Arrangement for, and method of, detecting motion of a target in a venue having multiple regions
An array of light sensors arranged along mutually orthogonal sensor rows and sensor columns is exposed to return light from a target over successive frames. The array is subdivided into mutually orthogonal zones, each having a sub-plurality of sensor rows and sensor columns. Each row of zones is scanned multiple times to produce output light intensity values, which are averaged to obtain an average zonal value for each zone for each frame. The average zonal value over the successive frames is simultaneously averaged with slow and fast response characteristics to obtain respective slow and fast response values for each zone, which are then compared to obtain a difference value for each zone. Motion of the target in any region of a venue is indicated when the difference value between the fast and slow response values in a corresponding zone exceeds a threshold value.