RECOMMENDED DEPTH VALUE FOR OVERLAYING A GRAPHICS OBJECT ON THREE-DIMENSIONAL VIDEO

摘要

A method of generating a recommended depth value for use in displaying a graphics item over a three dimensional video is described. The method includes at a headend: receiving a three dimensional video including video frames; analyzing a sequence of said video frames in turn to produce a sequence of depth maps, each depth map in the sequence of depth maps being associated with timing data relating that depth map to a corresponding video frame in the sequence of video frames, each depth map including depth values, each depth value representing a depth of a pixel location in its corresponding video frame; selecting a region of depth maps in the sequence of depth maps; analyzing said region of the depth maps in the sequence of depth maps to identify a furthest forward depth value for said region in the sequence of depth maps; and transmitting the furthest forward depth value as the recommended depth value for the region to a display device and region information describing the region.