Image coding and decoding method, e.g. for digital transmission over communications network, selectively using two coding modes, each optimizing the compression of an image as a function of different optimization criteria

摘要

Information on the choice of an image coding mode is known from a decoder according to at least one of : (1) a predefined choice known to the coding and decoding units; (2) information relating to the choice included in a data stream including at least some of the coded images; (3) information relating to the choice included in a data stream and independent of the coded images; and (4) determination in an intrinsic manner by the decoder. Preferably the first coding mode involves transformation and time prediction on image blocks and may especially involve MPEG-4 coding, while the second coding involves a mesh operation, the mesh preferably being of triangular form. Independent claims are included for : (1) an image coding device; (2) an image decoding device; (3) an image storage device; (4) an image coding and/or decoding system; (5) a computer program product for image coding and decoding; (6) an image data signal; and (7) application of the image coding method to: (a) digital television; (b) real-time video transmission over an IP network; (c) real-time video transmission over a mobile network; and (d) the storage of image data.