US Patent 7075556 Telestrator system

A telestrator system is disclosed that allows a broadcaster to annotate video during or after an event. For example, while televising a sporting event, an announcer (or other user) can use the present invention to draw over the video of the event to highlight one or more actions, features, etc. In one embodiment, when the announcer draws over the video, it appears that the announcer is drawing on the field or location of the event. Such an appearance can be performed by mapping the pixels location from the user's drawing to three dimensional locations at the event. Other embodiments include drawing on the video without obscuring persons and/or other specified objects, and/or smoothing the drawings in real time.