Photosynth of Bahen

The original post that I put up about the Synth that I made can be found here:

Here are the synths of Bahen’s exterior and Bahen’s Lobby

The motivation behind doing this was to give students a “virtual tour” of Bahen for when we went on highschool visits.  Instead of doing a video tour (time-intensive) or a photo slideshow tour (kinda boring), I thought that Photosynth would be a very cool way to show BA to students.   Plus, scrolling through the Synths is just damn cool!

But before we go any further, let’s just go through a brief background on Photosynth.  Photosynth is a project run by the Microsoft Live Labs.  The project is an extension of the Photo Tourism project, originally created by the University of Washington graduate student Noah Snavely.  So what is Photosynth?  According to their FAQ, Photosynth is:

an entirely new visual medium. Photosynth analyzes a set of photos of a place or an object for similarities each other, and uses that data to estimate where a photo was taken and build a model of the subject. It then re-creates the environment and uses that as a canvas on which to display the photos. Photosynth is available for free at photosynth.com, where you can explore creations from users around the world and build synths of your own.

Basically, Photosynth is able to take a bunch of 2D pictures of a particular building/location, and from there re-construct the original location in 3D.  From there, the user will be able to “navigate” through the photos as if they were really back in the physical location.  And as of August 20th, 2008, Microsoft opened up the project to the public; so users will be able to create their own “synths”.  The only downside is that the entire synth environment will be located on their servers. Currently, there is no way to run the Synths offline/locally on your own computer.

So how do you get started?  First, visit the Photosynth website and take a look at some of the popular Synths that other people have made.  Navigate around and get familiar with the photos that people took to generate their Synth.  Next, I recommend that you watch their “How to Synth” video and read their Photography Guide; both of which can be found here.

Second, gather up your equipment.  You’ll definately need a digital camera with a big memory card.  You probably won’t need to go all out on the digital camera part; I used my point-and-shoot Canon Powershot SD790 IS with image quality set to super-fine.  You can probably go all DSLR, but remeber, you’re going to have to upload these images to the Microsoft server, so 10mb per photo x 200 photos will take you a long time. Having a large memory card is probably more important.  You’ll need to take over 200 + photos of any particular location in order to get a good “synth”, so be prepared be very trigger-happy.  I took 262 photos for the Bahen exterior synth, and 148 photos for the Bahen lobby synth; so don’t be camera shy!  You’ll look like a tourist and people will think you’re weird, but you have got to get all those angles in order to get a good synth.

As a final option, you may want to bring a tripod or monopod along with you when you shoot your Synths.  This will go a long way to ensure that your photos are level and that you can get maximum coverage with respect to angles.

Now that you’ve gathered up your gear, let’s start synthing! Make sure you go ahead and do this on a good day, especially if you’re doing outdoor Synths. Here, I’ll go through the process of how I shot the Bahen exterior Synth:

View Bahen Photosynth Path in a larger map
The green path above is my route up and down St.George Street as I took photos. Starting at the south-east corner, I took a set of panoramic pictures at approximately once every 10 meters.  As I reached the north-east corner of Bahen, I crossed back across the street and moved south, repeating the same process.  By doing the same set of shots a second time, but closer to Bahen, you should be able to “zoom” in on the building in the final Synth.  Make sure you try to do all of your shots in one sitting.  I know its a tedious process, but if you seperate ur photo sessions, your final synth will contain pictures of your building with inconsistent lighting and weather.

Now that you’ve got all your photos, you can upload the images to the Microsoft server.  Its essentially a step-by-step process which you can follow here.  I think the app is Windows only; so to all you Mac and Linux users, I think its time to heal those wounded relationships with all your Windows friends.

And that’s it, Photosynth really is that easy.  The hardest part is getting a consistent set of photos that cover all the angles of your Synth environment.  Practice really does make perfect in this case, so go out there, and happy Synth-ing!