Tracking (image)

Following a defined point, or points, in the pictures of a clip. Initially this was performed by hand, using a DVE but was laborious, difficult and limited to only to pixel accuracy. Now image tracking is widely used, thanks to the availability of automatic point tracking operating to sub-pixel accuracy. The tracking data can be applied to control DVE picture moving for such applications as the removal of film weave, replacing 3D objects in moving video, wire removal, etc.

Advanced multiple point tracking is sometimes used to analyze images in 3D, so allowing a whole raft of computer-generated material to be move-matched for compositing into live scenes, blurring the boundaries of live and synthetic imagery.

See also: Corner pinning, Sub-pixel