Model-based edge reconstruction for low bit-rate wavelet-based image coding

Low bit-rate image coding brings about an obvious degradation to the compressed images, among which, the distortions at the edges are particular objectionable. A model-based edge reconstruction algorithm is proposed for wavelet-based image coding at low bit-rate. Our approach applies a general model to represent the variety of edges existing in an image. Based on this model, the problem of edge reconstruction is formulated as finding the original edge model parameters from the lossy image. The proposed method is able to improve the subjective visual quality and fidelity (PSNR) of images coded by wavelet-based coding using zerotree quantization.