Three-source boundary interpolation image coder

Two-source decomposition image coders consist of coding algorithms in which a boundary-based interpolation is subtracted from each block of the image to obtain a residual signal that is encoded and transmitted. These coders effectively reduce the objectionable blocking distortion that often accompanies block-by-block coding strategies and, for this reason, are becoming an attractive alternative to traditional transform coders in low bit-rate applications. The authors enhance the appeal of this approach by introducing a three-source decomposition scheme that increases the fidelity of the boundary response or, equivalently, decreases the informational content of the residual. This decomposition permits the development of an interpolative coder capable of producing perceptually good quality images at low bit rates without the disturbing blocking effect