Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Raspberry PI camera?

Everything camera related. Includes triggers, batteries, power supplies, flatbeds and sheet-feeding scanners, too.
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BillGill
Posts: 98
Joined: 18 Dec 2016, 17:13
E-book readers owned: Calibre, FBReader
Number of books owned: 7000
Country: USA

Raspberry PI camera?

Post by BillGill » 26 Sep 2018, 09:54

It has occurred to me that a good camera for scanning books might be a Raspberry Pi camera. I did a really quick check on line and found this one on Amazon. https://www.amazon.com/Raspberry-Pi-Cam ... B01ER2SKFS At $25 dollars plus a Raspberry Pi kit ($50 at the top of the link) you could have a relatively inexpensive 8 MP camera.

You might have to configure the software, but there is a strong community of Raspberry Pi fans who have probably developed software that could be used to control the camera and download the pictures to your main computer.

Now that I have thought about this I may wind up having to actually do something with it. Of course I have been thinking of another project, so maybe not. We shall see.

Bill

duerig
Posts: 368
Joined: 01 Jun 2014, 17:04
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Country: United States of America

Re: Raspberry PI camera?

Post by duerig » 05 Oct 2018, 12:04

I have played around with this. There are a few limitation of Raspberry Pi cameras. The 8 MP resoloution, the complete lack of zoom, and the fact that a single Raspberry Pi can only handle one camera at a time. But they are cheap. They have manually-set focus control. And they are relatively more reliable than the CHDK-based solutions since they are designed up front to work with a computer controller rather than having that added in later by a third-party.

There are two possible ways to control dual cameras with the Raspberry Pi. First, there is a custom board somebody created that acts as a camera multi-plexer and is controlled with GPIO pins.

The second is that you can actually use three Raspberry Pi boards. Two Raspberry Pi Zeros and a Raspberry Pi 3 'hub' board. Each Raspberry Pi zero controls one camera and then talks using Ethernet-over-USB to the hub. The hub then consolidates the images and/or provides a UI. I got a proof-of-concept working for this at one point. But it would be neat to see it taken further.

-Jonathon Duerig

BillGill
Posts: 98
Joined: 18 Dec 2016, 17:13
E-book readers owned: Calibre, FBReader
Number of books owned: 7000
Country: USA

Re: Raspberry PI camera?

Post by BillGill » 06 Oct 2018, 09:40

I just got a Raspberry PI camera and am starting to play around with it. The lack of zoom doesn't bother me, since I am currently using a single camera system with the camera placed so that it just covers the platen with no zoom. I am hoping the 8 MP resolution will provide a better input to the OCR, so that the output will be closer to the original, without needing so much editing.

One of the things I have noticed about it is that there are a lot of cables coming out of it. Power, monitor, mouse, and keyboard. Some of those can be removed by using a wireless mouse and keyboard. Connecting it to another computer would add one more cable. So there may be some cable control issues.

Also I will need to work with the software to figure out the best control strategy. I may be able to download some good stuff from the Raspberry PI community. I may have to learn Python if I have to do any programming for myself. That may be frustrating, but I have done quite a bit of programming, so it shouldn't be too much trouble. Just the usual frustration of learning a new language.

Bill

BillGill
Posts: 98
Joined: 18 Dec 2016, 17:13
E-book readers owned: Calibre, FBReader
Number of books owned: 7000
Country: USA

Re: Raspberry PI camera?

Post by BillGill » 07 Oct 2018, 09:48

I got started working with the Raspberry Pi camera yesterday. I think maybe AMT's USB camera https://forum.diybookscanner.org/viewt ... =15&t=3535 might be a better choice than a Pi camera. If, as he says there is free software to control the camera, then you get to bypass a bunch of stuff in processing the pictures.

I have been able to get pictures using the Pi Cam, but I am still having problems getting the physical set up right. The thing about the PI Cam is that it has a manual focus. It comes with the focus set at infinity. If you want a closer focus you have to manually set it. In theory this is relatively simple. My camera came with a focus tool that slips over the lens and allows the focus to be easily adjusted. The problem I have encountered is that when I have the camera installed in a case I can't get the focus tool on the lens. Here is a photo of the camera installed in a standard style of case.
PiCamFocus.jpg
PiCamFocus.jpg (240.58 KiB) Viewed 209 times
Notice that the lens (that's that little black thing with a dot in the middle peeping through the holei n the case) is totally enclosed, with no way to reach it with the adjustment tool. That's the white plastic circle at the bottom of the picture. I thought at first I could enlarge the hole it is peeking through, but drilling one big enough for the tool would damage the camera mount, so that isn't an option.

One option would be to mount the camera separately, but that would leave the electronics exposed. I really don't like exposed electronics. I can probably come up with a solution, but it is obviously not a real simple job.

As far as I can see the USB camera is the same as the Pi Camera, with a different interface. So AMT will jut need to come up with a realistic mounting method.

Bill

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