1. A system for automatically identifying a boundary curve for delimiting an object of interest within an image frame, comprising using a computing device to perform the steps for: receiving an image frame containing an object of interest; sampling separate areas of the image frame to initialize separate probabilistic color distribution models of a foreground region and a background region of the image frame, said probabilistic models of the foreground and background regions jointly comprising a local image data likelihood; initializing a global image data likelihood as a function of a combination of the probabilistic models of the foreground and background regions of the image frame; initializing a boundary curve as a boundary surrounding the area of the image frames sampled to initialize the probabilistic model of the foreground region; and jointly performing an iterative minimization of energy functionals representing the boundary curve, the local image data likelihood and the global image data likelihood to generate a final boundary curve for delimiting the object of interest.