# The PanoramIX Authoring Tool

## Version 0.1.4.92, February 26, 1998

## 5. The Options Menu

Functions and dialogs are provided for controlling or selecting the following options:

1. Panorama Wizard
2. Camera Properties
3. Blended Panoramas
4. Exposure Balancing
5. Automatic Alignment
6. Activating Sprites
7. Hot Spot Preview

## 5.1 The Panorama Wizard

A preliminary trial version of the Panorama Wizard can br selected from the Options Menu. This wizard prompts users for answers to the following four questions:

1. Is this a new panorama, or are we going to re-open a previously created panorama?

2. If this is a new panorama, are the images based on digitized photographs, or are they composed of computer generated images?

   In this case, "computer generated images" means digital images produced by a 3d rendering application based on a 3d digital model. Such images may be produced by applications such as PhotoRealistic RenderMan, 3d Studio Max, Lightwave, Alias, WaveFront, Caligari TrueSpace, and many other 3d rendering applications.

3. If the images are based on digital photographs, are they based on flat photographs or a panoramic image.

   A "flat photograph" is the type of photograph produced by a conventional camera. A panoramic image may be created by a specialized panoramic camera which can capture a full 360 degree image in a single image.

4. Does the scene include a top image, a bottom image, or any sprites?

After answering these four questions, the user is presented with appropriate dialogs needed to identify the camera properties and the control file or image files needed to compose the panorama.

Back to the Options Menu

Back to PanoramIX Authoring Tool

## 5.3 Blended Panoramas

The panorama editor can combine a set of images into a panorama using either of two methods. In the first method, each image is trimmed to the left, right, top, and bottom. Adjacent images are warped to a cylinder and positioned side-by-side as if cut with scissors. top and bottom images fill the areas above and below the areas covered by the side images, giving priority to the side images where there is any overlap. Each pixel in the resulting panorama comes from only one of the original images. Each of the trimmed images may be saved individually and the resulting panorama may be reconstructed by the browser or plug-in after reading all of the files for the sides, top and bottom.

One problem with this cut and paste approach to building a panorama is that the boundaries where adjacent images meet may remain noticeable do to exposure variations or other imperfections in the images.

As alternative to trimming the images to eliminate the overlapping areas of adjacent images, it is also possible to blend the overlapping areas together to provide a smooth and continuous transition from each image to the next. In principle, the overlapping areas contain equivalent and redundant information. If the images are correctly aligned, any details in one image will coincide with the same details in any overlapping area of another image. This method can be enabled by selecting the Blend entry in the Options menu. Selecting this again disables this mode and returns to the trim and join method.

Blending adjacent images can provide a good way to smooth over exposure variations and to produce a seamless panorama, but it is not a substitute for getting the images aligned. If anything, accurate image alignment is even more critical for blended panoramas than for non-blended panoramas. If adjacent images are not perfectly aligned, the resulting blended panorama will show ghosts of features from one image near the same feature from the second image. If something moves between capturing one image and the capture of an adjacent image, then this will appear as a ghost in the blended panorama.

The amount of area that is actually blended when two or more images overlap is controlled by the cropping boundaries that can be set in the image editing dialogs. This region can be made to be relatively small to minimize the problems caused by moving objects and alignment difficulties.

Blended panoramas can be saved only by selecting the Save Panorama entry in the File menu. A blended panorama cannot be saved as a set of trimmed images using the Save Sides entry in the File menu.

### Anti-Ghosting Functions

If the scene contains people, animals, vehicular traffic, or any other moveable items, it is likely that these items will move between the times at which the various pictures are taken. If this happens, one may find a person or some item is visible in one photograph, but not in the overlapping portion of an adjacent photograph. In some cases, the person or object may be visible in both images, but not in exactly the same position or orientation. When these images are blended to form a panorama, one finds ghost-like images of the moving item(s) in the blended panorama. There are several techniques which may be used to suppress the ghosts of moving items. For example, one may use image processing operations to remove the object from the scene. In addition, the panoramix authoring tool has some built-in anti-ghosting functions. These functions are controlled by the cropping boundaries. These boundaries are controlled from the Edit Sides, Edit Top, Edit Bottom, and Edit Panorama dialogs. The cropping boundaries for side images, top images, bottom images, and panoramic images can also be controlled and visualized in the Image Edit window.

Back to the Options Menu

Back to PanoramIX Authoring Tool

## 5.6 Activating Sprites

A panorama may contain sprite images as well as top, bottom, and side or panoramic background images. The sprites may be specified in a Raw Image Control File, or they may be imported directly through the Import Images entry in the File menu. By default, the sprites are inactive and invisible, but they can be activated at any time by selecting the Activate Sprites entry in the Options menu.

Back to the Options Menu

Back to PanoramIX Authoring Tool

## 5.7 Showing Hot Spot Areas

The locations of any hot spots may be determined by selecting the Show Hot Spots entry in the Options menu. When this is selected, the colors of pixels associated with hot spots are altered so as to reveal the locations of the hot spots. The resulting colors are arbitrary and serve only to reveal the locations of hot spots. Selecting this again restores all of the normal colors.

Back to the Options Menu

Back to PanoramIX Authoring Tool

Last modified February 27, 1998.
wluken@watson.ibm.com