[00:13]
Public Library is the concept, the idea, to encourage people to become a
librarian, where a librarian is a person which can allow access to books – and
also which has a catalogue or index, so that it's searchable. [00:32] And the
person, the human being, can communicate, can talk with others who are
interested in that catalogue of books. [00:43] And then when you have a
librarian, and you have a lot of librarians, you have a Public Library,
because we have access to books, we have a catalogue, and we have a librarian.
That's the basic set up. [00:55] And in order to really work, in practice, we
need to introduce a set of tools which are easy to use, like Calibre, for
example, for book management. [01:07] And then also some part of that set up
should be also developed because at the moment, because of the configuration
of the routers, IP addresses and other things, it's not that easy to share
your local library which you have on your laptop with the world. [01:30] So we
also provide... When I say ‘we,’ it's a small team, at the moment, of
developers who try to address that problem. [01:38] We don't need to reinvent
the public library. It's invented, and it should be just maintained. [01:47]
The old-school public libraries – they are in decline because of many reasons.
And when it comes to the digital networks, the digital books, it's almost like
the worst position. [01:59] For example, public libraries in the US, they are
not allowed to buy digital books, for example from Penguin. So even when they
want to buy, it's not that they are getting them, it's that they can't buy the
books. [02:16] By the current legal regulation, it's considered as illegal – a
million of books, or even more, are unavailable, and I think that these books
should be really available. [02:29] And it doesn't really matter how it got on
Internet – did it come from a graphic designer who is preparing that for
print, or if it was uploaded somewhere from the author of the book (that is
also very common, especially in humanities), or if it was digitised anywhere.
[02:50] So these are the books which we have, and we can't be blinded, they
are here. The practice at the moment is almost like trying to find a
prostitute or something, so when you want to get a book online you need to get
onto the websites with advertisements for casinos, for porn and things like
that. [03:14] I don't think that the library should be like that.
[03:18]
Book Management
[03:22]
What we are trying to provide is just suggesting what kind of book management
software they can use, and also what kind of new software tools they can
install in order to easily get the messy directory into the directory of
metadata which Calibre can recognise – and then you can just use Calibre. The
next step is if you can share your local library with the world. [03:52] You
need something like a management software where it's easy to see who are the
authors, what the titles, publishers and all of the metadata – and it's
accessible from the outside.
[04:08]
Calibre
[04:12]
Calibre is a book management software. It's developed by Kovid Goyal, a
software developer. [04:22] It's a free software, open source, and it started
like many other free software projects. It started as a small tool to solve
very particular small problems. [04:31] But then, because it was useful, it
got more and more users, and then Kovid started to develop it more into a
proper, big book management software. At the moment it has more that 10
million registered users who are running that. [04:52] It does so many things
for book management. It's really ‘the’ software tool... If you have an
e-reader, for example, it recognises your e-reader, it registers it inside of
Calibre and then you can easily just transfer the books. [05:08] Also for
years there was a big problem of file formats. So for example, Amazon, in
order to keep their monopoly in that area, they wouldn't support EPUB or PDF.
And then if you got your book somewhere – if you bought it or just downloaded
from the Internet, you wouldn't be able to read it on your reader. [05:31]
Then Calibre was just developing the converter tools. And it was all in one
package, so that Calibre just became the tool for book management. [05:43] It
has a web server as a part of it. So in a local area network – if you just
start that web server and you are running a local area network, it can have a
read-only searchable access to your local library, to your books, and it can
search by any of these metadata.
[06:05]
Tools Around Calibre
[06:09]
I developed a software which I call Let's Share Books, which is super small
compared to Calibre. It just allows you, with one click, to get your library
shared on the Internet. [06:24] So that means that you get a public URL, which
says something like www some-number dot memoryoftheworld dot net, and that is
the temporary public URL. You can send it to anyone in the world. [06:37] And
while you are running your local web server and share books, it would just
serve these books to the Internet. [06:45] I also set up a web chat – kind of
a room where people can talk to each other, chat to each other. [06:54] So
it’s just, trying to develop tools around Calibre, which is mostly for one
person, for one librarian – to try to make some kind of ecosystem for a lot of
librarians where they can meet with their readers or among themselves, and
talk about the books which they love to read and share. [07:23] It’s mostly
like a social networking around the books, where we use the idea and tradition
of the public library. [07:37] In order to get there I needed to set up a
server which only does routing. So with my software I don’t know which books
are transferred, anything. It’s just like a router. [07:56] You can do that
also if you have control of your router, or what we usually call modem, so the
device which you use to get to the Internet. But that is quite hard to hack,
just hackers know how to do that. [08:13] So I just made a server on the
Internet which you can use with one click, and it just routes the traffic
between you, if you’re a librarian, and your users, readers. So that’s that
easy.
[08:33]
Librarians
[08:38] It’s super easy to become a librarian, and that is what we should
celebrate. It’s not that the only librarians which we have were the librarians
who were the only ones wanting to become a librarian. [08:54] So lots of
people want to be a librarian, and lots of people are librarians whenever they
have a chance. [09:00] So you would probably recommend me some books which you
like. I’ll recommend you some books which I like. So I think we should
celebrate that now it’s super easy that anyone can be a librarian. [09:11] And
of course, we will still need professional librarians in order to push forward
the whole field. But that goes, again, in collaboration with software
engineers, information architectes, whatever… [09:26] It’s so easy to have
that, and the benefits of that are so great, that there is no reason why not
to do that, I would say.
[09:38]
Functioning
[09:43]
If you want to share your collection then you need to install at the moment
Calibre, and Let’s Share Books software, which I wrote. But also you can – for
example, there is a Calibre plugin for Aaaaarg, so if you use Calibre… from
Calibre you can search Aaaaarg, you can download books from Aaaaarg, you can
also change the metadata and upload the metadata up to Aaaaarg.
[10:13]
Repositories
[10:17]
At the moment the biggest repository for the books, in order to download and
make your catalogue, is Library Genesis. It’s around 900,000 books. It’s
libgen.info, libgen.org. And it’s a great project. [10:33] It’s done by some
Russian hackers, who also allow anyone to download all of that. It’s 9
Terabytes of books, quite some chunk of hard disks which you need for that.
[10:47] And you can also download PHP, the back end of the website and the
MySQL database (a thumb of the MySQL database), so you can run your own
Library Genesis. That’s one of the ways how you can do that. [11:00] You can
also go and join Aaaaarg.org, where it is also not just about downloading
books and uploading books, it’s also about communication and interpretation of
making, different issues and catalogues. [11:14] It’s a community of book
lovers who like to share knowledge, and who add quite a lot of value around
the books by doing that. [11:26] And then there is… you can use Calibre and
Let’s Share Books. It’s just one of these complimentary tools. So it’s not
really that Calibre and Let’s Share Books is the only way how you can today
share books.
[11:45]
Goal
[11:50]
What we do also has a non-hidden agenda for fighting for the public library. I
would say that most of the people we know, even the authors, they all
participate in the huge, massive Public Library – which we don’t call Public
Library, but usually just trying to hide that we are using that because we are
afraid of the restrictive regime. [12:20] So I don’t see a reason why we
should shut down such a great idea and great implementation – a great resource
which we have all around the world. [12:30] So it’s just an attempt to map all
of these projects and to try to improve them. Because, in order to get it into
the right shape, we need to improve the metadata. [12:47] Open Library, a
project which started also with Aaron Swartz, has 20 millions items, and we
use it. There is a basedata.org which connects the hash files, the MD5 hashes,
with the Open Library ID. And we try to contribute to Open Library as much as
possible. [13:10] So with very few people, around 5 people, we can improve it
so much that it will be for a billion of users a great Public Library, and at
the same time we can have millions of librarians, which we never had before.
So that’s the idea. [13:35] The goal is just to keep the Public Library. If we
didn’t screw up the whole situation with the Public Library, probably we’d
just try to add a little bit of new software, and new ways that we can read
the books. [13:53] But at the moment [it’s] super important actually to keep
this infrastructure running, because this super important infrastructure for
the access to knowledge is now under huge threat.
[14:09]
Copyright
[14:13]
I just think that it’s completely inappropriate – that copyright law is
completely inappropriate for the Public Library. I don’t know about other
cases, but in terms of Public Library it’s absolutely inappropriate. [14:29]
We should find the new ways of how to reward the ones who are adding value to
sharing knowledge. First authors, then anyone who is involved in public
libraries, like librarians, software engineers – so everyone who is involved
in that ecosystem should be rewarded, because it’s a great thing, it’s a
benefit for the society. [15:03] If this kind of things happens, so if the law
which regulates this blocks and doesn’t let that field blossom, it’s something
wrong with that law. [15:16] It’s getting worse and worse, so I don’t know for
how long we should wait, because while we’re waiting it’s getting worse.
[15:24] I don’t care. And I think that I can say that because I’m an artist.
Because all of these laws are made saying that they are representing art, they
are representing the interest of artists. I’m an artist. They don’t really
represent my interests. [15:46] I think that it should be taken over by the
artists. And if there are some artists who disagree – great, let’s have a
discussion.
[15:58]
Civil Disobedience
[16:03]
In the possibilities of civil disobedience – which are done also by
institutions, not just by individuals – and I think that in such clear cases
like the Public Library it’s easy. [16:17] So I think that what I did in this
particular case is nothing really super smart – it’s just reducing this huge
issue to something which is comprehensible, which is understandable for most
of the people. [16:31] There is no one really who doesn’t understand what
public library is. And if you say to anyone in the world, saying, like hey, no
more public libraries, hey, no books anymore, no books for the poor people. We
are just giving up on something which we almost consensually accepted through
the whole world. [16:55] And I think that in such clear cases, I’m really
interested [in] what institutions could do, like Transmediale. I’m now in
[Akademie] Schloss Solitude, I also proposed to make a server with a Public
Library. If you invest enough it’s a million of books, it’s a great library.
[17:16] And of course they are scared. And I think that the system will never
really move if people are not brave. [17:26] I’m not really trying to
encourage people to do something where no one could really understand, you
know, and you need expertise or whatever. [17:37] In my opinion this is the
big case. And if Transmediale or any other art institution is playing with
that, and showing that – let’s see how far away we can support this kind of
things. [17:56] The other issue which I am really interested in is what is the
infrastructure, who is running the infrastructures, and what kind of
infrastructures are happen in between these supposedly avant-garde
institutions, or something. [08:12] So I’m really interested in raising these
issues.
[18:17]
Art Project
[18:21]
Public Library is also an art project where… I would say that just in the same
way that corporations, by their legal status, can really kind of mess around
with different… they can’t be that much accountable and responsible – I think
that this is the counterpart. [18:44] So civil disobedience can use art just
the same way that corporations can use their legal status. [18:51] When I was
invited as a curator and artist to curate the HAIP Festival in Ljubljana, I
was already quite into the topic of sharing access to knowledge. And then I
came up with this idea and everybody liked it and everybody was enthusiastic.
It's one of these ideas where you can see that it’s great, there is no one
really who would oppose to that. [19:28] At the same time there was an
exhibition, Dear Art, curated by WHW, quite established curators. And then it
immediately became an art piece for that exhibition. Then I was invited here
to Transmediale, and have a couple of other invitations. [19:45] I think that
it also shows that art institutions are accepting that, they play with that
idea. And I think that this kind of projects – by having that acceptance it
becomes the issue, it becomes the problem of the whole arts establishment.
[20:10] So I think that if I do this in this way, and if there is a curator
who invites this kind of projects – so who invites Public Library into their
exhibition – it’s also showing their kind of readiness to fight for that
issue. [20:27] And if there are a number of art festivals, a number of art
exhibitions, who are supporting this kind of, lets say, civil disobedience,
that also shows something. [20:38] And I think that that kind of context
should be pushed into the confrontation, so it’s not anymore just playing “oh,
is it is ok, it is not? We should deal with all the complexity…” [20:57] There
is no real complexity here. That complexity is somewhere else, and in some
other step we should take care of that. But this is an art piece, it’s a well
established art piece. [21:11] If you make a Public Library, I'm fine, I’m
sacrificing for taking the responsibility. But you shouldn't melt down that
art piece, I think. [21:26] And I feel super stupid that such a simple concept
should be, in 2013, articulated to whom? In many ways it’s like playing dummy,
I play dummy. It’s like, why should I? [21:50] When we started to play in
Ljubljana like software developers we came up with so many great ideas of how
to use those resources. So it was immediately… just after couple of hours we
had tools – visualisations of that, a reader of Wikipedia which can embed any
page which is referred, as a reference, a quote. [22:17] It was immediately
obvious for anyone there and for anyone from the outside what a huge resource
is having a Public Library like that – and what’s the huge harm that we don’t
have it. [22:32] But still we need to play dummy, I need to play the artist’s
role, you know.
Medak, Sekulic & Mertens
Book Scanning and Post-Processing Manual Based on Public Library Overhead Scanner v1.2
2014
PUBLIC LIBRARY
&
MULTIMEDIA INSTITUTE
BOOK SCANNING & POST-PROCESSING MANUAL
BASED ON PUBLIC LIBRARY OVERHEAD SCANNER
Written by:
Tomislav Medak
Dubravka Sekulić
With help of:
An Mertens
Introduction
3
I. Photographing a printed book
7
I. Getting the image files ready for post-processing
11
III. Transformation of source images into .tiffs
13
IV. Optical character recognition
16
V. Creating a finalized e-book file
16
VI. Cataloging and sharing the e-book
16
Quick workflow reference for scanning and post-processing
18
References
22
INTRODUCTION:
BOOK SCANNING - FROM PAPER BOOK TO E-BOOK
Initial considerations when deciding on a scanning setup
Book scanning tends to be a fragile and demanding process. Many factors can go wrong or produce
results of varying quality from book to book or page to page, requiring experience or technical skill
to resolve issues that occur. Cameras can fail to trigger, components to communicate, files can get
corrupted in the transfer, storage card doesn't get purged, focus fails to lock, lighting conditions
change. There are trade-offs between the automation that is prone to instability and the robustness
that is prone to become time consuming.
Your initial choice of book scanning setup will have to take these trade-offs into consideration. If
your scanning community is confined to your hacklab, you won't be risking much if technological
sophistication and integration fails to function smoothly. But if you're aiming at a broad community
of users, with varying levels of technological skill and patience, you want to create as much timesaving automation as possible on the condition of keeping maximum stability. Furthermore, if the
time of individual members of your scanning community can contribute is limited, you might also
want to divide some of the tasks between users and their different skill levels.
This manual breaks down the process of digitization into a general description of steps in the
workflow leading from the printed book to a digital e-book, each of which can be in a concrete
situation addressed in various 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 1100 D cameras with EF-S 1855mm 1:3.5-5.6 IS kit lens. It can scan books of up to A4 page size.
The post-processing in this setup is based on a semi-automated transfer of files to a GNU/Linux
personal computer and on the use of free software for image editing, optical character recognition
and finalization of an e-book file. It was initially developed for the HAIP festival in Ljubljana in
2011 and perfected later at MaMa in Zagreb and Leuphana University in Lüneburg.
Public Library scanner is characterized by a somewhat less automated yet distributed scanning
process than highly automated and sophisticated scanner hacks developed at various hacklabs. A
brief overview of one such scanner, developed at the Hacker Space Bruxelles, is also included in
this manual.
The Public Library scanning process proceeds thus in following discrete steps:
1. creating digital images of pages of a book,
2. manual transfer of image files to the computer for post-processing,
3. automated renaming of files, ordering of even and odd pages, rotation of images and upload to a
cloud storage,
4. manual transformation of source images into .tiff files in ScanTailor
5. manual optical character recognition and creation of PDF files in gscan2pdf
The detailed description of the Public Library scanning process follows below.
The Bruxelles hacklab scanning process
For purposes of comparison, here we'll briefly reference the scanner built by the Bruxelles hacklab
(http://hackerspace.be/ScanBot). It is a dual camera design too. With some differences in hardware functionality
(Bruxelles scanner has automatic turning of pages, whereas Public Library scanner has manual turning of pages), the
fundamental difference between the two is in the post-processing - the level of automation in the transfer of images
from the cameras and their transformation into PDF or DjVu e-book format.
The Bruxelles scanning process is different in so far as the cameras are operated by a computer and the images are
automatically transferred, ordered and made ready for further post-processing. The scanner is home-brew, but the
process is for advanced DIY'ers. If you want to know more on the design of the scanner, contact Michael Korntheuer at
contact@hackerspace.be.
The scanning and post-processing is automated by a single Python script that does all the work
http://git.constantvzw.org/?
p=algolit.git;a=tree;f=scanbot_brussel;h=81facf5cb106a8e4c2a76c048694a3043b158d62;hb=HEAD
The scanner uses two Canon point and shoot cameras. Both cameras are connected to the PC with USB. They both run
PTP/CHDK (Canon Hack Development Kit). The scanning sequence is the following:
1. Script sends CHDK command line instructions to the cameras
2. Script sorts out the incoming files. This part is tricky. There is no reliable way to make a distinction between the left
and right camera, only between which camera was recognized by USB first. So the protocol is to always power up the
left camera first. See the instructions with the source code.
3. Collect images in a PDF file
4. Run script to OCR a .PDF file to plain .TXT file: http://git.constantvzw.org/?
p=algolit.git;a=blob;f=scanbot_brussel/ocr_pdf.sh;h=2c1f24f9afcce03520304215951c65f58c0b880c;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 a computer, however this can be done only with a certain number of Canon cameras
(http://bit.ly/16xhJ6b) that can be hacked to run the open Canon Hack Development Kit firmware
(http://chdk.wikia.com).
After transferring the files, you want to erase all the image files on the camera memory card, so that
they would not end up messing up the scan of the next book.
b) Renaming image files
As the left and right camera are typically operated in sync, the photographing process results in two
separate sets of images, with even and odd pages respectively, that have completely different file
names and potentially same time stamps. So before you collate the page images in the order how
they appear in the book, you want to rename the files so that the first image comes from the right
camera, the second from the left camera, the third comes again from the right camera and so on.
You probably want to do a batch renaming, where your right camera files start with n and are offset
by an increment of 2 (e.g. page_0000.jpg, page_0002.jpg,...) and your left camera files start with
n+1 and are also offset by an increment of 2 (e.g. page_0001.jpg, page_0003.jpg,...).
Batch renaming can be completed either from your file manager, in command line or with a number
of GUI applications (e.g. GPrename, rename, cuteRenamer on GNU/Linux).
c) Rotating image files
Before you collate the renamed files, you might want to rotate them. This is a step that can be done
also later in the post-processing (see below), but if you are automating or scripting your steps this is
a practical place to do it. The images leaving your cameras will be positioned horizontally. In order
to position them vertically, the images from the camera on the right will have to be rotated by 90
degrees counter-clockwise, the images from the camera on the left will have to be rotated by 90
degrees clockwise.
Batch rotating can be completed in a number of photo-processing tools, in command line or
dedicated applications (e.g. Fstop, ImageMagick, Nautilust Image Converter on GNU/Linux).
d) Collating images into a single batch
Once you're done with the renaming and rotating of the files, you want to collate them into the same
folder for easier manipulation later.
Getting the image files ready for post-processing on the Public Library scanner
In the case of Public Library scanner, a custom C++ script was written by Mislav Stublić to
facilitate the transfer, renaming, rotating and collating of the images from the two cameras.
The script prompts the user to place into the card reader the memory card from the right camera
first, gives a preview of the first and last four images and provides an entry field to create a subfolder in a local cloud storage folder (path: /home/user/Copy).
It transfers, renames, rotates the files, deletes them from the card and prompts the user to replace the
card with the one from the left camera in order to the transfer the files from there and place them in
the same folder. The script was created for GNU/Linux system and it can be downloaded, together
with its source code, from: https://copy.com/nLSzflBnjoEB
If you have other cameras than Canon, you can edit the line 387 of the source file to change to the
naming convention of your cameras, and recompile by running the following command in your
terminal: "gcc scanflow.c -o scanflow -ludev `pkg-config --cflags --libs gtk+-2.0`"
In the case of Hacker Space Bruxelles scanner, this is handled by the same script that operates the cameras that can be
downloaded from: http://git.constantvzw.org/?
p=algolit.git;a=tree;f=scanbot_brussel;h=81facf5cb106a8e4c2a76c048694a3043b158d62;hb=HEAD
III. TRANSFORMATION OF SOURCE IMAGES INTO .TIFFS
Images transferred from the cameras are high definition full color images. You want your cameras
to shoot at the largest possible .jpg resolution in order for resulting files to have at least 300 dpi (A4
at 300 dpi requires a 9.5 megapixel image). In the post-processing the size of the image files needs
to be reduced down radically, so that several hundred images can be merged into an e-book file of a
tolerable size.
Hence, the first step in the post-processing is to crop the images from cameras only to the content of
the pages. The surroundings around the book that were captured in the photograph and the white
margins of the page will be cropped away, while the printed text will be transformed into black
letters on white background. The illustrations, however, will need to be preserved in their color or
grayscale form, and mixed with the black and white text. What were initially large .jpg files will
now become relatively small .tiff files that are ready for optical character recognition process
(OCR).
These tasks can be completed by a number of software applications. Our manual will focus on one
that can be used across all major operating systems -- ScanTailor. ScanTailor can be downloaded
from: http://scantailor.sourceforge.net/. A more detailed video tutorial of ScanTailor can be found
here: http://vimeo.com/12524529.
ScanTailor: from a photograph of a page to a graphic file ready for OCR
Once you have transferred all the photos from cameras to the computer, renamed and rotated them,
they are ready to be processed in the ScanTailor.
1) Importing photographs to ScanTailor
- start ScanTailor and open ‘new project’
- for ‘input directory’ chose the folder where you stored the transferred and renamed photo images
- you can leave ‘output directory’ as it is, it will place your resulting .tiffs in an 'out' folder inside
the folder where your .jpg images are
- select all files (if you followed the naming convention above, they will be named
‘page_xxxx.jpg’) in the folder where you stored the transferred photo images, and click 'OK'
- in the dialog box ‘Fix DPI’ click on All Pages, and for DPI choose preferably '600x600', click
'Apply', and then 'OK'
2) Editing pages
2.1 Rotating photos/pages
If you've rotated the photo images in the previous step using the scanflow script, skip this step.
- Rotate the first photo counter-clockwise, click Apply and for scope select ‘Every other page’
followed by 'OK'
- Rotate the following photo clockwise, applying the same procedure like in the previous step
2.2 Deleting redundant photographs/pages
- Remove redundant pages (photographs of the empty cradle at the beginning and the end of the
book scanning sequence; book cover pages if you don’t want them in the final scan; duplicate pages
etc.) by right-clicking on a thumbnail of that page in the preview column on the right side, selecting
‘Remove from project’ and confirming by clicking on ‘Remove’.
# If you by accident remove a wrong page, you can re-insert it by right-clicking on a page
before/after the missing page in the sequence, selecting 'insert after/before' (depending on which
page you selected) and choosing the file from the list. Before you finish adding, it is necessary to
again go through the procedure of fixing DPI and Rotating.
2.3 Adding missing pages
- If you notice that some pages are missing, you can recapture them with the camera and insert them
manually at this point using the procedure described above under 2.2.
3) Split pages and deskew
Steps ‘Split pages’ and ‘Deskew’ should work automatically. Run them by clicking the ‘Play’ button
under the 'Select content' function. This will do the three steps automatically: splitting of pages,
deskewing and selection of content. After this you can manually re-adjust splitting of pages and deskewing.
4) Selecting content
Step ‘Select content’ works automatically as well, but it is important to revise the resulting selection
manually page by page to make sure the entire content is selected on each page (including the
header and page number). Where necessary, use your pointer device to adjust the content selection.
If the inner margin is cut, go back to 'Split pages' view and manually adjust the selected split area. If
the page is skewed, go back to 'Deskew' and adjust the skew of the page. After this go back to
'Select content' and readjust the selection if necessary.
This is the step where you do visual control of each page. Make sure all pages are there and
selections are as equal in size as possible.
At the bottom of thumbnail column there is a sort option that can automatically arrange pages by
the height and width of the selected content, making the process of manual selection easier. The
extreme differences in height should be avoided, try to make selected areas as much as possible
equal, particularly in height, across all pages. The exception should be cover and back pages where
we advise to select the full page.
5) Adjusting margins
For best results select in the previous step content of the full cover and back page. Now go to the
'Margins' step and set under Margins section both Top, Bottom, Left and Right to 0.0 and do 'Apply
to...' → 'All pages'.
In Alignment section leave 'Match size with other pages' ticked, choose the central positioning of
the page and do 'Apply to...' → 'All pages'.
6) Outputting the .tiffs
Now go to the 'Output' step. Ignore the 'Output Resolution' section.
Next review two consecutive pages from the middle of the book to see if the scanned text is too
faint or too dark. If the text seems too faint or too dark, use slider Thinner – Thicker to adjust. Do
'Apply to' → 'All pages'.
Next go to the cover page and select under Mode 'Color / Grayscale' and tick on 'White Margins'.
Do the same for the back page.
If there are any pages with illustrations, you can choose the 'Mixed' mode for those pages and then
under the thumb 'Picture Zones' adjust the zones of the illustrations.
Now you are ready to output the files. Just press 'Play' button under 'Output'. Once the computer is
finished processing the images, just do 'File' → 'Save as' and save the project.
IV. OPTICAL CHARACTER RECOGNITION
Before the edited-down graphic files are finalized as an e-book, we want to transform the image of
the text into an actual text that can be searched, highlighted, copied and transformed. That
functionality is provided by Optical Character Recognition. This a technically difficult task dependent on language, script, typeface and quality of print - and there aren't that many OCR tools
that are good at it. There is, however, a relatively good free software solution - Tesseract
(http://code.google.com/p/tesseract-ocr/) - that has solid performance, good language data and can
be trained for an even better performance, although it has its problems. Proprietary solutions (e.g.
Abby FineReader) sometimes provide superior results.
Tesseract supports as input format primarily .tiff files. It produces a plain text file that can be, with
the help of other tools, embedded as a separate layer under the original graphic image of the text in
a PDF file.
With the help of other tools, OCR can be performed also against other input files, such as graphiconly PDF files. This produces inferior results, depending again on the quality of graphic files and
the reproduction of text in them. One such tool is a bashscript to OCR a ODF file that can be found
here: https://github.com/andrecastro0o/ocr/blob/master/ocr.sh
As mentioned in the 'before scanning' section, the quality of the original book will influence the
quality of the scan and thus the quality of the OCR. For a comparison, have a look here:
http://www.paramoulipist.be/?p=1303
Once you have your .txt file, there is still some work to be done. Because OCR has difficulties to
interpret particular elements in the lay-out and fonts, the TXT file comes with a lot of errors.
Recurrent problems are:
- combinations of specific letters in some fonts (it can mistake 'm' for 'n' or 'I' for 'i' etc.);
- headers become part of body text;
- footnotes are placed inside the body text;
- page numbers are not recognized as such.
V. CREATING A FINALIZED E-BOOK FILE
After the optical character recognition has been completed, the resulting text can be merged with
the images of pages and output into an e-book format. While increasingly the proper e-book file
formats such as ePub have been gaining ground, PDFs still remain popular because many people
tend to read on their computers, and they retain the original layout of the book on paper including
the absolute pagination needed for referencing in citations. DjVu is also an option, as an alternative
to PDF, used because of its purported superiority, but it is far less popular.
The export to PDF can be done again with a number of tools. In our case we'll complete the optical
character recognition and PDF export in gscan2pdf. Again, the proprietary Abbyy FineReader will
produce a bit smaller PDFs.
If you prefer to use an e-book format that works better with e-book readers, obviously you will have
to remove some of the elements that appear in the book - headers, footers, footnotes and pagination.
This can be done earlier in the process of cropping down the original .jpg image files (see under III)
or later by transforming the PDF files. This can be done in Calibre (http://calibre-ebook.com) by
converting the PDF into an ePub, where it can be further tweaked to better accommodate or remove
the headers, footers, footnotes and pagination.
Optical character recognition and PDF export in Public Library workflow
Optical character recognition with the Tesseract engine can be performed on GNU/Linux by a
number of command line and GUI tools. Much of those tools exist also for other operating systems.
For the users of the Public Library workflow, we recommend using gscan2pdf application both for
the optical character recognition and the PDF or DjVu export.
To do so, start gscan2pdf and open your .tiff files. To OCR them, go to 'Tools' and select 'OCR'. In
the dialog box select the Tesseract engine and your language. 'Start OCR'. Once the OCR is
finished, export the graphic files and the OCR text to PDF by selecting 'Save as'.
However, given that sometimes the proprietary solutions produce better results, these tasks can also
be done, for instance, on the Abbyy FineReader running on a Windows operating system running
inside the Virtual Box. The prerequisites are that you have both Windows and Abbyy FineReader
you can install in the Virtual Box. If using Virtual Box, once you've got both installed, you need to
designate a shared folder in your Virtual Box and place the .tiff files there. You can now open them
from the Abbyy FineReader running in the Virtual Box, OCR them and export them into a PDF.
To use Abbyy FineReader transfer the output files in your 'out' out folder to the shared folder of the
VirtualBox. Then start the VirtualBox, start Windows image and in Windows start Abbyy
FineReader. Open the files and let the Abbyy FineReader read the files. Once it's done, output the
result into PDF.
VI. CATALOGING AND SHARING THE E-BOOK
Your road from a book on paper to an e-book is complete. If you want to maintain your library you
can use Calibre, a free software tool for e-book library management. You can add the metadata to
your book using the existing catalogues or you can enter metadata manually.
Now you may want to distribute your book. If the work you've digitized is in the public domain
(https://en.wikipedia.org/wiki/Public_domain), you might consider contributing it to the Gutenberg
project
(http://www.gutenberg.org/wiki/Gutenberg:Volunteers'_FAQ#V.1._How_do_I_get_started_as_a_Pr
oject_Gutenberg_volunteer.3F ), Wikibooks (https://en.wikibooks.org/wiki/Help:Contributing ) or
Arhive.org.
If the work is still under copyright, you might explore a number of different options for sharing.
QUICK WORKFLOW REFERENCE FOR SCANNING AND
POST-PROCESSING ON PUBLIC LIBRARY SCANNER
I. PHOTOGRAPHING A PRINTED BOOK
0. Before you start:
- loosen the book binding by opening it wide on several places
- switch on the scanner
- set up the cameras:
- place cameras on tripods and fit them tigthly
- plug in the automatic chargers 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 following the convention
page_0001.jpg, page_0003.jpg, page_0005.jpg... -- and the files from the left camera
following the convention page_0002.jpg, page_0004.jpg, page_0006.jpg...
- collate image files into a single folder
- before ejecting each card, delete all the photo files on the card
- if using the scanflow script:
- start the script on the computer
- place the card from the right camera into the card reader
- enter the name of the destination folder following the convention
"Name_Surname_Title_of_the_Book" and transfer the files
- repeat with the other card
- script will automatically transfer the files, rename, rotate, collate them in proper
order and delete them from the card
III. Transformation of source images into .tiffs
ScanTailor: from a photograph of page to a graphic file ready for OCR
1) Importing photographs to ScanTailor
- start ScanTailor and open ‘new project’
- for ‘input directory’ chose the folder where you stored the transferred photo images
- you can leave ‘output directory’ as it is, it will place your resulting .tiffs in an 'out' folder
inside the folder where your .jpg images are
- select all files (if you followed the naming convention above, they will be named
‘page_xxxx.jpg’) in the folder where you stored the transferred photo images, and click
'OK'
- in the dialog box ‘Fix DPI’ click on All Pages, and for DPI choose preferably '600x600',
click 'Apply', and then 'OK'
2) Editing pages
2.1 Rotating photos/pages
If you've rotated the photo images in the previous step using the scanflow script, skip this step.
- rotate the first photo counter-clockwise, click Apply and for scope select ‘Every other
page’ followed by 'OK'
- rotate the following photo clockwise, applying the same procedure like in the previous
step
2.2 Deleting redundant photographs/pages
- remove redundant pages (photographs of the empty cradle at the beginning and the end;
book cover pages if you don’t want them in the final scan; duplicate pages etc.) by rightclicking on a thumbnail of that page in the preview column on the right, selecting ‘Remove
from project’ and confirming by clicking on ‘Remove’.
# If you by accident remove a wrong page, you can re-insert it by right-clicking on a page
before/after the missing page in the sequence, selecting 'insert after/before' and choosing the file
from the list. Before you finish adding, it is necessary to again go the procedure of fixing DPI and
rotating.
2.3 Adding missing pages
- If you notice that some pages are missing, you can recapture them with the camera and
insert them manually at this point using the procedure described above under 2.2.
3)
Split pages and deskew
- Functions ‘Split Pages’ and ‘Deskew’ should work automatically. Run them by
clicking the ‘Play’ button under the 'Select content' step. This will do the three steps
automatically: splitting of pages, deskewing and selection of content. After this you can
manually re-adjust splitting of pages and de-skewing.
4)
Selecting content and adjusting margins
- Step ‘Select content’ works automatically as well, but it is important to revise the
resulting selection manually page by page to make sure the entire content is selected on
each page (including the header and page number). Where necessary use your pointer device
to adjust the content selection.
- If the inner margin is cut, go back to 'Split pages' view and manually adjust the selected
split area. If the page is skewed, go back to 'Deskew' and adjust the skew of the page. After
this go back to 'Select content' and readjust the selection if necessary.
- This is the step where you do visual control of each page. Make sure all pages are there
and selections are as equal in size as possible.
- At the bottom of thumbnail column there is a sort option that can automatically arrange
pages by the height and width of the selected content, making the process of manual
selection easier. The extreme differences in height should be avoided, try to make
selected areas as much as possible equal, particularly in height, across all pages. The
exception should be cover and back pages where we advise to select the full page.
5) Adjusting margins
- Now go to the 'Margins' step and set under Margins section both Top, Bottom, Left and
Right to 0.0 and do 'Apply to...' → 'All pages'.
- In Alignment section leave 'Match size with other pages' ticked, choose the central
positioning of the page and do 'Apply to...' → 'All pages'.
6) Outputting the .tiffs
- Now go to the 'Output' step.
- Review two consecutive pages from the middle of the book to see if the scanned text is
too faint or too dark. If the text seems too faint or too dark, use slider Thinner – Thicker to
adjust. Do 'Apply to' → 'All pages'.
- Next go to the cover page and select under Mode 'Color / Grayscale' and tick on 'White
Margins'. Do the same for the back page.
- If there are any pages with illustrations, you can choose the 'Mixed' mode for those
pages and then under the thumb 'Picture Zones' adjust the zones of the illustrations.
- To output the files press 'Play' button under 'Output'. Save the project.
IV. Optical character recognition & V. Creating a finalized e-book file
If using all free software:
1) open gscan2pdf (if not already installed on your machine, install gscan2pdf from the
repositories, Tesseract and data for your language from https://code.google.com/p/tesseract-ocr/)
- point gscan2pdf to open your .tiff files
- for Optical Character Recognition, select 'OCR' under the drop down menu 'Tools',
select the Tesseract engine and your language, start the process
- once OCR is finished and to output to a PDF, go under 'File' and select 'Save', edit the
metadata and select the format, save
If using non-free software:
2) open Abbyy FineReader in VirtualBox (note: only Abby FineReader 10 installs and works with some limitations - under GNU/Linux)
- transfer files in the 'out' folder to the folder shared with the VirtualBox
- point it to the readied .tiff files and it will complete the OCR
- save the file
REFERENCES
For more information on the book scanning process in general and making your own book scanner
please visit:
DIY Book Scanner: http://diybookscannnner.org
Hacker Space Bruxelles scanner: http://hackerspace.be/ScanBot
Public Library scanner: http://www.memoryoftheworld.org/blog/2012/10/28/our-belovedbookscanner/
Other scanner builds: http://wiki.diybookscanner.org/scanner-build-list
For more information on automation:
Konrad Voeckel's post-processing script (From Scan to PDF/A):
http://blog.konradvoelkel.de/2013/03/scan-to-pdfa/
Johannes Baiter's automation of scanning to PDF process: http://spreads.readthedocs.org
For more information on applications and tools:
Calibre e-book library management application: http://calibre-ebook.com/
ScanTailor: http://scantailor.sourceforge.net/
gscan2pdf: http://sourceforge.net/projects/gscan2pdf/
Canon Hack Development Kit firmware: http://chdk.wikia.com
Tesseract: http://code.google.com/p/tesseract-ocr/
Python script of Hacker Space Bruxelles scanner: http://git.constantvzw.org/?
p=algolit.git;a=tree;f=scanbot_brussel;h=81facf5cb106a8e4c2a76c048694a3043b158d62;hb=HEA
D