1. A computer implemented method of rendering an integrated image constituted of a computer generated three dimensional scene and a base image, the method comprising: providing the base image; displaying said base image; providing the computer generated three dimensional scene; rendering said provided computer generated three dimensional scene responsive to a determined camera calibration of said displayed base image as an overlay over said displayed base image; displaying the base image additionally in the foreground of said rendered three dimensional scene at a predetermined transparency; identifying elements from said additionally displayed base image to appear in the foreground of the integrated image; displaying said identified elements of said additionally displayed base image without transparency; and removing all unidentified elements of said additionally displayed base image thereby rendering said integrated image.