CleVR » Panoramic photography and image stitching blog » Java

Linear algebra and matrix manipulation library for Actionscript 3

matt — Sat, 30 Jun 2007 11:56:05 +0000

While developing the CleVR Stitcher, I needed to do quite a bit of linear algebra. I was disappointed to find that there was no Actionscript library out there for doing this, so I had to write my own. Rather than doing it from scratch, I decided to start with NIST’s Java Matrix library: JAMA, which is in the public domain.

For the benefit of anyone else needing to do stuff like this, I’m releasing the library. It’s not a full port, as I only implemented the stuff that I need. It does however support most regular operations for manipulating real matrices. As well as the normal algebra stuff, it includes classes for singular value decomposition and QR decomposition. I hope others find it useful. Let me know if you’re using it. A link back to clevr.com from your site would be appreciated but is not required.

Download it as part of the CleVR Actionscript Library

1000 panoramas (and a couple of problems)

matt — Fri, 27 Apr 2007 18:49:30 +0000

A few minutes ago, we reached a small milestone: our 1000th panorama, and it’s a beaut. See it below. We’ll soon be on our thousandth user too, which is nice. We have some big news coming up over the next week, so stay tuned.

A couple of less positive things: we appear to have a bug in the stitcher which is causing problems for Mac users with PowerPC. Intel-based Macs seem to be unaffected, as does Windows. This seems to have crept in when we updated our code-signing certificates a few days ago. We’re working on it and hope to have a solution soon.

Update: The PowerPC problem is now fixed. G3, G4 and G5 users rejoice!

Likewise, there is a problem with signups for users with Yahoo email addresses. The Yahoo servers don’t seem to be playing nicely with our password emails, with a lot of them still trying to be delivered. We’re in contact with Yahoo and trying to get it resolved. In the meantime, either try to sign up with a different address, or if you use a Yahoo address and you don’t receive a mail, contact us with the username and email that you used to sign up and we’ll sort it out for you.

Web apps on the desktop

matt — Fri, 03 Nov 2006 12:52:23 +0000

While CleVR is mostly web-based, the Stitcher has always needed to be a desktop app. This is for a number of reasons. Primarily it’s because it needs access to the local filesystem so that you can import your photos. Also, it is processor intensive, so runs best as a native app.

However, it also needs to be tightly-integrated with the server, so that it can handle the uploading, authentication and similar. It also needs to be cross-platform, as we don;t have the resources to develop separate apps for Mac, Windows (and possibly Linux). The current system is pretty good – we use Java Webstart which allows us to launch from the browser, while giving us the access we need to the filesystem and native libraries. However, I’ve never been totally happy with it, and am always looking for a better solution. Luckily, there seem to be some on the way.

The other day, I ran across Adobe Apollo, which looks pretty damn cool. This is still in development, but will allow Flash, Javascript and HTML apps to be deployed on the desktop. That sounds a lot like CleVR to me. From first appearances, it seems to be a much more elegant system than Webstart (and the Java platform in general). The HTML renderer is based on WebKit, which of course makes it even cooler.

This stuff seems to be becoming all the rage at the moment – Pulse Laser has a few more examples. WebKit on Rails looks fun, though we don’t use Ruby here so it’s not massively relevant to us.