The Casio QV3000EX has a neat feature for lining up panoramic series. When you set it to panorama mode, after you take a picture, a small strip of the right edge is shown at the left of the LCD display so you can line up the next shot. This can go up to 9 frames per panorama. The exposure that is set on the first frame is carried to all the frames so that there will be no exposure change where the images are joined. The camera will then preview the panorama as a complete scrolling image in the LCD display.

To get a high quality result, you need to use some "stitching" software. The software provided with the camera, unfortunately, is too simple. While it can combine the separate images into one, it has no provision for the cylindrical distortion that is necessary for best results. Without the cylindrical distortion, straight horizontal lines that continue from one frame to another have a sharp angled break at the frame boundary - and there is no possibility of having a gentle fade from one frame to another. Here is a bad example:

I use Panavue Image Assembler (PIA), which can be downloaded and purchased on the web. There are several other highly regarded programs for this purpose.

When the proper cylindrical warping is applied, you get horizontal lines that are curved to meet at the same angle at the frame edges: a panorama that can be scrolled smoothly to any direction of view.

Cylindrical Warp and Blended Stitching

In this example, I have included the top and bottom edges, so you can see the type of warping that is applied to the individual images. If you look at the retaining wall, you can see some scalloping, indicating that the lens focal length chosen for processing (50 mm) doesn't exactly match the zoom setting of the camera. This can easily be changed if it seems unacceptable.

PIA can also do spherical distortion for virtual reality environments and non-distorted stitching for scanning large objects piece meal on your flatbed scanner.

PIA includes a utility for automatically determining the focal length and distortion of your camera in case you do not know them. As long as all the images are taken with the same zoom setting, PIA does an excellent job of automatically stitching the images. It blends the images gradually and automatically adjusts color to hide the join areas. You can also select a manual process in which you set flags on matching points of the adjacent images. The manual process can be eased by use of "flag assistant", which automatically finds the precise matching point in adjacent images once you have placed the flag reasonably close.

Some things still lacking: different types of transforms and adjustments require opening separate "project" files. This can be annoying when you really want to do a series of image adjustments as part of one project. Also, PIA cannot handle mixtures of images with different zoom settings. To get the 360-degree result below, which was made from three smaller panoramas with different zoom settings, I had to first combine the three sets of images into separate panoramas, then manually resize two of them to match the third, and finally stitch the three together.

(You must have the Quicktime player Version 4 plug-in to view these results. Find the player at by clicking on "download the free player"):

Townsquare Quicktime panorama
Right-click here to download so you can view it full-screen (1371 KB).

The manual resizing was done by measuring the size of a common object in the two images on the monitor screen and applying a percent resizing to one of the images. There is a slight error at one join point - can you find it? (The light-colored library building is due west. The join error is northeast, on the pavilion roof approximately above a stone bowl of red flowers.) The exposure changed strongly at this point, due to a cloud passing over and also due to starting a new series of images. The color correction and blending has made the discrepancy essentially invisible.

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[last updated 15 July 2000]