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

Pi-Scan and Canon a2500 - trouble connecting

Discussions, questions, comments, ideas, and your projects having to do with DIY Book Scanner software. This includes the Stereo Data Maker software for the cameras, post-processing software, utilities, OCR packages, and so on.
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kayjay
Posts: 3
Joined: 16 Oct 2020, 22:13
E-book readers owned: 3 Kindles
Number of books owned: 2700
Country: United States

Pi-Scan and Canon a2500 - trouble connecting

Post by kayjay » 21 Oct 2020, 18:38

My question is about setting up the dual camera system using a Raspberry Pi 3 with a touch screen monitor and pi-scan.
I have the following DIY setup on my experimental A1 size bookscanner.
I have modified the structure of the scanner based on David Landin’s plan at
http://www.instructables.com/id/Book-Sc ... ages-an-h/
Hardware:
Raspberry Pi 3
Two - Canon A2500 cameras running pi-scan-camera-a2500-4317 on 32Gb Scandisk SDHC cards
2018-08-13-pi-scan-touch in the Raspberry Pi on a 32Gb Scandisk SDHC card.
My normal startup of the system is:
1. All components (Touchscreen, external 32 SDHC card via USB, both cameras) are hooked up to the Rasperry Pi.
2. I turn on the cameras and verify that CHDK loads on both. Then press the shutter release to extend the lens.
3. I turn on the raspberry and the monitor.
4. The Raspberry goes through lines and lines of script (every line has a green “OK”, except one that has a red “FAILED” “Failed to start create volatile files and directories see “systemctl status system-tempfiles-setup.service for details", pauses, then continues to load Pi Scan (?)
5. I get a screen that says Pi Scan 1.5 with a big button to begin scan.
6. The next screen confirms “Storage found, click next to continue”
7. The next screen searches for cameras. Comes back with “No cameras found . . .”
8. After a couple of minutes, both cameras lenses retract and the camera screen shows back with a “No Image) in the middle of it.
THIS IS WHERE I AM STUCK.
While the system is on: I have tried to disconnect the camera USB. I can get the lens to extend and an image on the screen, but when I plug the USB back in, the lens immediately retracts and the Black Screen “No Image” appears.
I have tried loading a2500-100a-1.4.1-5569-full_ALPHA on the cameras, but no change.
I have tried to load a2500-100a-1.4.1-5569_ALPHA on the cameras, no change.
I have taken screen shots, but I'm not sure if I'm allowed to upload them.

duerig
Posts: 385
Joined: 01 Jun 2014, 17:04
Number of books owned: 1000
Country: United States of America

Re: Pi-Scan and Canon a2500 - trouble connecting

Post by duerig » 23 Oct 2020, 16:06

Other than turning on the cameras, you should not be pressing the shutter or doing anything else to change their mode. The cameras should be on with the 'No Image' screen up until you take your first preview shot (the next stage after the cameras are detected).

So try turning off both cameras and the Pi, turning on everything but not otherwise changing the camera, and then see what happens. If you still get stuck on the 'No cameras found...' screen, then wait a bit, go back to the start 'Pi Scan 1.5' screen, and when it says you can safely eject the external storage take the external SD card out. That SD card should have a log and if you post it here or email me that might provide some insight into what is going wrong.

-Jonathon Duerig

kayjay
Posts: 3
Joined: 16 Oct 2020, 22:13
E-book readers owned: 3 Kindles
Number of books owned: 2700
Country: United States

Re: Pi-Scan and Canon a2500 - trouble connecting

Post by kayjay » 23 Oct 2020, 23:06

duerig wrote:
23 Oct 2020, 16:06
Other than turning on the cameras, you should not be pressing the shutter or doing anything else to change their mode. The cameras should be on with the 'No Image' screen up until you take your first preview shot (the next stage after the cameras are detected).

So try turning off both cameras and the Pi, turning on everything but not otherwise changing the camera, and then see what happens. If you still get stuck on the 'No cameras found...' screen, then wait a bit, go back to the start 'Pi Scan 1.5' screen, and when it says you can safely eject the external storage take the external SD card out. That SD card should have a log and if you post it here or email me that might provide some insight into what is going wrong.

-Jonathon Duerig
Thank you for your suggestion(s).
I continued to mess around with the setup, knowing it HAD to work :D (lol).
What I didn't mention in my equipment setup was that I had attached the Raspberry to a 7" Eviciv touch screen monitor. So I decided to go back to the basics and remove the Raspberry from the monitor and hook everything up as separate components. Since I wanted a footswitch to actuate the scanning process, I soon ran out of USB ports on the Raspberry, so I put a 4 port hub in one of the USB slots and hooked my cameras and the footswitch to the USB hub and the SDHC drive to the Raspberry USB ports.
:lol: VOILA! it works! I had the cameras turned on (lens in retracted position), as soon as the screen with zoom and other setup options appeared, the lenses popped out and I was on my way. Great programming!
Now my only problem is that although all the scans have good resolution, they have a severe blue cast to them (I'm using a 24w LED light source). I can get the blue out with photoshop, but it's kind of a pain in the neck.
My next adventure will be when I replace the current pi scan touch with a pi scan mouse (the person I built this for decided they wanted to use keyboard and mouse (NOW they tell me)
The a2500 cameras supply great left and right JPG files that have great resolution of the 22" x 17" pages from 6" thick volumes from back in 1923. The quality looks nearly the same as the original (after manipulation) but , as they say, "Garbage In - Garbage Out" so the images have all the flaws of the originals. I HATE it when they glue pictures onto double sided pages.
Kurt

kayjay
Posts: 3
Joined: 16 Oct 2020, 22:13
E-book readers owned: 3 Kindles
Number of books owned: 2700
Country: United States

Re: Pi-Scan and Canon a2500 - trouble connecting

Post by kayjay » 03 Nov 2020, 19:19

Now my only problem is that although all the scans have good resolution, they have a severe blue cast to them (I'm using a 24w LED light source). I can get the blue out with photoshop, but it's kind of a pain in the neck.
I have tried to adjust the f/stop in Pi-Scan, but they images continue to have the blue tinge.
Blue Tinge.jpg
I also notice that the capture file date capture on the SCHD card is always the same although the time changes by minutes.
Date is same.png
Date is same.png (39.75 KiB) Viewed 407 times

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LA2
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Re: Pi-Scan and Canon a2500 - trouble connecting

Post by LA2 » 07 Nov 2020, 11:50

This is called "white balance" and most cameras have a setting for it. Since incandescent lamps have a rather "warm" (yellow/red) light, the white balance setting to compensate for it reduces the red and increases the blue in the image. If you use this setting with true white light (daylight, LED lamps), the result will be a blueish picture. Check if you can change your camera's white balance setting from incandescent to daylight or something else.

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