I’ve put up the CleVR AS3 libraries on RIAForge, where you can download them as a zip file, or use the svn repository.

The library includes a number of classes that we developed as part of the CleVR Stitcher. They include a set of matrix algebra classes, ported from the Java JAMA library. These let you do standard matrix algebra stuff, and includes support for singular value decomposition and QR decomposition.

There’s also some graphics classes. One is a subclass of BitmapData that adds bicubic and bilinear interpolation. Another is a class for calculating the histogram of an image, with methods to do histogram stretching. This gives results similar to “Auto levels” in Photoshop, or “Enhance” in iPhoto.

You will find them here. They’re released under the Creative Commons attribution licence, which basically lets you do anything with them, so long as you give credit somewhere. A link to clevr.com would usually suffice. Let me know if you have any comments, patches, or if you’re using it.

I’ve just pushed out an update to the CleVR Stitcher which is probably the biggest improvement yet. Loads more features, loads of bugs fixed and a much nicer interface. You will find all the details here: CleVR panoramic photo Stitcher. As always, it’s totally free. Let me know what you think.

I decided to enter it into the Adobe AIR Developer Derby. It’s hard to judge its chances, but I’d love to win that squishy stress ball. If they’re going on innovation, I’d say they’d be hard-pressed to find an AIR app that is pushing the boundaries more than this. In terms of using AIR technologies, we’re using almost all of them! We’ll wait and see…

Yesterday’s update to the CleVR Stitcher has a number of new features. One of these is image enhancement for the finished panorama. This corrects under- or over-exposed images, and works in a similar way to “Auto levels” in Photoshop, or Enhance in iPhoto. See below for more details and a demo.
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For the second release of utility code from CleVR Stitcher, the Adobe AIR panoramic photo stitcher, I’m offering our InterpolatedBitmapData class.
The class adds support for bicubic and bilinear interpolation to the Actionscript BitmapData class. It adds two public methods – getPixelBilinear and getPixelBicubic. You can call these with sub-pixel coordinates and it will interpolate the RGB value for that point. This should be useful for anyone doing more complex transformations than those offered by the Matrix class. I hope it will be useful to someone. Do let me know if you’re using it. As ever, a link back to clevr.com is appreciated but not required.

Download it as part of the CleVR Actionscript Library

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

Update: The CleVR Stitcher can now be found at http://www.clevr.com/stitcher

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The Stitcher is the oldest part of CleVR, originally developed nearly four years ago, so it’s needing an upgrade. It was developed in Java, delivered by Web Start, a system that I’ve never been happy with. I decided that the best plan for the new version was to rewrite it from scratch. It’s a Flex-based Adobe AIR app. AIR, formerly called Apollo, is a new cross-platform runtime under development by Adobe. The first beta was released earlier this month, and it’s a joy to develop for. I’m pleased to announce the first alpha version of the new AIR-based CleVR Stitcher. You’ll need a CleVR account to use it. It’s free, and only takes a couple of minutes to sign up.

The choice for the development platform will be surprising to many people. The idea of doing computer vision and image processing in Flash sounds like madness, but the advances in Flash Player 9 make it possible. While developing the CleVR panorama viewer, it became apparent to me quite how powerful some of the new features were, and the performance improvements in the new Player have made it feasible. The current version is slower than the Java stitcher, but there’s a lot more optimisation that I can do, and it’s certainly usable.

Currently it’s missing a number of features from the Java version, most importantly the ability to repair failed stitches. However, I’ve made several improvements to the algorithms, so there should be fewer failed stitches. The repair facility will be added in a future release, as will several other useful features.

Give it a try, and let me know of any bugs that you find, and any other comments that you have.