A Recent Innovation in Digital Special Effects: The CBS “Action Track”^TM System

The CBS Action Track system generates real-time multiple-image video of objects in motion using any normal color video source, live or prerecorded. Requiring neither special lighting nor special backgrounds, the system produces video depicting not only the present image of a moving object but also a selectable succession of earlier images commencing with a particular action. Utilizing the advantages of PCM-encoded video and digital random-access memory, Action Track obtains the intended effects: (1) by storing a reference field of video representing the scene at the start of the desired action; (2) by comparing picture elements of subsequently arriving video with those of the reference field; (3) by tagging and storing those pixels visibly different from those in the reference field; and (4) by displaying the real-time video with the substitution of those tagged and stored pixels which comprise the successive images of moving objects. Within the constraints of the television system itself and by utilizing controllable picture gating, Action Track has been successfully and effectively used in a variety of sports telecasts. For these applications it has provided the viewer with expanded visualization of motion and trajectory.

Print ISSN

0036-1682

Published

1978-10

Content type

Original Research

DOI

10.5594/J16656