When Written: Aug 2008
The other day Microsoft launched ‘Photosynth’, which is an interesting way of taking a bunch of photos and producing a 3D world from them. The results can be very impressive, enabling the viewer to browse and ‘walk’ around a scene, all on-line. To handle the problem of displaying high resolution images on the web and allowing the viewer to zoom into them Photosynth uses the ‘Deep Zoom’ technology built into Silverlight. Currently your Photosynth project has to be hosted on the Microsoft Live servers, although apparently there is plan to make the server side code available. So what do you need to do to make your own ‘Synth?
The first stage is obviously to take some photos, this is the most important stage to get right, and is surprisingly tricky. Photosynth will still work but the best results will only occur if you take the right sort of photos. Photosynth uses textures to identify similar features so, as I found, a flat surface with writing on does not get identified correctly. Your photos need to overlap so that the software can work out the correct order and you need a lot if the area that you are trying to cover is large, and if it’s not large then the whole point of a Photosynth project is rather lost. I went down to listen to a talk by James Glossop who is the Times Young Photographer of the Year 2008 and who had carried out some experiments with Photosynth. We then were armed with Nikon D60 cameras and treated to a trip on the London Eye with the aim to make a community Photosynth project. The result of this you can see at xxxxxxxx. I’m afraid that currently Mac users will not be able to view these. The reason for this is that the technology makes extensive use of DirectX and there are no DirectX drivers for Macs. It is hoped that this will be addressed in the not too distant future, in the mean time a rather amusing message was displayed saying that they were ‘sorry but they are not cool enough yet to support Macs’ ( see screen shot ).
This error message has since been replace for a more staid one, shame Microsoft
However when I looked just now I saw that this message has been replaced by a more staid message about it ‘not being supported on your operating system. What a shame, for a moment there Microsoft looked as though they had a sense of humour. This reliance on DirectX is not surprising but if you are running windows in a virtual machine as I do, then if you use Parallels you will find that Photosynth will do not work for the same reason. Help is to hand though as the beta version of VMware Fusion 2 does in fact run Photosynth in a virtual machine on a Mac. Inspired by this fun way of taking photos and attending a large gathering of hot rods and custom cars over the bank holiday weekend, I was inspired to have a go myself. So after going on the World Record breaking cruise ( 647 cars ) the day before, I decided to try and do a ‘Synth of the display area on the public day. I shot some 250 photos and afterwards I loaded these into the free downloadable Photosynth generator program. I did this on a fairly powerful laptop and the processing and upload took six and a half hours and then failed. A second attempt was quicker and uploaded successfully. The result was fun to see ( just do a search for NATS on www.photosynth.com ). After you have successful uploaded your images the web site will tell you how good a match the software managed across your photos. This value is called ‘Synthy’ and one aims for 100% synth. My first attempt was 11%, not good, for such a large area I obviously need to take more photos 250 was not enough!
My first attempt at a Photosynth project
The need to take lots of ‘snapshots’ I found a very unsatisfactory way to take photos as I normally prefer to take my time and compose a shot, perhaps my training in the earlier days with film cameras? It got me thinking about ways of getting a lot of photos, obviously a community project where several people supply photos to a ‘synth could be a fun way of producing one, but it still would be problematical that is would produce a good ‘synth as most people would probably take similar views rather than the less interesting shots that are necessary to join up the rest. Thinking back to Jon Honeyball’s article a few issues ago about the very high res Red video camera which are either 3K or 5K lines. The individual frames from these cameras are the same quality as most digital still cameras, so a quick pan with one of these cameras would product all the ‘boring images that the ‘synth would need. The ability to build a realistic 3D world from individual photos is one of those applications that is waiting for people to explore its possibilities. Perhaps this technique could be used for recording car accident scenes, enabling the services to clear the roads more quickly; now that would be a good use of this technology. The London Eye has embraced this Photosynth and have several examples on their web site ( www.londoneye.com/ExploreTheLondonEye/Photosynth ).
The London Eye are using Photosynth on their web site to promote the Eye
It is important to remember that Photosynth is not the same a stitching together photos into a panorama that existing products achieve, but rather it is able to create a 3D representation without using aerial photos or complicated cameras, it is a great way of presenting a large area for exploring to on-line viewers. But no amount of reading will help you to understand it fully, get out there and give it a try. It really is good fun way of displaying your photos, and with 20G of free storage, there is plenty of room for your experiments.
Article by: Mark Newton
Published in: Mark Newton