In creating PDF flip books – supporting retina displays without crippling the browser


While the iOS platform provides a excellent platform for publishing documents, it also presents a number of problems due to its limitations in memory and CPU. Providing a clear zoom without having to have the end user download very large documents can be a rather tricky problem to deal with. For example, there are limitations to both file sizes as well as image sizes in iOS as outlined by Apple’s developer guidelines.

FlexPaper Zine 2.1.8 implements a new method of sharpening text and image quality further on touch based devices. By creating a grid like structure over the document, the viewer determines what parts of a visible page that needs to be downloaded and downloads only these segments of the page in high resolution. 


To use this new method, simply tick the “optimize publication using PHP” checkbox when publishing your document from the desktop publisher app. 

Have a look at a example PDF document which has been converted to a pdf flip book with support for the grid high res loading method

This method currently requires the server you use to host your documents to support PHP5 (or higher) together with GD. 

Maintaining privacy and securing PDF files online

Most services today offering publishing solutions for PDF documents are today tightly bundling their cloud services with their offerings. While this gives you the option to publish your documents without needing a web site of your own, it is seldom clear what exactly is exchanged and stored by your provider and to what extent they have control of the content you leave on their servers. Questions we typically see arise are:

  • Is your content really deleted after you tell a service provider to delete it?
  • How can the service provider guarantee that it cannot be downloaded and accessed by a third party without your knowledge?
  • What if the service provider later decides to add a new way of charging for your content? 

Privacy in FlexPaper
With FlexPaper, we decided to not go down this route with the software we supply. We think what you do with your documents is your business and that only you should know where and how these documents are made available. None of our servers are involved in the publishing process or in hosting any of the content produced using your PDF documents. We don’t count how many documents you publish nor do we keep track of how many views or downloads you generate with your content. Your content, your business. 

Password protecting PDF content
With our latest version of FlexPaper, which can be downloaded from here, we are also improving the ability to protect your content by introducing content signing. By signing your content, you can decide when and how people access it. You can also add your own server side rules if you wish since our signing files are fully open source. The only requirement is that your server supports PHP 5 or higher.

This also allows you to password protect your document and time stamp your content so that it expires at a desired time. Supplying a custom password will also add a log in prompt to your publication so that you can limit the publication to be viewed to a selected audience. Please note that you will need to keep track of your own passwords. We have no way of recovering a lost password since we have no control over the publishing of your documents. You will need to republish your publication if you loose your password.

What do you think of our new signing functionality? Let us know via twitter or post us an email! We appreciate all feedback!

FlexPaper 2.1.8 Release Notes

We have started distributing FlexPaper 2.1.8 this week. The first build finished is our Desktop Publisher app for FlexPaper Zine (Mac & PC) which can be downloaded from the Zine product page. The PHP/ASP.NET/Java and FlexPaper classic builds will follow during the next few days.

  • FlexPaper Zine  enhanced to support higher resolution for touch devices when zooming into the document (requires PHP & GTK2)
  • Issue fixed relating to certain links where they would be incorrectly broken up into sections causing the links to be incomplete when clicked (HTML4/HTML5 mode)
  • Issue fixed for annotations in IE9 when using the HTML rendering mode
  • Last/first navigators added for Zine in HTML4/HTML5 mode
  • FlexPaper Zine Icons added for retina/HD desktop displays (labelled [name]@2x.png)
  • Corrections for hidden text and control characters in exporting to HTML4/HTML5 from desktop publisher [on Windows]
  • Correction for shading in Zine for HTML5/HTML4 (regression issue from 2.1.7)
  • Fixed an issue relating to drag-turning pages in HTML4/HTML5 where the viewer would zoom in unintentionally in some specific scenarios
  • Fixed an issue related to links being created multiple times causing performance degradation in HTML4/HTML5 mode for Zine
  • Performance improvements to sliding and dragging in Zine HTML4/HTML5
  • HTML5 Fisheye thumbnails performance improvements
  • The Viewer is now giving the clicked/tapped page in Zine rendering priority to improve performance while reading
  • Links and custom links made more visible in HTML4/HTML5 mode
  • Regression issue corrected for Zine in relation to loading new documents through the load({PDFFile : ‘filename.pdf’}); API
  • Fixed an issue related to thumbnails showing up incorrectly when in Zoomed in mode in HTML5 mode and resizing the browser window
  • Desktop Publisher now tries to repair PDF files that it fails to publish on first attempt
  • Youtube videos when played in HTML5 viewer will now stop if playing when navigating away from the page
  • Desktop Publisher now able to sign documents and add password protection for your PDF documents to prevent them from being downloaded
  • Issue fixed related to searching for two different phrases causing the search abstracts not appearing the second time in Flash mode for Zine
  • HTML5 PDF rendering routine updated (0.8.633 build # fa03a77)
  • Full screen support added for IE 11 to our HTML4/HTML5 pdf viewer
  • Support for Android in pinch and zoom plus navigation improved for Zine in flip page mode

A case study using PDF flip books: the real state of flash versus HTML5


When Apple and Steve Jobs 3 years ago decided to turn their back on Adobe Flash, the web industry started a major shift towards HTML5 as opposed to using Flash when creating animations and transitions for the web. At that time, many of the modern web browsers were still in a state unable to do everything necessary to really rid Flash out of the way for HTML5. Much has happened since then. 

» Compare HTML5 and Flash performance in some real examples

Development Environment
The latest versions of Google Chrome are blazingly fast in animations and transitions and huge steps has been taken forward in improving the development environment for developers using HTML5 in all major browsers. With Google in the lead, Google has added a whole set of new debugging tools to the latest stable version of Google Chrome. We really recommend you have a look at the Google Developer talks on structural and sampling from Google if you have not done so yet and you are into serious development with HTML5. This talk with Paul Irish is a great starting point if you want to get serious about HTML5 development.


A real world case using PDF flip books : PDF documents with page turn effects in HTML5

So how has this evolution affected our environment for our viewers in creating animated page transitions for published PDF documents? Well much has happened since the first versions of mobile web safari was published and since people started moving into using HTML5. The first versions of mobile web safari had problems displaying larger images and files causing the viewer to really struggle when trying to deliver a sharper zoomed document to these more memory limited devices. 

Since then, mobile safari has matured a great deal and we believe all of the modern versions of all major browsers have reached a point where they are fully capable of displaying our documents with page turn animations and high quality zoom factors. There may still may be individual cases where you think Flash has a upper hand in how a specific document gets displayed due to differences in how these technologies handle vector graphics but we really think that in the majority of cases, our HTML5 viewer actually surpasses the flash viewer in performance!

We really didn’t know how far we would get when we initially started developing our HTML5 viewer but we are amazed at the speed the latest browser versions are showing. We believe that much of the performance gains that will be seen going forward will be due to the incredible development support that these browsers are now giving in terms of profiling. Where Adobe Flash sits on top of the browser, these tools gives us direct access into the core of how the browser is rendering each page turn and every transition operation.  

What do you think?

We would love to hear which of our viewers you think performs best! Have a go with our examples on our demo page or download our flip book software (available for both Mac and PC) and give it a go with your own documents! You can switch between HTML5 and Flash directly on our demo page.


» Try the examples