Vehicle detection through image processing for traffic surveillance and control

A method for operating programmable computing means to spatially process arrays of pixels representative of a field of view of traffic over time so as to generate data characteristic of presence of vehicles within the field of view, including:

• receiving successive sensed arrays of pixels representative of a field of view of traffic over time;
• time averaging corresponding pixels of successive sensed arrays over time to provide a time averaged array;
• summing corresponding pixels of the time averaged array with pixels of a sensed array to generate a background adjusted array;
• spatially averaging window groups of pixels of the background adjusted array to generate a spatially averaged array;
• generating a spatial variance array of pixels as a function of corresponding pixels from the background adjusted array and pixels from the spatially averaged array;
• and
• generating data representative of vehicle presence as a function of pixels of the spatial variance array.

A method for operating programmable computing means to temporally process arrays of pixels representative of a field of view of traffic over time so as to produce data characteristic of vehicle presence, including:

• receiving successive sensed arrays of pixels representative of a field of view of traffic over time;
• time averaging corresponding pixels of successive sensed arrays to produce a time averaged array;
• summing corresponding pixels of the time averaged array and pixels of a sensed array to produce a background adjusted array;
• generating a time variance array of time variance pixels as a function of corresponding pixels from a predetermined number of successive background adjusted arrays;
• and
• generating data representative of vehicle presence as a function of corresponding time variance pixels from the time variance array and background adjusted pixels from the background adjusted array.

A method for operating programmable computing means to process successive sensed arrays of pixels representative of a field of view of traffic over time to generate data representative of presence of vehicles within the field of view, including:

• independently spatially processing the arrays of pixels and generating spatially processed presence data representative of the presence of vehicles within the field of view;
• temporally processing the arrays of pixels independent from the spatial processing step and generating temporally processed presence data representative of the presence of vehicles within the field of view;
• and
• generating output data representative of presence of vehicles within the field of view as a function of the spatially processed presence data and the temporally processed presence data.

A vehicle detection system, including:

• means for sensing traffic in a field of view and for providing successive arrays of pixels representative of the field of view;
• means for controlling the selection of subarrays of pixels characteristic of changeable selected portions of the field of view from the arrays provided by the sensor means as a function of traffic within the field of view;
• and
• means for processing the selected subarrays of pixels and for providing data representative of presence and/or passage of vehicles within the selected portions of the field of view.

A method for determining information representative of the presence and/or passage of vehicles within a field of view, including:

• sensing a field of view of traffic and generating arrays of pixels characteristic of the field of view;
• controlling the selection of subarrays of pixels characteristic of changeable selected portions of the field of view from the generated arrays;
• and
• processing the selected subarrays of pixels and generating data representative of the presence and/or passage of vehicles within the selected portions of the field of view.