Low-bit-rate video coding using a planar representation with multiframe maps.

The “layered representation” is a method to represent a moving image by relatively moving layered maps in each divided region after they have been superimposed in image depth order, like cell images in an animated picture. The conventional layered-representation coding method can efficiently represent an object with small movements, such as a background, but the method has difficulty in representing a nonrigid object which changes its texture and shape, like an image of a person. This paper describes a layered-representation coding method which overcomes this difficulty. The proposed method divides each region along the time axis, and a moving image including nonrigid objects is efficiently reconstructed by mixing maps of frames. This paper also describes an expanded setting representation which can treat three-dimensional data efficiently. The proposed method can represent a smooth moving image without discontinuous frame shifting, since its image quality can be controlled spatially and temporally. The proposed method is compared with a conventional method (waveform-similarity method H.263) of a low-bit rate (less than 32 kbit/s), the former being superior to the latter in a visual evaluation. © 1999 Scripta Technica, Syst Comp Jpn, 30(1): 70–80, 1999 [ABSTRACT FROM AUTHOR]