Patent ID: 7418113

Claim:
A method for tracking a moving object in a video acquired of a scene with a camera, comprising the steps of: acquiring a video of a scene, the video including a sequence of frames, each frame including a plurality of pixels, and for each frame, further comprising the steps of: maintaining a background model; detecting a moving object according to the background model; maintaining an object model for the moving object, in which the object model is a (W×H)×D matrix of elements, each element including color samples, where W and H are a width and height of the object model respectively, and D is a depth measured in terms of successive frames; assigning, to the moving object, a plurality of kernels according to a likelihood of a pathway of the moving object and a likelihood of the object model; applying, to each kernel, a mean-shift process to estimate a location of the kernel, in which the estimated location of the moving object in a current frame is z 1 , and pixels inside the object kernel are (x i , u i ) N i=1 , where x i is a 2D coordinate in a frame coordinate system and u i is a feature vector including color and perpendicular gradient magnitudes of pixels, and sample points in the object model are represented as (y j , v jk ) M j=1 , where y j are the 2D coordinates in an object model coordinate system and v jk is a feature vector {v jk } k=1, . . . , D+2 for 2D colors and gradient magnitudes; combining the estimated locations of the plurality of kernels; and determining an estimated location of the moving object according to the combined estimated locations of the plurality of shift kernels to track the moving object in the video.