Patent ID: 6937760
Filing Date: 2005-08-30
Classification: G06T

Abstract:
1. A method for segmenting an object within a current digital image frame, comprising the steps of: receiving a set of control points used in deriving an object boundary from a prior image frame, wherein the received set of control points serves as an initial set of control points for the current digital image frame; defining a restricted area within the current digital image frame based on the received set of control points, wherein the restricted area corresponds to a band about the object boundary; updating the initial set of control points to an updated set of control points in response to an operator command; deriving a current frame object boundary as a closed contour connecting each control point of the updated set of control points, wherein only image data within the restricted area are eligible to form the closed contour, wherein the step of deriving comprises for each one control point of the updated set of control points deriving a path from said each one control point to an adjacent control point, wherein the step of deriving a path comprises: determining a distance from said one control point to said adjacent control point; when said distance is less than a threshold distance applying a first set of rules for deriving the path from said one control point to the adjacent control point, wherein the step of applying the first set of rules for deriving the path comprises applying a forward marching approach for determining the path, wherein said path occurs entirely within the restricted area; and when said distance is greater than the threshold distance applying a second set of rules, different from the first set of rules, for deriving the path from said one control point to the adjacent control point, wherein the step of applying the second set of rules for deriving the path comprises applying an outward marching approach, wherein said path occurs entirely within the restricted area; wherein said derived closed contour serves as a current frame object boundary.