Patent ID: 6094225
Filing Date: 2000-07-25
Classification: H04N

Abstract:
A method for encoding mode signals of a target block of a binary shape signal, wherein the binary shape signal includes a plurality of pictures, each picture is divided into a multiplicity of blocks of M.times.N pixels having one of a first and a second binary values and the target block is encoded by either a frame-based coding to be encoded on an M.times.N pixels basis or a field-based coding to be encoded on an M/2.times.N pixels basis, the target block representing one of the blocks of a current picture to be encoded and M and N being positive even integers, respectively, comprising the steps of:(a) generating a first indication signal, if error of the target block with respect to a first reference block is not greater than a predetermined threshold, and generating a second indication signal, if error of the target block with respect to a second reference block is not greater than the predetermined threshold, the respective reference blocks having M.times.N pixels and all pixels of the first and the second reference blocks being of the first and the second binary values, respectively;(b) if none of the first and the second indication signals are generated in step (a), selecting either the frame-based coding or the field-based coding to generate a coding mode signal, wherein the coding mode signal indicates whether the target block is encoded by using either the frame-based coding or the field-based coding;(c) generating a base mode of the target block based on the first and the second indication signals and the coding mode signal;(d) if the frame-based coding is selected in step (b), coding the target block by the frame-based coding to generate a frame mode and frame-coded data, wherein the frame mode represents a coding condition of the frame-coded data;(e) if the field-based coding is selected in step (b), coding the target block by the field-based coding to generate a field mode and field coded data; and(f) combining the base mode and the frame mode or the field mode to generate a mode signal for transmission of the target block.