duerig
Posts: 4
Joined: Mon Jan 11, 2016 8:46 pm

Book Scanner Controller with a Raspberry Pi

Fri Jan 29, 2016 10:05 pm

I am using a Raspberry Pi 2 and Pi Display is to control a book scanner as a standalone appliance:

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The Raspberry Pi controls and configures both cameras, remotely captures the images, and saves them to an external SD card.

You pull down on the handlebar to press pages flat against the glass. Lighting comes from above.

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The open source project for the software is called Pi Scan:

http://github.com/Tenrec-Builders/pi-scan

-D

gkreidl
Posts: 6345
Joined: Thu Jan 26, 2012 1:07 pm
Location: Germany

Re: Book Scanner Controller with a Raspberry Pi

Fri Jan 29, 2016 11:02 pm

Which kind of cameras do you use?
Minimal Kiosk Browser (kweb)
Slim, fast webkit browser with support for audio+video+playlists+youtube+pdf+download
Optional fullscreen kiosk mode and command interface for embedded applications
Includes omxplayerGUI, an X front end for omxplayer

duerig
Posts: 4
Joined: Mon Jan 11, 2016 8:46 pm

Re: Book Scanner Controller with a Raspberry Pi

Fri Jan 29, 2016 11:08 pm

I'm using Canon PowerShot ELPH 160 cameras now, and also recommend Canon PowerShot A2500 cameras. I have CHDK images for both cameras linked in the project. Any CHDK-compatible camera may work with Pi Scan, but those are the two kinds of cameras I have on hand.

The ELPH 160 cameras give about 300 DPI scans, though it is possible to get a bit better than that by zooming in on small books.

Edit: ELPH 160 cameras are marketed as IXUS 160 cameras in Europe.

-D

Slackware
Posts: 131
Joined: Mon Jan 18, 2016 3:45 pm

Re: Book Scanner Controller with a Raspberry Pi

Thu Feb 11, 2016 11:33 pm

very nice. I was working on a spine wedge to press book out flat. I like the idea of the 'V' and shoot at an angle. Like you I figured a camera snapshot beats a scanner dragging across the page.
How is optical distortion and glare going through the glass?

duerig
Posts: 4
Joined: Mon Jan 11, 2016 8:46 pm

Re: Book Scanner Controller with a Raspberry Pi

Fri Feb 12, 2016 5:09 pm

Slackware, this is 3mm glass and I don't notice any distortion. You can see sample scans at:

http://tenrec.builders/quill/samples/sample-1.jpg
http://tenrec.builders/quill/samples/sample-2.jpg

These are raw images taken off of the cameras.

The angle of the platen (100 degrees) combined with the distance of the light minimizes glare. But you have to scan in the dark, otherwise ambient lights might cause artifacts. It also helps that each LED projects its lights through a pair of lenticular sheets. One horizontal and one vertical. This spreads out the light pretty evenly.

I designed my scanner so I could just put a standard Archivist lighting module on top. That meant that I could take advantage of the existing LED/lenticular sheet/baffle design by Daniel Reetz (see http://www.diybookscanner.org/archivist/?page_id=236 for some interesting pictures/gifs/videos about lighting).

There is still a little bit of glare that you might notice if the glass is dirty. A fellow going by the username ilsamors on the diybookscanner forum has experimented with specially coated anti-reflective glass to reduce any potential glare even more. That is a potentially interesting (if expensive) avenue to explore.

One big problem with using a glass platen is books with text very close to the gutter. There is a small blind spot where the glass meets. And if there isn't a good margin in the center, that blind spot could cut off text. The other problem is when scanning small normally-closed paperbacks. They have a tendency to snap shut every time you lower the cradle.

-D

Slackware
Posts: 131
Joined: Mon Jan 18, 2016 3:45 pm

Re: Book Scanner Controller with a Raspberry Pi

Fri Feb 12, 2016 9:33 pm

Yea I bought a piece of that glass back in 81 and it wasn't cheap then. You can get it from frame shops, they use it for mounting art prints.

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helen
Raspberry Pi Trading Employee & Forum Moderator
Raspberry Pi Trading Employee & Forum Moderator
Posts: 225
Joined: Fri Jul 20, 2012 3:41 pm
Location: Cambridge, UK

Re: Book Scanner Controller with a Raspberry Pi

Tue Feb 16, 2016 1:34 pm

duerig's scanner is the subject of today's post on the Raspberry Pi blog: http://www.raspberrypi.org/blog/raspber ... k-scanner/. Thanks for sharing it with us, duerig!

duerig
Posts: 4
Joined: Mon Jan 11, 2016 8:46 pm

Re: Book Scanner Controller with a Raspberry Pi

Tue Feb 16, 2016 3:25 pm

helenlynn, that is great to hear! Thanks for the write-up.

FYI, I created a few videos of using the scanner.

Preparing to scan: https://vimeo.com/154514341
Scanning: https://vimeo.com/154515311
Completing a scan: https://vimeo.com/154515969

-D

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scruss
Posts: 4855
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Location: Toronto, ON

Re: Book Scanner Controller with a Raspberry Pi

Tue Feb 16, 2016 7:42 pm

Nice project!

I've been working with software coming out of the DIY Book Scanner movement to archive bills and other paperwork. None of this fun hardware, though.
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