Creating virtual scenes using active contours and global motion estimation

This paper demonstrates how active contour segmentation and optical flow estimation techniques can be combined to create a seamless mosaic of frames from a video sequence. This virtual scene forms the basis of a number of post-production effects such as creating new image trajectories for the shot, or special effects which include new foreground elements. The optical flow method produces highly accurate global motion estimates by drawing upon an appropriate 3D geometrical model of camera motion. The active contour technique has been extended to include user selected edge data to guide crudely specified initial contours to their final location. The resultant rotoscoping tool dramatically improves the performance of traditional tools by using edge chain matching to relocate the active contour in subsequent frames