Patent Document ID: 20100067741
Application ID: 12317317
Patent Status: 0

Claim One:
1. A method for tracking the image position of a tracked object that appears in a plurality of successive frames of an image sequence, said method comprising the following steps: a) Initializing the method by identifying a target region (a region of a frame in the image sequence representing the object to be tracked) in one given frame of said image sequences, b) Developing a characterization of the tracked object pixels, c) Defining a search window, said search window comprising a designated region of the image which is to be searched for the tracked object, said search window to have an area r times greater than the area estimated for the target region identified in step a), d) Centering said search window on the centroid of the target region identified in step a), e) Positioning the search window at an initial location in a successive frame of the image sequence, f) Developing a characterization of said search window's pixels at said search window's present location in the present image in the sequence, g) Computing, for each pixel in the search window, the probability that the said pixel represents, the tracked object; said computation making use of numerical image data associated with said pixel, said characterization of said tracked object pixels developed in step b), said characterization of said search window pixels developed in step f), and the Bayes law equation (1), said pixel probabilities thereby forming a two dimensional distribution of the tracked object's location in the image, h) Estimating the new object location as the centroid of said two dimensional distribution calculated in step g), i) Repositioning said search window to be centered on said new object location as determined in step h), j) Iteratively repeating steps f), g), h), i) until the position of said search window converges, said convergence meaning that the difference between the positions, calculated for said search window in step i) of two consecutive said iterations, falls below a threshold value, k) Repeating the steps e), f),g), h), i) for each successive frame of said image sequence.