For example, we have developed fast algorithms for estimating camera motion directly from MPEG compressed video. When the camera motion satisfies certain constraints, then estimates of camera motion from the MPEG file are surprisingly accurate and can be used in suitable contexts as a useful indication of video content. We have also developed efficient algorithms for measuring the similarity of two video clips and for searching compressed video to find segments that are similar to a given example clip. A related area of research is the registration of images and video from multiple cameras. Once the frames of the videos have been adequately registered, they can be processed to create new views either for presentation or analysis purposes.
Image registration is an important step, for example, in tomography and medical imaging.
Registered video frames can be used to form a mosaic. This gives a compact representation of the video as well as a new way to visualize the data. Another application is the creation of the view from a new virtual camera located in a restricted region of space relative to the actual cameras. This requires the correspondence between the frames and the virtual view to be accurately determined so that the virtual view can be rendered from the given data. Another line of recent research is concerned with the stability and performance of switched adaptive algorithms for predication and control.