Patent ID: 8538072

Claim:
A computer-implemented method for detecting an operator's use of a secure system, the method comprising: acquiring one or more images from one or more image sensors, the image sensors being co-located with the secure system and monitoring a detection zone about the secure system; identifying one or more faces within the images; tracking the faces among subsequently acquired images; and upon receipt of a valid login at the secure system, (i) selecting one of the tracked faces as a primary operator, (ii) tracking the head of the primary operator independent of the primary operator's face in images obtained by the one or more image sensors during operation of the secure system, and (iii) determining movements of the primary operator based on at least one of a location or a size of the tracked head regardless of whether the operator is facing the one or more image sensors, wherein tracking the head of the primary operator independent of the primary operator's face comprises: assigning tracking points to points on tracked head images; periodically updating and re-assigning the tracking points; detecting errant points based on a velocity threshold; and applying a correction factor to the errant points, wherein the correction factor is based at least in part on an average change in position of neighboring points.