Bookscanner
Kunlabora bookscanner building in progress right now! :) We are building this: https://forum.diybookscanner.org/viewtopic.php?f=1&t=333
Building a scanner
Here are two links to the public documentation of our scanner, built by Voja Antonic:
https://www.memoryoftheworld.org/blog/2012/10/28/our-beloved-bookscanner-2/
https://hackaday.io/project/5604-diy-book-scanner
We are trying to build something similar during the Kunlabora event in Calafou: https://calafou.org/en/content/kunlabora-ephimeral-projects-kooperative
We decided to build a more reproducible and portable and simple scanner: https://forum.diybookscanner.org/viewtopic.php?f=1&t=333
In theory for the simple scanner it should be possible to get all the ingredients from a hardware shop ("ferreteria"). We got most of the materials from Bauhaus in Barcelona (Zona Franca). TODO: list of materials, sources and prices.
Ideas for the building Voja's scanner
The electronics is not really documented (which means that it is hard to reproduce) and it is built from basic parts (which means that it takes a lot of time to put it together. So we try to use an Arduino-based solution instead. Arduino is a general-purpose programmable microcontroller that has already built-in many of the functions/parts we need. The idea is that this makes it easier for us to build the scanner and for others to reproduce it. We also have more experience working with Arduino than with only basic electronic components.
We will also try to use cheaper cameras in order to bring down the budget.
List of parts
From Bauhaus, Barcelona (Zona Franca):
- 2x Tablero MDF 600x400x10cm - 2x Tablero MDF 600x400x16cm - Varilla roscada - 2x Tira LED 1 nice - Multienchufa 5 tomas - Base 4 tomas 1.5 mts - Tuerca hexagonal - Guia corredera - 2x Arandela ancha - Aldabon BPF 185 M - Tornillo mad.cab.pl. - Tornillo cab. avell. - Tornillo p/metal - Tuerca palomilla - Guia cajones 10kg - Spax cab. red zinc - Tirador dorado
- 4x Abrazaderas - Colgador acero negro - Mosqueton-fw
Other things from other shops:
- 3x Cable USB 2.0 male-female @ Worten Sant Antoni - 2x USB-A -> USB-B (mini) cables @ Tienda de Cables - 2x Manfrotto brazo flexible MF237 (Nr. referencia AFP018036) @ FotoK, Ronda Universitat - 2 x digital cameras (see below for background information): Canon IXUS 175 (Powershot / ELPH 180) - https://www.amazon.es/Canon-IXUS-175-compacta-estabilizador/dp/B01A8QU70I/ - http://chdk.wikia.com/wiki/ELPH180 - https://www.canon-europe.com/for_home/product_finder/cameras/digital_camera/ixus/ixus_175/specification.aspx - 2 x gooseneck camera stand ("magic wand") - 2 x plexi glass from a company in Igualada that J. found.
For electronic parts a good shop in Barcelona is Diotronic: https://diotronic.com/
Cameras
Summary of research about cameras for book scanners:
Basically there are three categories of cameras that can be used for book scanners (from cheapest to most expensive).
1. Remote control support
The cheapest option is any camera with remote trigger support, so we can take pictures without pushing the button on the camera. This is important because when you press the button the camera position may be disadjusted to the physical pressure.
2. CHDK firmware
Middle category is CHDK firmware compatibles. CHDK is a third party open source firmware that allows the customisation of cameras. CHDK firmware is for Canon Powershot cameras, which are the cheaper compact digital camera product line. We have 200 euros in the budget for cameras, so we went with this option.
3. Magic Lantern support
Magic Lantern is a third party open source firmware that is more advanced. However, it only works with Canon DLSR cameras (these are the cameras that have a reflex mirror to look at the shot through a small hole before you take the picture, and they usually have big lenses). The scanner we have now uses Canon 1100D, which are the cheapest type suported by Magic Lantern, but they still cost a few hundred euros.
Pictures Day 1 (temporary)
- Error creating thumbnail: File missing
Scanning
The amount of work in the postproduction phase depends on how good quality images you can make in the scanning phase!
- Setting up the cameras (calibration): the most important part.
Caveats:
- open the book right in the middle (at the central page) to calibrate the cameras.
- camera should look at right angle on the page. Make sure the cameras are parallel to the angles of the cradle.
- all the page should be in the image
- check if the pages fold/curve; if so, place something underneath to straighten it (like a sponge, or another book...)
- camera settings: fully automatic, perhaps with manual focus.
- back up and empty the SD cards in the cameras
- most subtle mistake: one camera sees letters bigger than the other camera
- use a post-it or similar to mark the exact position of the book in relation to the lower edge of the cradle, to ensure it remains in the same position throughout the scanning.
- Push the big button on the scanner to scan.
- maybe you have to put your finger to the side of the plexiglass which is closer to you when it is “down”, because the plexiglass is not always exactly the same angle as the book pages
- Download the images from the SD cards and put the scanner to sleep.
- from the camera on the left, copy the images to a folder called “odd”
- from the camera on the right, copy the images to a folder called “even”
- upload the two folders now to to ftp://seldon.calafou/HackTheBiblio/scanning/<math>bookname--</math>yourname/ folder
- remember to delete the pictures from the SD cards and put them back to the cameras, and maybe put the camera batteries to charge
Dependencies
There are many ways to scan, this is the current state of the art in Calafou.
Using an up-to-date Debian operating system, you can install the following programs for the postproduction steps:
- scantailor
- gprename
- pdftk
- tesseract-ocr
- tesseract-ocr-eng
- tesseract-ocr-spa
- calibre
You can install all these programs with the following invocation:
sudo apt install scantailor gprename pdftk tesseract-ocr /
tesseract-ocr-eng tesseract-ocr-spa calibre
Postproduction
You start with two folders with files like IMG_1234.JPG
The basic workflow is like this:
- [program] ➔ [output]
- gprename ➔ 1.jpg, 2.jpg, …
- scantailor ➔ 1.tif, 2.tif, …
- tesseract ➔ 1.pdf, 2.pdf, …
- pdftk ➔ book.pdf
- calibre ➔ book.epub
- libgen.org ➔ http://libgen.org/book/index.php?md5=B6916395FDE00D91DB4F52DCB8F069BF
- etc.
There are some bash oneliners which can be useful (on Debian based systems):
FIXMEwe can probably write a script to rename the files properly… but for now, in gprename select the “numberical” tab, start = 1 for right-pages and 2 for left-pages, always step = 2.You can rotate the images appropriately (which is called “fix orientation” in scantailor) in the left/right folders before you import them. This is faster than in scantailor I think. However, you can also make the same operation in scantailor in a more user friendly way.
sudo apt-get install imagemagick cd left mogrify -verbose -rotate 270 * cd ../right mogrify -verbose -rotate 90 *
Does Optical Character Recognition (OCR) on all images in folder:
time for i in *tif; do b=$(basename $i .tif); tesseract -l spa "$i" "$b" pdf; done
Merges all the pdf files in folder into one single file:
pdftk *pdf cat output book.pdf
Exports the pdf metadata to a text file, to edit:
pdftk book.pdf dump_data output report.txt
Imports the metadata of report.txt back on the pdf:
pdftk book.pdf update_info report.txt output bookcopy.pdf
Distribution
Think about how people who would be interested in this book could know about it!
Repositories:
- General “educational materials”: Library Genesis
- Public library, radical books: Memory of the World
- Academic radical: Aaaaarg
- Artist radical: Monoskop
- Anarchist (including fanzines): Anarchist Library
- There are many Zine Libraries you can find on the Internet…
You may consider spreading the word on relevant mailing lists, social media, etc.
Raspberry Pi
It runs Raspbian.
CHDKPTP
In /home/pi/chdkptp there are precompiled binaries of CHDKPTP downloaded from here.
CHDKPTP is used for remote control of camera running CHDK firmware.
Our setup has two modes of work:
- mechanical "button" which triggers both camera capturing its photo
- (in progress) Raspberry Pi mode where an bookscanner operator uses Raspberry Pi to capture photos, preview photos in real time and transfer them already renamed for the next step in Scantailor.
When camera is connected this line will list info about the camera e.g.:
sudo ./chdkptp.sh -elist
and for one of the camera this is what is listed then:
-1:Canon IXUS 175 b=001 d=030 v=0x4a9 p=0x32c1 s=8B20D62641B041BAA3E1D597D560D110
An example of capturing a picture from commandline (once in /home/pi/chdkptp/):
sudo ./chdkptp.sh -e"connect -d=030" -erec -eshoot
Above line connects to the camera sitting on -d=021, puts it into rec mode (if not already) and capture the photo saving it to SD card already in camera. If one wants to bypass the SD card altogether it should replace -eshoot with -eremoteshoot. In that case ./chdkptp.sh will save photos into the directory from where it was called.
ZeroTier
It is added to 565799d8f6ebf1a8 public network of ZeroTier with this command:
sudo zerotier-cli join 565799d8f6ebf1a8
and it got static IP address (in 565799d8f6ebf1a8 network):
192.168.192.171/24
In /home/pi/.ssh/authorized_keys public keys of maxigas and marcell are added.
