Spring is either taunting us or announcing its arrival. Either way, I'm not complaining. Last Sunday we took a drive up to the Marin Headlands, and were treated to spectacularly clear views such as what you see below.

The above 360-degree panorama (reduced from an 11428 x 980 pixel original) is composed of 12 shots I took in succession with my Canon Elph. The Elph is a fantastic enough product in and of itself (good features and image quality, yet small enough that it's not a bother to drop in your pocket and take anywhere). But Canon has gone above and beyond by shipping it with a truly excellent panorama stitching app that is very nearly automatic yet produces impressive results. And of course I'm especially pleased that Canon has provided a well-crafted Mac OS X version. :-)

The camera itself has a stitch assist shooting mode whose use of the LCD display helps with getting the successive shots lined up. Images shot in this mode are also tagged with metadata that identifies them as sections of a single panorama. The hardest part about taking a panorama seems to be getting the exposure right. Presumably for consistency, the Elph seems to set its exposure parameters based on the first frame taken. So if you're taking a panorama that includes, say, the Sun, as in the above case, you're going to have to choose which parts of your scene are most important to have properly exposed, and which can be over- or under-exposed, and take aim for the first frame accordingly.

Once you've done the shooting, the process of piecing together the result is incredibly simple:

Step 1. Attach camera and launch Canon's ImageBrowser. ImageBrowser recognizes the series of images taken in stitch assist mode, and highlights them with green stitch marks:

Click once on the stitch marks, and answer that yes, you'd like to merge the images together:

ImageBrowser slurps the needed full-size images from the camera, and launches you into PhotoStitch. Bam. (Well, OK, not quite "Bam", as it takes a while to pull the JPEGs over USB... But the transition into PhotoStitch is automatic at least. :-)

Step 2. With the images automatically arranged in the correct order, there's not much to do here but click the "Merge" tab and then the "Start" button. PhotoStitch makes a best guess at merging the images together, and presents you with a preliminary result:

Step 3. Most often the result of the automatic merge is fine as-is. You're ready to go and save it. This time, for the first time yet, I found a couple of places where things were noticeably misaligned. Part of the horizon wasn't quite lined up, and a cliff to the right of that showed a double image. True to my past experiences with PhotoStitch, however, fixing these problems was easy as pie, even given that I was learning what I needed to do as I went. A "Show Seams" button provides a visual indication of the overlapping regions (the narrow green boxes below):

Clicking on any of these regions brings up (intuitively enough) a panel that prompts you to manually align the adjacent images.

`Oh boy, manual mode. This could be hard to get right,' you think. Not so. All there is to do here is drag one image onto the other, until they line up about right. Due to the different perspective, they will not of course line up exactly, but all you really need to do is eyeball it so that the important noticeable features are more or less properly joined. That's it. No complex interpolation mesh to drag into shape. No need to even rotate the images.

One such adjustment I attempted wreaked a bit of temporary havoc, curling the panorama into an arc, but trying again with the "Auto Adjust Overlap" box unchecked set everything right. For the most part the process is amazingly straightforward and easy.

Step 4. Once you've successfully merged the images into something that looks nice, you have the opportunity to adjust the cropping that's needed to lop off the extra bits at the edges. PhotoStitch generally suggests a reasonable crop rectangle. At worst, it may be overly "safe". You can adjust the suggested crop frame if desired -- say, to reclaim a bit of the edges -- or even save the image without cropping, which produces something like this:

Step 5. Once you've successfully merged the images into something that looks nice, the only step left is to save the result. In addition to the expected option to export as a single flat image (in JPEG, TIFF, BMP, or PICT), you can export as an interactively nagivable QuickTime VR panorama. The latter option is way fun! As an example, I've posted a QTVR version of the above scene. (Broadband connection recommended, as the file is 2.1 MB.) Not too shabby for something that doesn't require high-end software or a special camera rig...

Hats off to the engineers who provided the brains and user experience for this ultra-cool app, and to Canon for supporting their product with such nice Mac OS X tools. They may well sell me my next camera...