to set the book down, place the scanner on top of the book, hold the other pages down so the book doesn't close and move the scanner, and then take the picture (or use an intervalometer script). The Bkrpr seems to sorta address the issues, but you're still going to have to lift the scanner, turn a page, and then set the scanner back down in the same general area as the previous page... then take your pics. Of the two, Bkrpr seems to be the better deal.

Your cameras? This thread should help address your questions:

http://www.diybookscanner.org/forum/vie ... ?f=1&t=332

Re: Input on the best way to build a portable scanner

Posted: 16 Nov 2010, 20:27
by spamsickle
o3h1p wrote: Questions:
1) If I hooked it up to a timer or a switch with the right camera and good lighting, how good do you think the results would be?
If you have a camera with CHDK, my choice would be a short one-shot timer script that waited a second after you pressed the button to fire the shutter. This would get good throughput with the "pick it up and put it down" hardware, and should eliminate any vibration that might be caused by pushing the button.

If you don't have CHDK, I'd just go with pushing the button, though if you can get a remote release for your camera, I'd do so.

As for the results, it probably depends mostly on the lighting. You shouldn't depend on the camera's flash in this configuration, because if the material you're scanning is glossy, you'll get glare that will wash out content. Overhead lights may cause the camera itself to cast a shadow on the content. I'd take the shadow over the glare, but if you have some ideas for auxiliary lighting, that could make a big difference in the quality you can get.
o3h1p wrote:2) Does anyone know of any other portable projects people have done?
I don't. I've had some ideas for portable hardware, but I haven't gone into the field with anything yet.
o3h1p wrote:3) What is the drawback from this setup given that i don't have old books to scan.
The biggest drawback, other than the lighting, is that it's difficult to get consistency from one page to the next with a camera that's attached to moving parts. You might be able to improve this design with some kind of frame around the book, that will guide its placement from shot to shot.

One other drawback I can envision is that the size of the books you can scan may be limited to a certain range. A book may be too small for the stand to hold open, or so large that the stand blocks content.
o3h1p wrote:4) Would there be any problems if the pages are not lined up in the exact same position as the others? I assume the software would correct for that?
This is more of a problem with the "single command" kind of post-processing you propose than with something like Scan Tailor (which is what most people here use at some point) which handles most alignment problems transparently.
o3h1p wrote:5) Any camera recommendations? I'm assuming I should get something compatible with CHDK.
See the "camera recommendation" thread. I'm using CHDK-enabled 8 MP cameras, and they seem just fine to me.
o3h1p wrote:6) I am comfortable with both windows and linux. I assume that it should be easy to just throw all the images into a directory and a script can be easily designed that will rotate,crop,cut, and assemble with a single command. Has this been done? Maybe the final OCR can be done with AbbyReader or something I guess.
It has been done, but as I say, most people are using Scan Tailor because it does so many good things. Check out Misty's PDF builder too, or roll your own.

In general, most of us aren't doing single-command post processing at this point, but that may be more common in the future. Maybe you'll help to bring it to fruition.

Re: Input on the best way to build a portable scanner

Posted: 16 Nov 2010, 20:30
by o3h1p
Thank you for your quick reply moonboy. I just ran into this one by Antoha-spb:

http://www.diybookscanner.org/forum/vie ... ?f=1&t=175

I saw the liberator but the problems I hve with it is that it doesn't look all that portable (probably more so than most) and the 2 camera setup increases the cost. If I etch a line in Antoha's setup I could probably put the book consistently in the same spot.

Thank you very much for the links and the quick reply!

Re: Input on the best way to build a portable scanner

Posted: 16 Nov 2010, 20:48
by o3h1p
Thanks for the reply spamsickle. I didn't know about scan taylor, it looks like a neat project. That seems to take care of almost everything you would want.

Re: Input on the best way to build a portable scanner

Posted: 16 Nov 2010, 21:36
by daniel_reetz
Great answers here from some great people. I also have a "master list of all scanner builds" that I sometimes maintain. It's about two months behind right now:

http://delicious.com/danreetz/DIYBookScanner

and

http://www.diybookscanner.org/forum/vie ... ?f=1&t=280

It's good to look through that list to get some ideas... there are a few portable scanners in there, some using only one scanner..

Re: Input on the best way to build a portable scanner

Posted: 17 Nov 2010, 19:55
by nalfonso
You may want to check this for the hardware part:

http://www.diybookscanner.org/forum/vie ... ?f=1&t=103

Check Dan's link for my PDF in that page, because the link to drop.io is no longer good, for drop.io is closing!

Regards,

nalfonso

Re: Input on the best way to build a portable scanner

Posted: 17 Nov 2010, 19:58
by daniel_reetz
NALFONSO!!

Did you ever get a chance to look at the lighting component of your scanner!!??

Re: Input on the best way to build a portable scanner

Posted: 17 Nov 2010, 20:51
by o3h1p
Yes I saw yours nalfonso but it doesn't show the lighting or camera mounts.
jack

Re: Input on the best way to build a portable scanner

Posted: 18 Nov 2010, 12:24
by Misty
Nalfonso, good to see you around again! Haven't seen you here in ages.