Douglas Bagnall – Adam Hyde

Booki to Booktype, BookJS and beyond…

Many years ago I was the Product Manager and Project Lead for Booktype at Sourcefabric. We developed many interesting technologies including Booktype itself, Objavi, StyleJS, BookJS, Booktype Renderer, and Booktype Designer, amongst others.

Booktype is still going very well and has also spawned the very interesting Omnibook service. Due to the recent interest in this project, I revisited this old video which documents some of the exploratory thinking I had when leading the Booktype team at Sourcefabric. It was recorded May 2012 at #dev8ed in Birmingham, UK. At the time I was leading a small team, having just migrated Booki (FLOSS Manuals) to Booktype (at Sourcefabric).

I found the video really interesting as it covers my thinking at the time, (developed over many years of experimenting in this area) over many issues, including rendering books in the browser and using the browser as a design environment for books. There are some nice quotes which accurately reflect how I was thinking then which are interesting:

“there is no one taking responsibility for designing environments where you can target both flowable text as an output like Kindle or EPUBS, and at the same time, target fixed page outputs like paper books. So we are trying to work this out at the moment. How do you deal with this? .[…] We are trying to work out how can you possibly find a paradigm that fits both flow-based, and fixed page, design” [36min 25s]

and

“what we want to see [in the browser] is when you are outputting to book-formatted PDF, we want to see like you see in Google Docs – exactly the page dimensions that you are going to get when you output the PDF. Google Docs does some sort of magic where that is possible, we haven’t yet cracked it ourselves, but for fixed page design we think it is quite important that what you see in the HTML page is what you would eventually get in the PDF. [41min 37s]

…

“…how do you actually render one to one representation of a book-formatted PDF in a browser?” [49min 49s]

…

“…we can have JavaScript playing a role in rendering elements of pages for book-formatted PDF.” [16min 58s]

…

“…we take the Booktype content as HTML, HTML as the base format, and Objavi formats that into one long HTML page for which we have specific CSS rules to structure the book in a specific way. Then we run WKHTML over the top of it, and a number of other tools, and we assemble a book out of it, book-formatted PDF” [18min 38s]

…

“Thats because WKHTMLTOPDF is webkit, the browsing engine behind Chrome and Safari, … so you can use CSS, and JavaScript and everything from webkit, and turn it into a PDF” [19min 50s]

…

“…the advantage of using webkit as part of the rendering environment, as webkit is a browser, [is that] if you design in the browser you have a one to one co-relation between content creation environment and output environment” [33 min 49sec]

To be clear, we were already using browser engines to make books for quite some time, and Douglas Bagnall, a friend who also worked with me at FLOSS Manuals, even investigated collaborating with the Gecko (Mozilla layout engine) developers to add widows and orphans controls and the CSS page-break control (which we needed for books), in 2010 or so. Actually, it was pretty cool because Douglas, myself and Robert O’Callahan (Mozilla layout engine dev) were all New Zealanders. But FLOSS Manuals had been making books for many years with browser engines since Behdad Esfahbod advised me to explore this, many years earlier. We knew browsers could be used for producing book-formatted PDF and we had been doing it for years.

However, as I have learned over the years, there is an important role for vision, experimentation, and theoretical exploration prior to developing good software. Hence, I was now exploring how you could take these positions further to design books in the browser client. Rendering PDF was one part of the story, the other was working out the tools to take book design to the browser. This was what Adobe was also after, I believe, when they implemented CSS Regions in webkit and started on their Adobe Edge Reflow line of products that leveraged the browser as a ‘design surface’. They were interesting times.

But back to the Booktype story. The video is a demo in May 2012, about a month before I hired anyone (in June) to start on what eventually became BookJS. It took us a while to get there but after much discussion, further experimentation, and some months of development, I was able to introduce BookJS in Oct 2012 on the Sourcefabric blog.

Terrible profile pic of me!

While BookJS didn’t quite get to be the design environment I was (and still am) after, it was still a good tool. In an attempt to get to a design and rendering solution in the browser, we later took the Booktype Designer (demonstrated in the video) ideas to a JavaScript prototype called StyleJS for integrating with BookJS but, unfortunately, it didn’t make it to production. StyleJS enabled a kind of ‘WYSIWYG’ tool for styling a page live. Which is an interesting prototype for future in browser book production exploration.

Work continued on BookJS and it has had a useful life despite some quirky turns in the road. During this time, the Booktype team worked with several people on the development of BookJS and received good advice and contributions from Mihai Balan (from the Adobe CSS Regions team), Phil Schatz (from Connexions), Maria Fraser (University College London) and others. As with many software projects, contributions like this deserve a lot of credit, as I have written elsewhere, since these contributions are not always preserved in the code.

Another quirk that happened is that the Google team, in an unexpected move which surprised many people and turned into a bit of a CSS heavy hitters ‘discussion’, removed CSS Regions from Blink. Many people were pretty shocked. This, I think (but I don’t know the inside story), spelled the end for Adobe’s vision of the browser as a design surface using CSS Regions, and the Adobe Edge Reflow product has been discontinued.

In the Booktype world, Juan Gutierrez (who worked on BookJS at Sourcefabric, and now works with me at Coko) extended BookJS to support the CSS Regions polyfil. It is still in use now with Book Sprints for rendering books. Consequently, we are still very grateful that Booktype and Sourcefabric kept the BookJS product AGPL after I left the project so we could extend it. Hurray for Open Source!

It is good to see Booktype going strong, Sourcefabric still invested in Open Source, and a growing interest around Omnibook. I know the team there, Micz Flor (co-founder of Sourcefabric and Managing Director of Booktype) being an old friend, and Julian Sorge also makes a great Booktype Managing Director. They have brought their own vision to the Booktype products, pushing them in new directions, and it is really great to see. I’m hoping they will continue to go from strength to strength.

In summary, these were interesting, productive times. Sourcefabric provided the opportunity for Booktype to grow, and I experimented a lot, as I had done at FLOSS Manuals (and continue to do now), with new ideas and approaches. There was some great software, books, and ideas that came out of that period. Some of the books we made I have even kept with me through my travels. In the video, for example, I demonstrate the Booktype Designer. We built the Designer before and during the Sandberg Institute workshop I led in Amsterdam and used it in the same month as I did the presentation to create this wonderful artist’s book. I carried it with me all over the world and still have it on my bookshelf now!

Waag Society/Remko Siemerink 2012. https://creativecommons.org/licenses/by/4.0/

Nice to find this old vid.

Original url for the video: https://vimeo.com/43591376

Review: http://devcsi.ukoln.ac.uk/2012/05/29/dev8ed-workshop-booktype/

Building Book Production Platforms p4

The renderer

Note: this is an early version. It has been cleaned up some, but is still needing links and screenshots…. Apologies if the rawness offends you 🙂

This series is skipping around the toolchain, depending on what’s most in my mind at the moment. Today it’s file conversion, otherwise known as ‘rendering’. This is the process of converting one file type to another, for example, HTML-to-EPUB or Word-to-HTML, and so on.

It’s important to have file conversion in the book production world because we often want to convert the HTML to a book format – like book-formatted PDF, or EPUB, mobi and so on, or to import into a new document existing content contained in a file like MS Word.

Manual conversions

It is, of course, quite possible to do all your file conversion manually.

Should you wish to convert HTML into a nice book-formatted PDF, one possible strategy is to go out to InDesign or Scribus and lay it all out like our ancestors did as recently as 2014. Or, if you want to convert MS Word, for example, to HTML, you can just save it as HTML in Word… Yes, Word copies across a lot of formatting junk, but you can clean it up using purpose-built freely available software (such as HTMLTidy and CleanUp HTML), online services (like DirtyMarkup),or a handy app (such as Word HTML Cleaner)…

Manual conversion is not too bad a strategy, as long as it doesn’t take you too long, and it is often more efficient and faster than those convoluted hand-holding technical systems which promise to do it for you in one step. Despite the utopian promises made by automation… you often get better results doing the conversion manually.

I sometimes hear people in Book Sprints, for example, complain something to the tune of “why can’t I just click a button and import part of this paragraph from Wikipedia into the chapter, and then if the entry is updated in Wikipedia, I can just click the button again and it will be updated here”…

I try not to sigh too loudly when I hear this kind of ‘I have all the solutions!’ kind of ‘question’. Some day that may be feasible, but in the meantime, all the knowledge production platforms I have built have an OS-independent trans-format import mechanism which allows those handy keyboard shortcuts ‘control c’ and ‘control p’… sigh. Don’t knock copy and paste! It can get you a long way.

You can also build an EPUB by hand…

But, who really wants to do any of this? Isn’t it better to just push a button and taaadaaa! out pops the format of choice! (I have all the solutions! haha).

I think we can agree it is better if you are able to use a smart tool to convert your files, and the good news is that within certain parameters and for loads of use cases, this is possible. But don’t under-estimate the amount of tweaking for individual docs that might, at times (not always), be required.

Import and export are the same thing

The process of ‘importing’ a document is also sometimes known as ingestion. Before delving down into this, the first gotcha with file transformation is to avoid thinking about import and export as separate technical systems. That can, and has, caused a lot of extra work when building file conversion into a toolchain.

Both import and export are, actually, file conversion. The formats might differ, import might solely be Word-to-HTML in your system and the export HTML-to-EPUB. However, the process of file conversion has many needs that can be abstracted and applied to both of these cases. A quick example – file conversion is often processor and memory intensive. So effective management of these processes is quite important, and in addition, fallbacks for errors or fails need to be managed nicely. These two measures are required independent of the filetypes you are converting from or to. So don’t think about pipelining specific formats, try and identify as many requirements as possible for building just one file conversion system, not an import system plus an export system.

Ingestion

In importing documents to an HTML system, the big use case is MS Word. Converting from MS Word is a road full of potholes and gotchas. The first problem is that there is no single ‘MS Word’ file format, rather there are many many different file formats that all call themselves MS Word. So to initiate a transformation, you need to know what variety of MS Word you are dealing with.

Your life is made much easier if you can stipulate that your system requires one variety – .docx. If you do have to deal with other forms of Word, then it is possible to do transformations on the backend from miscellaneous Word file type X to .docx and then from .docx to HTML. Libreoffice, for example, offers binaries that do this in a ‘headless’ state (it can be executed from the command line without the need to fire up the GUI). However, the more transformations you undertake, the more errors in the conversion you are likely to introduce. Obviously, this then causes QA issues and will increase your workload per transform required.

Another real problem with MS Word versions before .docx, is that .docx is transparent, actually is just XML. So you can view what you are dealing with. Versions before this were horrible binaries – a big clump of ones and zeros – and after that a bunch of gunk. That same problem also exists when you use binaries like soffice (the Libreoffice binary for headless conversions) as it is also a big bucket of numbers. You can’t easily get your head into improving transformations with soffice unless you want to learn to etch code into your CPU with a protractor.

If you have to deal with MS Word at all, I recommend stipulating .docx as the accepted MS Word format. I am not a file type expert, far from it, but from people who do know a lot about file formats I know that .docx looks like it has been designed by a committee… and possibly, a committee whose members never spoke to each other. Additionally, Microsoft, being Microsoft, likes to bully people into doing things their way. .docx is a notable move away from that strategy, and does make it substantially easier to interoperate with other formats, however, there are some horrible gotchas like .docx having its own non-standard version of MathML. Yikes. So, life in the .docx lane is easier, but not necessarily as easy as it should be if we were all playing in the same sandbox like grownups.

I have tried many strategies for Word to HTML conversion. There are many open source solutions out there, but oddly, not as many good ones as you would hope. Recently I looked at these three rather closely:

Calibre’s Python based ebook converter script
OxGarage
soffice (Libreoffice)

There are others…I can’t even remember which ones I have looked at in detail over the years. I have trawled Sourceforge and Github and Gitorious and other places. But the web is enormous these days and maybe there is just the oh-so-perfect solution that I have missed. If you know it then please email it to me, I’ll be ever so grateful (only Open Source solutions please!).

These three are all good solutions, but at the end of the day, I like OxGarage. I won’t go into too much detail about all of them but a quick top-of-mind whys and why-nots would include:

Calibre’s scripts are awesome and extendable if you know Python, however they don’t support MS MathML to ‘real’ MathML conversions. That’s a show stopper for me.
On the good side, though, Calibre’s developer community is awesome, and they are heroes in this field and deserve support, so if you are a Python coder or dev shop then, by all means, please pitch in and help them improve their .docx to HTML transforms. The world will be a better place for it.
soffice does an ok job but it’s a black box, who knows what magic is inside? It tends to make really complex HTML and it is also really heavy on your poor hardware. I have used it a lot but I’m not that big a fan.
OxGarage…well…I love OxGarage, so I really recommend this option…

OxGarage was developed by a European Commission-funded project and then, as is common for these kinds of projects, it dried up and was left on a shelf. Along came Sebastian Rhatz, a guru of file transformation, big Open Source guy, and also a force behind the Text Encoding Initiative. Sebastian is also the head of Academic IT Sevices at Oxford University. The guy has credentials! Also, he’s a terribly nice and helpful guy. He has so much experience in this area I feel the trivialness of my questions about our .docx to HTML woes at PLOS… afraid he might absentmindedly swipe me out of the way like I was an inconsequential little midge.. but he’s such a nice chap, instead he invites midges out to lunch.

So, Sebastian picked up the Java code and added some better conversions. OxGarage is essentially a Java framework that manages multiple different types of conversions. You feed it and are fed from it by a simple web API. It doesn’t have the best error handling, but it does do a good job. The .docx to HTML conversion is multi-step. First, the .docx is converted to TEI – a very rich, complex markup, and then from TEI via XSL to HTML. That means that all you really need to worry about is tweaking the XSL to improve the transformation and that’s not too tricky. It could be argued that the TEI conversion is a redundant step. I think it is. But OxGarage works out of the box and does a pretty good job so we have adopted it for the project I am working on for PLOS, and we are happy with it. We have added some special (Open) Sauce but I’ll get to that later. We are using it and will shoot for more elegant solutions later (and we have designed a framework to make this an easy future path).

If you are looking for Word-to-HTML conversion tools, I recommend OxGarage. Im not saying it’s the optimal way to do things, but it will save you having to build another file conversion system from scratch, and from what I can tell from Sebastian, that would take considerable effort.

HTML to books

The other side of the tracks is the conversion of the HTML you have into a book file format. We live in a rather tangled semantic world when it comes to this part of the toolchain. Firstly, it’s hard to know what a book file format actually is these days… on a normal day, I would say a book file format is a file format that can display a human readable structured narrative. Yikes. That’s not particularly helpful… Let’s just say for now that a book file format is – EPUB, book formatted PDF, HTML, and Mobi.

So, transforming from HTML to HTML sounds pretty easy. It is! The question is really how do you want your book to appear on the web? Make that decision first, and then build it. Since you are starting with HTML this should be rather easy and could be done in any programming language.

The next easiest is EPUB. EPUB contains the content in HTML files stored in a zip file with the .epub suffix. That is also easy to create and, depending on your programming language, there are plenty of libraries to help you do this. So moving on…

Mobi. Ok.. mobi is a proprietary format and rather horrible. It contains some HTML, some DB stuff… I don’t know… a bit of bad magic, frogs legs… that kind of thing. My recommendation is to first create your EPUB and then use Calibre’s awesome ebook converter script to create the mobi on the backend. Actually, if you use this strategy, you get all the other Calibre output formats for free, including (groan) .docx if you need it. Honestly, go give those Calibre guys all your love, some dev time, and a bit of cash. They are making our world a whole lot easier.

Ok… the holy grail… people still like paper books, and paper books are printed from PDF. Paper these days is a post-digital artifact. So first you need that awkward sounding book-formatted PDF.

Here there are an array of options and then there is this very exciting world that can open to you if you are willing to live a little on the bleeding edge…. I’m referring to CSS Regions… but let’s come back to that.

First, I want to say I am disappointed that some ‘Open Source’ projects use proprietary code for HTML-to-PDF conversion. That includes Press Books and Wikipedia. Wikipedia is re-tooling their entire book-formatted-PDF conversion process to be based on LaTeX and that is an awesome decision. However, right now they use the proprietary PrinceML as does Press Books. I like both projects, but I get a little disheartened when projects with a shared need don’t put some effort into an Open Source solution for their toolchain.

All book production platforms that produce paper books need an HTML-to-PDF renderer to do the job. If it is closed source then I think it needs to be stated that the project is partially Open Source. I’m a stickler for this kind of stuff but also, I am saddened that adoption of proprietary components stops the effort to develop the Open Source solutions we need, while simultaneously enabling proprietary solutions to gain market dominance – which, if you follow the logic through, traps the effort to develop a competitive Open Source solutions in a vicious circle. I wish that more people would try, like the Wikimedia Foundation is trying, to break that cycle.

The browser as renderer

There is one huge Open Source hero in this game. Jacob Truelson. He created WKHTMLTOPDF when he was a university tutor because he wanted his students to be able to write in HTML and give him nicely formatted PDF for evaluation. So he grabbed a headless Webkit, added some QT magic, some tweaks, and made a command line application that converts HTML to book-formatted PDF. We used it in the early days of FLOSS Manuals and it is still one of the renderer choices in the Booktype file conversion suite (Objavi). It was particularly helpful when we needed to produce books in Farsi which contain right to left text. No HTML to PDF renderer supported this at the time except WKHTMLTOPDF because it was based on a browser engine that had RTL support built in.

Some years later WKHTMLTOPDF was floundering, mainly because Jacob was too busy, and I tried to help create a consortium around the project to find developers and finance. However I didn’t have the skills, and there was little interest. Thankfully the problem solved itself over time, and WKHTMLTOPDF is now a thriving project and very much in demand.

WKHTMLTOPDF really does a lot of cool stuff, but more than this, I firmly believe the approach is the right approach. The application uses a browser to render the PDF…that is a HUGE innovation and Jacob should be recognised for it. What this means is – if you are making your book in HTML in the browser, you have at your fingertips lots of really nice tools like CSS and JavaScript. So, for example, you can style your book with CSS or add javaScript to support the rendering of Math, or use typography JavaScripts to do cool stuff… When you render your book to PDF with a browser, you get all that stuff for free. So your HTML authoring environment and your rendering environment are essentially the same thing… I can’t tell you how much that idea excites me. It is just crazy! This means that all those nice JavaScripts you used, and all that nice CSS which gave you really good looking content in the browser will give you the same results when rendered to PDF. This is the right way to do it and there is even more goodness to pile on, as this also means that your rendering environment is standards-based and open source…

Awesome. This is the future. And the future is actually even brighter for this approach than I have stated. If you are looking to create dynamic content – let’s say cool little interactive widgets based on the incredible tangle! Library – for ebooks (including web-based HTML) … if you use a browser to render the PDF you can actually render the first display state of the dynamic content in your PDF. So, if you make an interactive widget, in the paper book you will see the ‘frozen’ version, and in the ebook/HTML version you get the dynamic version – without having to change anything. I tested this a long time ago and I am itching to get my teeth into designing content production tools to do this.

So many things to do. You can get an idea how it works by visiting that Tangle link above… try the interactive widgets in the browser, and then just try printing to PDF using the browser… you can see the same interactive widgets you played with also print nicely in a ‘static’ state. That gets the principle across nicely.

So a browser-based renderer is the right approach, and Prince, which is, it must be pointed out, partly owned by Håkon Wium Lie, is trying to be a browser by any other name. It started with HTML and CSS to PDF conversion and now…oo!… they added Javascript… so…are they a browser? No? I think they are actually building a proprietary browser to be used solely as a rendering engine. It just sounds like a really bad idea to me. Why not drop that idea and contribute to an actual open source browser and use that. And those projects that use Prince, why not contribute to an effort to create browser-based renderers for the book world? It’s actually easier than you think. If you don’t want to put your hands into the innards of WebKit, then do some JavaScript and work with CSS Regions (see below).

This brings us to another part of the browser-as-renderer story, but first I think two other projects need calling out for thanks. Reportlab for a long time was one of the only command line book-formatted-PDF rendering solutions. It was proprietary but had a community license. That’s not all good news, but at least they had one foot in the Open Source camp. However, what really made Reportlab useful was Dirk Holtwick’s Pisa project that provided a layer on top of Reportab so you could convert HTML to book-formatted-PDF.

The bleeding edge

So, to the bleeding edge. CSS Regions is the future for browser-based PDF rendering of all kinds. Interestingly Håkon Wium Lie has said, in a very emphatic way, that CSS Regions is bad for the web…perhaps he means bad for the PrinceML business model? I’m not sure, I can only say he seemed to protest a little too much. As a result, Google pulled CSS regions out of Chrome. Argh.

However CSS Regions are supported in Safari, and in some older versions of Chrome and Chromium (which you can still find online if you snoop around). Additionally, Adobe has done some awesome work in this area (they were behind the original implementation of CSS Regions in WebKit – the browser engine that used to be behind Chrome and which is still used by Safari). Adobe built the CSS Regions polyfil – a javaScript that plays the same role as built-in CSS regions.

When CSS regions came online in early 2012, Remko Siemerink and I experimented with CSS Regions at an event at the Sandberg (Amsterdam) for producing book- formatted PDF. I’m really happy to see that one of these experiments is still online (NB this needs to be viewed in a browser supporting CSS Regions).

It was obviously the solution for pagination on the web, and once you can paginate in the browser, you can convert those web pages to PDF pages for printing. This was the step needed for a really flexible browser-based book-formatted-PDF rendering solution. It must be pointed out however, that it’s not just a good solution for books… at BookSprints.net we use CSS Regions to create a nicely formatted and paginated form in the browser to fill out client details. Then we print it out to PDF and send it…

Adobe is on to this stuff. They seem to believe that the browser is the ‘design surface’ of the future. Which seems to be why they are putting so much effort into CSS Regions. Im not a terribly big fan of InDesign and proprietary Adobe strategies and products, but credit where credit is due. Without Adobe CSS Regions ^^^ would just be an idea, and they have done it all under open source licenses (according to Alan Stearns from Adobe, the Microsoft and IE teams also contributed to this quite substantially).

At the time CSS Regions were inaugurated, I was in charge of a small team building Booktype in Berlin, and we followed on from Remko’s work, grabbed CSS Regions, and experimented with a JavaScript book renderer. In late 2012, book.js was born (it was a small team but I was lucky enough to be able to dedicate one of my team, Johannes Wilm, to the task) and it’s a JavaScript that leverages CSS Regions to create paginated content in the browser, complete with a table of contents, headers, footers, left-right margin control, front matter, title pages…etc… we have also experimented with adding contenteditable to the mix so you can create paginated content, tweak it by editing it directly in the browser, and outputting to PDF. It works pretty well and I have used it to produce 40 or 50 books, maybe more. The Fiduswriter team has since forked the code to pagination.js which I haven’t looked at too closely yet as I’m quite happy with the job book.js does.

CSS Regions is the way to go. It means you can see the book in the browser and then print to PDF and get the exact same results. It needs some CSS wizardry to get it right, but when you get it right, it just works. Additionally, you can compile a browser in a headless state and run it on the command line if you want to render the book on the backend.

Wrapping it all up

There is one part of this story left to be told. If you are going to go down this path, I thoroughly recommend you create an architecture that will manage all these conversion processes and which is relatively agnostic to what is coming in and going out. For Booktype, Douglas Bagnall and Luka Frelih built the original Objavi, which is a Python based standalone system that accepts a specially formatted zip file (booki.zip) and outputs whatever format you need. It manages this by an API, and it serves Booktype pretty well. Sourcefabric still maintains it and it has evolved to Objavi 2.

However, I don’t think it’s the optimal approach. There are many things to improve with Objavi, possibly the most important is that EPUB should be the file format accepted, and then after the conversion process takes place EPUB should be returned to the book production platform with the assets wrapped up inside. If you can do this, you have a standards-based format for conversion transactions, and then any project that wants to can use it. More on this in another post. Enough to say that the team at PLOS are building exactly this and adding on some other very interesting things to make ‘configurable pipelines’ that might take format X though an initial conversion, through a clean up process, and then a text mining process, stash all the metadata in the EPUB and return it to the platform. But that’s a story for another day…

Importing Archive.org Books with Booki

For some months, Booki has been able to import Archive.org books. This development was sponsored by Archive.org. When importing a book, Booki requests an ePub from Archive.org, converts this to the ‘native file format’ (booki-zip) and loads this into the Booki database. It is then possible to export the same book back into an ePub file.

So, if Booki can import an Archive.org ePub and then export it as ePub what is the point? Seems like Booki is an unnecessary conduit. Well, one point is that with Booki you can export the book into multiple formats – such as book-formatted PDF. That means you can take any of those luscious out-of-copyright books, import them into Booki and make real books from them. This is pretty exciting when you see just how lovely some of these books are. Take for example the copy of Cinderella in the American Libraries section of Archive.org.

Cinderella original edition — Cinderella Edward Dalziel, 1865

This version of Cinderella is out-of-copyright and you can republish as you like. This is a pretty exciting prospect, opening the door for anyone to start their own publishing house importing content from Booki, styling, and exporting to print-formatted-PDF for printing.

However, there are a few steps that you may need to go through first, and this is the real reason why we have implemented importing from Archive.org. All the books in the Archive.org libraries have been created using OCR (Optical Character Recognition) scanning. The process involves loading books onto book scanners and scanning each page.

Archive.org Book Scanner.

However, scanning creates a certain amount of errors. OCR doesn’t render all text correctly and cannot tell the difference between text on a page and text in an image. Hence images with embedded text are usually split up, with the text elements saved as plain text and the surrounding image saved as multiple smaller images. So the OCR-scanned books need proofing and the import feature in Booki enables proofing of OCR scanned books from Archive.org. This means that teams can get together remotely, choose a selection of Archive.org books, and get to work improving them.

While this is all working, we want to build a tighter workflow and a few extra tools to assist the proofing process (if you are a developer familiar with Python and interested in helping us with this good cause then let us know). Douglas Bagnall (Booki/Objavi developer) recently extended the import functionality so that all the metadata imported from Archive.org is preserved. This opens the door to utilising this information to assist proofing of the content – we hope, for example, to eventually be able to show the complete digital image of the original scan, before it was reduced to OCR, alongside the OCR pages to assist proofing. Watch this space!

Incidentally, Booki can import any ePub, so this means that the way is open for the same proofing process to be applied to other OCR scanning projects. If you have a project like this then let us know, maybe we can help.