CGarchitect reviews REALVIZ® Stitcher® 3.1

Posted by Jeff Mottle 3 February 2002 5:00 pm

REALVIZ®STITCHER® 3.1
By Jeff Mottle (jmottle@cgarchitect.com)

In this, part one, of a three part series, CGarchitect.com will take a look at REALVIZ's® AEC offerings. Our first review will focus on REALVIZ® Stitcher® 3.1, a panoramic stitcher for the web, film, print, and 3D.

Ranked as one of the best panorama stitching programs around, REALVIZ® Stitcher® is a very powerful and feature-rich program that produces consistent and reliable results.
I spent a fair bit of time playing around with Stitcher's® features and was pretty impressed with how easily I could author a 360° panorama. All of my tests were done with a Nikon Coolpix 995 digital camera, and tripod. I should note that I did not use a panoramic head for any of my tests, although it is highly recommended that you do to ensure proper results with no parallax error.

REALVIZ® Stitcher® allows you to author panoramas ranging from 360° cylindrical to spherical 360°x180° QTVR panoramas, by simply taking overlapping pictures in horizontal and/or vertical directions. This can be very useful for creating hi-res background plates for your renderings, generating spherical light probes for renderers like Brazil and VIZ4, and of course for your online virtual tour presentations. Also, if you do not have access to wide angles lenses or a panoramic camera, Stitcher® may be just what you are looking for.

The interface for REALVIZ® Stitcher® consists of two windows: The image strip window and the stitching window. Stitcher's® commands are easily accessed from either the toolbar or the file menu.

REALVIZ® Stitcher® 3.1 Interface

The very simple interface and efficient workflow make creating panoramas extremely easy. The first step is of course taking you photos. The requirements of which are no different than any other stitching program. You simply take photographs with a 15%-30% overlap, ensuring that white balance and exposure are as close as possible in each photo.
The second step involves loading all of your images into the image strip window. Even with a few dozen 1 meg. images selected, they load very quickly into the program. Once loaded you have the option to set the resolution of the displayed images to adjust for display speed, and on-screen quality. If you are running on a slower machine with large images this is particularly useful. Stitcher® allows you to import pretty much any image type, including: Cineon, Maya, JPG, PNG, Portable Pixelmap, SGI, Softimage, TIFF, TGA and BMP.

Supported import file types

Once all of your images are imported you move on to step two, which involves stitching all of your images together. This process is amazingly fast and accurate. Although you have the option of entering in your camera's focal length settings, among others, REALVIZ® Stitcher® can do this for you by analyzing two or more stitched images. To stitch images, you simply drag from the image strip window to the stitching window. As each sequential image is dragged in, it appears slightly transparent so that you can roughly position it over previous image using the slight overlap of features as your guide. Once the image had been positioned, pressing enter lets the program do the hard work of analyzing the two images, at a pixel level, to precisely position and lock the image in place. This procedure is repeated until you have stitched all of you images together. The same process applies for creating full 360 or spherical panoramas.

Stitching process - Roughly align images then press enter to let Stitcher® do the rest.

The last step involves rendering out the stitched images to the desired format. REALVIZ® Stitcher supports the following output types: Planar projection, cubical projection, spherical projection, Cylindrical and Cubical QTVR projection, VRML and Shockwave 3D projection. REALVIZ® is unique in that they will allow you to author any size of panorama, limited only by the power of your desktop.
During the rendering process the program blends the images together and smoothes out any differences between adjacent images. During my tests there was a small amount of ghosting, but this was most likely the result of not using a panoramic head with my tripod. The parallax error, as a result, would have been compounded by the fact that the tests were done inside in relatively close proximity to the subject. Ghosting occurs when two adjacent images do no blend properly and identical elements from both images appear in the final render, slightly offset.
Unlike many of its competitors Stitcher allows users quite a bit of control over the QTVR projection exports. Users have full control over the CODEC, images output quality, Pan, Tilt, and POV settings as well as image size, to name just a few.
Another very note worthy aspect of the renderer is it's ability to render out projections in standard image formats so that they can be edited in an image editing program and later re-imported to render out the final projection, like a QTVR format.

QTVR Output setting dialog box

For users that find themselves taking the same type of panoramic images over and over again, using the same number of images and same camera settings, REALVIZ® has implemented a unique template system. Once a base panorama has been imported and stitched together you can save out a template. Using these templates users can automate subsequent image stitching sessions, allowing you to create your panoramas automatically.

With larger rendering jobs you can also use Stitcher's® Batch Command Prompt, which is a command-line version of Stitcher® that you can use to stitch, equalize, and render many projects at once. Most of the same options available to you in the GUI version can also be called in the command line version.

REALVIZ® Stitcher command line renderer/stitcher

CONCLUSION

From my tests I found REALVIZ® Stitcher® to be a top-notch application with excellent documentation and a very efficient and easy workflow. At $499US/561.00€, it is definitely at the top range of the panoramic software offering out there, but if you are looking for a no nonsense application that will get the work done and done right, then I think it should be put at the top your list of packages to seriously consider.
Although I didn't have too many complaints there were a few things that I think could have been improved. The first that comes to mind is the inability to easily preview FOV, Tilt and Pan settings. Although you can render out test renders, it would have been nice to be able interactively see how the panorama will be cropped or re-seized before you have to render out a QTVR format. I also found moving the images in the stitching window a bit confusing. Not because it is difficult but because the Ctrl, Alt and mouse click sequences were a bit counterintuitive to what most 3D packages use. The ability to set user shortcuts would be a nice touch in future releases. The last item I would have liked to see, is built in distortion correction for cameras with add on wide angle or fisheye lenses. Currently users must use third party image distortion programs to correct their images before import.
Overall though an excellent program worth a second look if you are in the market for panorama software.

REALVIZ® Stitcher® is available from REALVIZ® and is supported on Windows 98, ME, NT & 2000; MacOS 9.1x+. At the time of publishing REALVIZ® Stitcher® was selling for
$499US/561.00 €

Jeff Mottle is an architectural visualization artist currently working in Calgary, Alberta, Canada. He is the editor and owner of CGarchitect.com and is an active member in the architectural CG community. With just over five years of experience using Autodesk's Lightscape, Jeff has become one of the top Lightscape artists in North America.

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