If you haven’t already, check out Photosynth, the latest release from Livelabs showing off this fantastic technology that stitches images together in 3-D space and lets you navigate your vacation photos. It's better seen than described in words, so don't hesitate to blow off a few minutes looking at the great Synths that have already come in from all over the world.

Well, the wonderful thing about Photosynth and Deep Zoom is that we share the same file format. A collection created in Photosynth can be opened in Deep Zoom and the items in the collection can be arranged to a developer’s liking.

Click below to see the application that lets you view any photosynth collection you may have found and liked, but don’t have a chance to look at because you are using a Mac (like me at home) or because you don’t have a supported browser.


 

How does one open a Photosynth collection?

Well, search for your favorite Photosynth, right click the link and copy it, or copy the URL from the address bar, and paste it into the viewer. The viewer does the rest to open the collection and lay it out on a 2-D grid.

 

 

Some details on the Photosynth format

All this little application really does is analyze the URL to a collection and pull out the right pieces to reconstruct the URL to the actual collection.

Let’s take the following example:

http://photosynth.net/view.aspx?cid=ffa4cce7-d8ec-44f8-9eac-ab28b838cdcb

Is the URL to a photosynth of a collection. The resulting URL to the collection (according to fiddler) is:

http://mslabs-100.vo.llnwd.net/d4/photosynth/M6/collections/ff/a4/cc/ffa4cce7-d8ec-44f8-9eac-ab28b838cdcb.dzc

Note that Photosynth uses the extension “.dzc” (Deep Zoom Collection) for collections, and “.dzi” (Deep Zoom Image) for images.

So what do you need to do to get to the collection given the URL to the Synth? Well, first, you extract the collection GUID (ffa4cce7-d8ec-44f8-9eac-ab28b838cdcb).

Next, you need to construct the path to the collection from the GUID. The first part can always be the same:

http://mslabs-100.vo.llnwd.net/

Next, there is a “d”, followed by a number. This number can’t be derived from the GUID, it’s different for every synth. So I need to try numbers between 2 and 8 to see where the collection is.

The next bit (/photosynth/M6/collections/) is always the same. The next bit (/ff/a4/cc/) is simply the first six digits of the GUID. Then add the GUID, “.dzc” and you are done!

Note on layouts

One thing to note is that Photosynth does not put layout information into the collection XML file. This layout information is normally used by Deep Zoom to place images in a collection on screen in the right spots (Deep Zoom Composer for example fills in the layout information).

So if you attempt to open a Photosynth collection without laying the images out yourself, you will be in a world of hurt - the default behavior for deep zoom when layout information is missing is to layout all the images in a collection fitting to the container deep zoom is in. And since that can be hundreds of images, it can be pretty slow.