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The CodePlex Corner: Seadragon Viewer Web Part

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Introduction

The link to the Project is https://spseadragon.codeplex.com/

The CodePlex project that this discussion is going to look at was originally created by Microsoft Live Labs.  It goes by the name of Seadragon and is a facility that allows a user to perform a “Deep Zoom” on an image.  Don’t worry if that is an unfamiliar term, that term will be explained. Whilst Seadragon was initially a Silverlight project, a separate work stream produced a web based version known as Seadragon Ajax.  Ultimately the team disbanded and the project fell into abandon.  This year a SharePoint Seadragon Viewer web part emerged, which has been developed by Nikolas Charlebois-Laprade.

A short explanation of Deep Zooming is that it is a technology designed to allow efficient viewing and transmission of images.  It consequently works very well with high resolution images.  This is achieved this by breaking up an image into several smaller pieces.  Essentially a pyramid of smaller and lower resolution images is created from the original item.  The starting image is lowest in the pyramid.  When zooming in for sections, you’ll be zooming into one of the tiles from these tile sets, moving between sets as required.

http://baron72.files.wordpress.com/2013/10/102913_1457_thecodeplex1.png?w=614

Believe it or not, it’s something that you’ve probably seen before. If you’re not convinced, take a look at the architecture design pages for SharePoint 2013.  See that zooming ability?  That’s what the Seadragon Viewer does. It makes large and typically unwieldy images much easier to interact with.

When we look at how this works within SharePoint, making the web part work can be broken down into two specific areas: -

  1. Pre-SharePoint work section: the creation of images and their properties with the Deep Zoom Composer 
  2. SharePoint Configuration:  The installation of the web part and how to use Deep Zoom images with the web part

It’s outside the scope of this TechNet review article to explain all of this in great detail but this Wiki article explains the process from start to finish.

There are currently no product reviews on SharePoint Reviews for Seadragon Ajax.  One may be added eventually but as this is only a basic web part and not a fully-fledged solution it would be unfair to add one so soon.  When one is ready is shall be posted under Content Management à Content Organisation and added in a future article update.

“End User – Developer” scale

On first glance this is just a standard web part deployment and installation.  There is however, a fair amount of work to be done to prepare images for Deep Zooming.  For that reason, this web part is rated between the administrator / developer spokes.

http://baron72.files.wordpress.com/2013/10/102913_1457_thecodeplex2.jpg?w=614

Potential pitfalls / problems

This is a web part that makes you work a little to get the most out of it.  As Seadragon and Deep Zooming were never developed with SharePoint in mind, getting the two married together can be an awkward process.  There are two potential potential pitfalls: -

  1. Learning to use the Deep Zoom Image Composer
  2. Setting up the XML and file structure within a Document Library

Using the Deep Zoom Composer: This was originally created as part of the Microsoft Expression Suite but was offered for free rather than being part of the (at the time) paid offering.  Installing it is straight forward enough and exporting the image is a three step process.  You’ll just have to remember to output the files as Seadragon Ajax. 

http://baron72.files.wordpress.com/2013/10/102913_1457_thecodeplex3.png?w=614

Linking it all to the web part: The web part works by communicating with the XML file that is output from the Deep Zoom Viewer.  This will involve renaming the output XML file and the image directory so that they have the same name.  Not a technically challenging step but an easy one to overlook.

Conclusions / Comments

Seadragon is a technology that, when bolted into the  SharePoint product is surprisingly industry agnostic.  It’ll have a use anywhere that a high resolution image can serve a purpose.  Being able to surface this within SharePoint sites seamlessly can be a powerful tool in the web part tool kit.

See Also

References