Patent ID: 6724915
Filing Date: 2004-04-20
Classification: G06T

Abstract:
A method for tracking a video object in a time-ordered sequence of image frames, comprising the steps of:(a) identifying an object to be tracked in said time-ordered sequence of frames; (b) selecting starting and ending frames for said object; (c) marking a boundary of said object in said starting and ending frames; (d) defining and determining a shape, a marker, and a location for said object; (e) computing a model histogram for said object from colors associated with said object within said boundary; (f) tracking said object's shape, marker and location in a subset of frames in between said starting and ending frames; (g) using linear interpolation to find a corresponding marker and location for said object for frames in between the starting and ending frames and in which said object is not tracked; wherein the step (f) comprises: selecting frames in which said object is to be tracked; selecting two reference frames for a frame being processed from frames already processed based on their distances in time to said frame being processed and their confidence to said frame being processed; making a first predication of the location and marker of said object and a confidence level of tracking in said frame being processed from those for said reference frames; selecting from templates for said reference frames a references template for pattern matching; identifying a second prediction of the location and marker of said object by back-projecting said model histogram into said current frame and fusing said two marker and frame predictions based on spatial relations to find a search space to look for said object in said frame being processed; identifying the marker of the object in the frame being processed by matching said reference template to colors in said frame being processed; updating the confidence level of the tracking in the frame being processed; and finding the shape and location of the object in the frame being processed using histogram back-projection.