Composite image generation with hidden surface removal using a single special effect generator

Abstract

A method of generating an output video signal includes processing two or more input digital video signals so as to manipulate images that they represent and combining the processed signals to form the output video signal, which represents a composite image in which the manipulated images appear to fly through one another. In a first pass, a digital video effect generator (1) is supplied (4) with one of input video signals and is responsive to data (5) representing at least the manipulation to which the image represented by that one input signal is to be subjected to process that one input signal to subject the image represented thereby to the manipulation intended for that image. The processed signal resulting from the first pass is recorded (VTR1). In at least one subsequent pass, the generator 1) is supplied with the other or another of the input video signals and is responsive to data representing the manipulations to which the images represented by all of the input signals are to be subjected to process the other input signal so as to subject the image represented thereby to the manipulation intended for that image so as to crop or remove from the manipulated image any one or more portions thereof to be hidden in the composite image. The processed signal resulting from the at least one subsequent pass is keyed (16) into the recorded signal resulting from the previous pass.

Dependencies are inferred from the claim text.