platen in Medak, Sekulic & Mertens 2014


arious manners depending on the scanning equipment, software, hacking
skills and user skill level that are available to your book scanning project. Several of those steps can
be handled by a single piece of equipment or software, or you might need to use a number of them your mileage will vary. Therefore, the manual will try to indicate the design choices you have in the
process of planning your workflow and should help you make decisions on what design is best for
you situation.
Introducing book scanner designs
The book scanning starts with the capturing of digital image files on the scanning equipment. There
are three principle types of book scanner designs:
 flatbed scanner
 single camera overhead scanner
 dual camera overhead scanner
Conventional flatbed scanners are widely available. However, given that they require the book to be
spread wide open and pressed down with the platen in order to break the resistance of the book
binding and expose sufficiently the inner margin of the text, it is the most destructive approach for
the book, imprecise and slow.
Therefore, book scanning projects across the globe have taken to custom designing improvised
setups or scanner rigs that are less destructive and better suited for fast turning and capturing of
pages. Designs abound. Most include:




one or two digital photo cameras of lesser or higher quality to capture the pages,
transparent V-shaped glass or Plexiglas platen to press the open book against a V-shape
cradle, and
a light source.

The go-to web resource to help you make an informed decision is the DIY book scanning
community at http://diybookscanner.org. A good place to start is their intro
(http://wiki.diybookscanner.org/ ) and scanner build list (http://wiki.diybookscanner.org/scannerbuild-list ).
The book scanners with a single camera are substantially cheaper, but come with an added difficulty
of de-warping the distorted page images due to the angle that pages are photographed at, which can
sometimes be difficult to correct in the post-processing. Hence, in this introductory chapter we'll
focus on two camera designs where the camera lens stands relatively parallel to the page. However,
with a bit of adaptation these instructions can be used to work with any other setup.
The Public Library scanner
In the focus of this manual is the scanner built for the Public Library project, designed by Voja
Antonić (see Illustration 1). The Public Library scanner was built with the immediate use by a wide
community of users in mind. Hence, the principle consideration in designing the Public Library
scanner was less sophistication and more robustness, facility of use and distributed process of
editing.
The board designs can be found here: http://www.memoryoftheworld.org/blog/2012/10/28/ourbeloved-bookscanner. The current iterations are using two Canon 1100 D cameras with the kit lens
Canon EF-S 18-55mm 1:3.5-5.6 IS. Cameras are auto-charging.

Illustration 1: Public Library Scanner
The scanner operates by automatically lowering the Plexiglas platen, illuminating the page and then
triggering camera shutters. The turning of pages and the adjustments of the V-shaped cradle holding

the book are manual.
The scanner is operated by a two-button controller (see Illustration 2). The upper, smaller button
breaks the capture process in two steps: the first click lowers the platen, increases the light level and
allows you to adjust the book or the cradle, the second click triggers the cameras and lifts the platen.
The lower button has
two modes. A quick
click will execute the
whole capture process in
one go. But if you hold
it pressed longer, it will
lower the platen,
allowing you to adjust
the book and the cradle,
and lift it without
triggering cameras when
you press again.

Illustration 2: A two-button controller

More on this manual: steps in the book scanning process
The book scanning process in general can be broken down in six steps, each of which will be dealt
in a separate chapter in this manual:
I. Photographing a printed book
I. Getting the image files ready for post-processing
III. Transformation of source images into .tiffs
IV. Optical character recognition
V. Creating a finalized e-book file
VI. Cataloging and sharing the e-book
A step by step manual for Public Library scanner
This manual is primarily meant to provide a detailed description and step-by-step instructions for an
actual book scanning setup -- based on the Voja Antonić's scanner design described above. This is a
two-camera overhead scanner, currently equipped with two Canon


f58c0b880c;hb=HEAD

I. PHOTOGRAPHING A PRINTED BOOK
Technologically the most demanding part of the scanning process is creating digital images of the
pages of a printed book. It's a process that is very different form scanner design to scanner design,
from camera to camera. Therefore, here we will focus strictly on the process with the Public Library
scanner.
Operating the Public Library scanner
0. Before you start:
Better and more consistent photographs lead to a more optimized and faster post-processing and a
higher quality of the resulting digital e-book. In order to guarantee the quality of images, before you
start it is necessary to set up the cameras properly and prepare the printed book for scanning.
a) Loosening the book
Depending on the type and quality of binding, some books tend to be too resistant to opening fully
to reveal the inner margin under the pressure of the scanner platen. It is thus necessary to “break in”
the book before starting in order to loosen the binding. The best way is to open it as wide as
possible in multiple places in the book. This can be done against the table edge if the book is more
rigid than usual. (Warning – “breaking in” might create irreversible creasing of the spine or lead to
some pages breaking loose.)
b) Switch on the scanner
You start the scanner by pressing the main switch or plugging the power cable into the the scanner.
This will also turn on the overhead LED lights.

c) Setting up the cameras
Place the cameras onto tripods. You need to move the lever on the tripod's head to allow the tripod
plate screwed to the bottom of the camera to slide into its place. Secure the lock by turning the lever
all the way back.
If the automatic chargers for the camera are provided, open the battery lid on the bottom of the
camera and plug the automatic charger. Close the lid.
Switch on the cameras using the lever on the top right side of the camera's body and place it into the
aperture priority (Av) mode on the mode dial above the lever (see Illustration 3). Use the main dial
just above the shutter button on the front side of the camera to set the aperture value to F8.0.

Illustration 3: Mode and main dial, focus mode switch, zoom
and focus ring
On the lens, turn the focus mode switch to manual (MF), turn the large zoom ring to set the value
exactly midway between 24 and 35 mm (see Illustration 3). Try to set both cameras the same.
To focus each camera, open a book on the cradle, lower the platen by holding the big button on the
controller, and turn on the live view on camera LCD by pressing the live view switch (see
Illustration 4). Now press the magnification button twice and use the focus ring on the front of the
lens to get a clear image view.

Illustration 4: Live view switch and magnification button

d) Connecting the cameras
Now connect the cameras to the remote shutter trigger cables that can be found lying on each side
of the scanner. They need to be plugged into a small round port hidden behind a protective rubber
cover on the left side of the cameras.
e) Placing the book into the cradle and double-checking the cameras
Open the book in the middle and place it on the cradle. Hold pressed the large button on the
controller to lower the Plexiglas platen without triggering the cameras. Move the cradle so that the
the platen fits into with the middle of the book.
Turn on the live view on the cameras' LED to see if the the pages fit into the image and if the
cameras are positioned parallel to the page.
f) Double-check storage cards and batteries
It is important that both storage cards on cameras are empty before starting the scanning in order
not to mess up the page sequence when merging photos from the left and the right camera in the
post-processing. To double-check, press play button on cameras and erase if there are some photos
left from the previous scan -- this you do by pressing the menu button, selecting the fifth menu from
the left and then select 'Erase Images' -> 'All images on card' -> 'OK'.
If no automatic chargers are provided, double-check on the information screen that batteries are
charged. They should be fully charged before starting with the scanning of a new book.

g) Turn off the light in the room
Lighting conditions during scanning should be as constant as possible, to reduce glare and achieve
maximum quality remove any source of light that might reflect off the Plexiglas platen. Preferably
turn off the light in the room or isolate the scanner with the black cloth provided.

1. Photographing a book
Now you are ready to start scanning. Place the book closed in the cradle and lower the platen by
holding the large button on the controller pressed (see Illustration 2). Adjust the position of the
cradle and lift the platen by pressing the large button again.
To scan you can now either use the small button on the controller to lower the platen, adjust and
then press it again to trigger the cameras and lift the platen. Or, you can just make a short press on
the large button to do it in one go.
ATTENTION: When the cameras are triggered, the shutter sound has to be heard coming
from both cameras. If one camera is not working, it's best to reconnect both cameras (see
Section 0), make sure the batteries are charged or adapters are connected, erase all images
and restart.
A mistake made in the photographing requires a lot of work in the post-processing, so it's
much quicker to repeat the photographing process.
If you make a mistake while flipping pages, or any other mistake, go back and scan from the page
you missed or incorrectly scanned. Note down the page where the error occurred and in the postprocessing the redundant images will be removed.
ADVICE: The scanner has a digital counter. By turning the dial forward and backward, you
can set it to tell you what page you should be scanning next. This should help you avoid
missing a page due to a distraction.
While scanning, move the cradle a bit to the left from time to time, making sure that the tip of Vshaped platen is aligned with the center of the book and the inner margin is exposed enough.

II. GETTING THE IMAGE FILES READY FOR POST-PROCESSING
Once the book pages have been photographed, they have to be transfered to the computer and
prepared for post-processing. With two-camera scanners, the capturing process will result in two
separate sets of images -- odd and even pages -- coming from the left and right cameras respectively
-- and you will need to rename and reorder them accordingly, rotate them into a vertical position
and collate them into a single sequence of files.
a) Transferring image files
For the transfer of files your principle process design choices are either to copy the files by
removing the memory cards from the cameras and copying them to the computer via a card reader
or to transfer them via a USB cable. The latter process can be automated by remote operating your
cameras from


gers into the battery slot and close the battery lid
- switch on the cameras
- switch the lens to Manual Focus mode
- switch the cameras to Av mode and set the aperture to 8.0
- turn the zoom ring to set the focal length exactly midway between 24mm and 35mm
- focus by turning on the live view, pressing magnification button twice and adjusting the
focus to get a clear view of the text
- connect the cameras to the scanner by plugging the remote trigger cable to a port behind a
protective rubber cover on the left side of the cameras
- place the book into the crade
- double-check storage cards and batteries
- press the play button on the back of the camera to double-check if there are images on the
camera - if there are, delete all the images from the camera menu
- if using batteries, double-check that batteries are fully charged
- switch off the light in the room that could reflect off the platen and cover the scanner with the
black cloth
1. Photographing
- now you can start scanning either by pressing the smaller button on the controller once to
lower the platen and adjust the book, and then press again to increase the light intensity, trigger the
cameras and lift the platen; or by pressing the large button completing the entire sequence in one
go;
- ATTENTION: Shutter sound should be coming from both cameras - if one camera is not
working, it's best to reconnect both cameras, make sure the batteries are charged or adapters
are connected, erase all images and restart.
- ADVICE: The scanner has a digital counter. By turning the dial forward and backward,
you can set it to tell you what page you should be scanning next. This should help you to
avoid missing a page due to a distraction.

II. Getting the image files ready for post-processing
- after finishing with scanning a book, transfer the files to the post-processing computer
and purge the memory cards
- if transferring the files manually:
- create two separate folders,
- transfer the files from the folders with image files on cards, using a batch
renaming software rename the files from the right camera fo

 

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