Patent ID: 7940961
Filing Date: 2011-05-10
Classification: G06T,G08B

Abstract:
1. A method for enhancing the detection of moving objects within a scene comprising the steps of: (a) providing a video image of said scene, wherein said video image is a new video image of said scene provided by a sensor which monitors said scene; (b) establishing a history of video images of said scene, wherein said history of video images of said scene includes a plurality of pixels of the moving objects and background within said scene; (c) computing an average pixel intensity and a variance for each of said plurality of pixels within said scene; (d) computing a difference in pixel intensity of the new video image of said scene from a historical average for said scene and then smoothing said difference to remove Gaussian noise from said scene, wherein a scene difference image is created which holds and provides a level of change in the pixel intensity present in each of said pixels for the new video image of said scene; (e) initializing a threshold level for said pixel intensity to a value which is a selected number of standard deviations; (f) extracting outlier pixels from said scene, wherein the pixel intensity of said outlier pixels exceeds the historical average by said threshold level times the standard deviation of said outlier pixel, said outlier pixels representing moving objects within said scene; (g) creating a binary image from said outlier pixels within said scene, wherein the binary image of said outlier pixels comprises bright moving objects or dark moving objects in said scene, or both bright moving objects and dark moving objects in said scene; (h) analyzing said binary image to count blobs present in said binary image, wherein each of said blobs in said binary image comprises a highlighted pixel grouping within said binary image; (i) creating a threshold adaptation curve which is used to generate a threshold adjustment curve, said threshold adaptation curve being created by a user based on a relative desire by said user for the number of said blobs to be detected within said scene, wherein said user sets a relative desire level for the number of said blobs to be detected in said scene; (j) adjusting said threshold level for a next new video image of said scene, wherein the number of said blobs found in said binary image are used as a feedback control to adjust the threshold level for processing of the next new video image of said scene acquired by said sensor; and (k) weighting said outlier pixels in said new video image of said scene based on a length of time that each of said pixels in said new video image has been one of said outlier pixel.