Image processing system

An image processing system comprising a template matching engine (TME) operatively connected to a memory storing image information, the TME being configured to:

• read at least a portion of an image from said memory using a raster scan;
• and
• as each pixel of said image portion is being read, calculate a respective feature value of at least three feature maps as a function of said pixel value;
• the TME comprising:
• a classifier arranged to apply at least one detector cascade to a window within a portion of an image in order to indicate if said window comprises an object to be detected, one of said at least one detector cascades comprising a multi-stage random tree classifier (RTC), each stage comprising a decision tree having at least three nodes corresponding to respective pixel locations within said window, said classifier being arranged to compare a feature value from a selected one of said plurality of feature maps corresponding to a pixel location to a threshold value for each of said nodes of said detector cascade, wherein training of said detector cascade is restricted so that selected feature maps for each node of a stage are each different, said classifier being arranged to simultaneously read feature values for each node of a stage from said feature maps and to simultaneously compare each of said feature map values to respective thresholds to determine a score for a stage, and said classifier being arranged to compare an accumulated score for a window after each stage with a stage threshold to determine whether or not to continue with a next stage of said detector cascade.

An image processing system comprising a template matching engine (TME) operatively connected to a memory storing image information, the TME being configured to:

• read at least a portion of an image from said memory using a raster scan;
• and
• as each pixel of said image portion is being read, calculate a respective feature value of a plurality of feature maps as a function of said pixel value;
• the TME comprising:
• a classifier arranged to apply at least one multi-stage detector cascade to a window within a portion of an image in order to indicate if said window comprises an object to be detected, said classifier being arranged to compare an accumulated score for a window after each stage with a stage threshold to determine whether or not to continue with a next stage of said detector cascade;
• and
• a programmable controller, said controller being arranged to provide said classifier with a plurality of limited stage detector cascades to be successively applied to a window, the programmable controller being arranged to receive a respective accumulated score for each limited stage detector cascade from said classifier and to apply rules from a rules engine to determine which of a plurality of longer detector cascades corresponding to said limited stage detector cascades are to be applied to said window to enable said classifier to indicate if said window comprises an object to be detected.