REALVIZ Stitcher

Product version: REALVIZ Stitcher v. 4.0

REALVIZ Stitcher's main screen consists of a "builder" panel in the top half, where you position images, and the "image strip" panel at the bottom. When you first load your images in they will appear as thumbnails in the image strip.

You do not need to tell REALVIZ Stitcher anything about the lens used because with full 360 degree panoramas it can work out the focal length when you align the last pair of images together. Even when you are stitching a non-360 degree arrangement of images, REALVIZ Stitcher can analyse the images to work out the best lens settings to achieve a good stitch.

Nevertheless, if you know the focal length or if you want to fix it, you can specify it. I found this useful to avoid completing the 360 degree sweep prematurely when aligning some of my images - if the focal length is too small it will seem as if there is insufficient space in the "builder" panel to fit in all your images.

Stitcher 4.0 also recognizes EXIF data in JPEG images (EXIF data is silently added to JPEG images taken with digital cameras). It can use this data to determine the focal length without asking you.

One by one you drag images onto the builder panel and align them together. After each image is positioned, you click stitch and REALVIZ Stitcher attempts to find a precise alignment - you need only position each image approximately. When you align an image with another a red line links the thumbnails in the mosaic panel. Once stitched the line becomes green.

After stitching the third image, Stitcher will automatically prompt you to estimate the focal length based on the supplied images.

If you have a lens that exhibits linear distortion, you can correct the distortion in Stitcher 4.0 (note the "distortion" parameter in the camera properties above). Stitcher can estimate the distortion characteristics if you run the high distortion calibration with just two images:

In my experiments, the high distortion correction capabilities should be enough to correct any rectilinear lens with slight linear distortion, but it cannot correct for a full frame fisheye (or at least not my Nikon FC-E8 fisheye in full frame mode).

Annoyingly Stitcher seems to get confused quite easily when trying to stitch images. Even though it seems to me that I have aligned the image quite well, Stitcher sometimes claimed it was unable to stitch the image for me. I'm hoping this is because the sets of images I used for this screenshot walkthough are old and were not shot all that well. REALVIZ say that this normally happens if there is insufficient detail for the stitch (e.g. you are stitching sections of blue sky in an outdoor spherical panorama). For these situations you can "force" the stitch.

Once you get to the final image in the set, you can use close panorama to align the first and last images together. REALVIZ Stitcher can then deduce the correct focal length and re-proportion and adjust the entire panorama.

When you render the panorama, Stitcher assumes that your current view is level with the horizon. To make it easy for you to level the stitched images, Stitcher 4.0 can automatically determine the horizon for a cylindrical panorama, and you can manually set the horizon by plotting vertical or horizontal vertices.

If your images differ in contrast, Stitcher can equalize them for you too

Stencil

Stitcher provides a quite sophisticated "stencil" tool to allow you to finely control the way images are blended together. This is intended to allow you to avoid problems of things moving in the panoramic sequence (e.g. cars driving past, people walking around etc). Having said that, the stencil tool also allows you to crop the image and correct for vignetting to some extent.

Here I have highlighted some people walking by and made sure they are included in the render. Back in the builder panel I can get stitcher to display the stencil too.

Hotspots

Stitcher 4.0 allows you to define hotspots too, by drawing polygons on the panorama and then defining what they do. Stitcher supports hotspots for QuickTime VR (cylindrical or cubic) and creates QuickTime files suitable for the web. You can specify the URL for a link, whether it is a QuickTime movie and whether to display the link in the viewer, or in what part of the web browser to display it.

Render

Stitcher supports a large number of image formats, QuickTime VR, Shockwave 3D and VRML. You can specify output size, check the rendering area, preview the output before rendering the full-size image, and specify compression parameters. Stitcher now supports multi-layer PhotoShop PSD format for rendering as well as various other formats.

When you specify QuickTime VR for output, you can control the compression codec, file size, rendering area (for cylindrical), meta data, preview functionality, initial view and viewer size, etc.

Once you have selected your output options, just click render.

Panorama Conversion

Stitcher makes it easy for you to post-edit your panoramas. The idea is that you can output your panorama as an image or series of images (e.g. cube faces) and then edit them in your preferred image editor. Once you're happy with your edits, you can use Stitcher to convert the edited images into a QuickTime VR movie, Shockwave 3D file, VRML object etc.

Template

If you tend to use the same camera/lens and technique for all your panoramas, templates are a great new feature you will find save you lots of time. Just stitch one set of images and then save the project as a template. You can then use the template to stitch similar sets of images shot with the same lens and in the same arrangement (i.e. the same number of pictures shot in the same number of rows). The catch is that the images really must be shot with exactly the same equipment, settings and in the same order and same way.

Batch jobs

A command line batch runner (now both on Windows amd Mac versions) allows you to tell Stitcher to do a task (or lots of tasks) without you being there. A simple example would be to ask Stitcher to stitch a panorama and create a QuickTime 5 cubic movie:

This means that you could stitch all your images and save the projects without doing the render and then use a batch script to have Stitcher do all the rendering afterwards. For large images the render may take a while, so you could use the batch script to get Stitcher to stitch in the evening or overnight while you do something else.

You can also combine the batch job functionality with templates. If you shoot all your panoramas with the same camera/lens and in the same way, you can use stBatch to get Stitcher to load the template, substitute the images, re-align and stitch all of them, equalize and then create a panorama for you, such as: