Introduction
The purpose of this project is to develop a camera system able to take stereo panoramic images in one shot.The simplest system for creating and viewing stereo images on a computer screen is with anaglyphs. Anaglyphs are two superimposed images of complimentary colours, that represent slightly differing angular viewpoints of the same subject. When viewed through bi-coloured glasses, the viewer sees a single combined three-dimensional image. This is the only stereo system that can be used in conjunction with the program QuickTime.
Bowl Camera
The first system devised uses a reflective half sphere to capture a distorted view of the world around it and then the captured image is digitised and stretched into a panoramic view. To produce stereo images two pictures have to be taken simultaneously from different viewpoints. Horizontal separation of the viewpoints would not allow a stereo view all around and would show the other camera in the view. Vertical separation works, but human eyes are arranged horizontally and the stereo effect only comes out with the viewer's head turned on its side, literally causing a pain in the neck. Vertically separated image pairs were taken to demonstrate the principle, using two shots.After the images have been exposed and the sheets of film processed the images are digitised with a scanner and then stretched with 'Stretch V2.02'. If the images are a stereo pair the two digitised images are first combined into an anaglyph image, using Adobe Photoshop, and then stretched. This creates an accurately stretched anaglyph image. Finally the image is prepared for conversion into a 'QuickTime' image using Apple's 'QTVR Make Panorama 2'.
An attempt was made to develop software to recognise objects and locate objects in the pictures and re-arrange them horizontally for viewer convenience. Difficulties automatically recognising object order and distinguishing between objects which are flat and those which span a range of distances caused this attempt to be abandoned.
Panoscancam
After coming to the end of the road with the development of the bowl camera due to the problems of converting vertically separated image pairs into horizontally separated pairs, another approach to the one shot system was taken. An electronic scanning camera was constructed from an ordinary sheetfed scanner. With the scanner line sensor vertically in the back of a camera and the scanner motor spinning the camera around, the sensor scans columns of a panoramic image. For stereo effect, the top half of the sensor is used for the left image and the bottom half for the right, each with their own lens. To create the left and right displacement, mirrors are used in periscope arrangements (much like in a submarine) in front of the lenses to give two separated views of the scene. This truly is a one shot system, but the imaging time is in the order of 30 seconds for the camera to make a full revolution.Postprocessing of the images consists of a simple series of Adobe Photoshop actions for anaglyph combination, and conversion to 'QuickTime' similar to that used for the bowl camera images.
Several stereo images have been taken to demonstrate the camera principles. Currently the system only works in monochrome and has no exposure control, but the results look promising and further development may be undertaken depending on funding.