Patent ID: 6477279
Filing Date: 2002-11-05
Classification: G06T,H04N

Abstract:
A system for encoding and decoding a digitized image consisting of pixels having pixel values, comprising:an input terminal for receiving said digitized image; a series of smoothing filters coupled to said input terminal, having progressively lower cut-off frequencies, for filtering said digitized image to generate a series of filtered images culminating in a low-frequency image, which was filtered with a lowest cut-off frequency among said cut-off frequencies; a down sampler coupled to a last one of said smoothing filters in said series, for down-sampling said low-frequency image to generate a reduced image; means for generating an edge image by detecting edge points in one image among said digitized image and said filtered images, excluding said low-frequency image; an encoding section coupled to said means for generating an edge image and said down sampler, for encoding said edge image, thereby obtaining edge information, and encoding said reduced image, thereby obtaining low-frequency information; a decoding section for decoding said edge information to generate a pair of edge images, comprising a horizontal edge image and a vertical edge image, and decoding said low-frequency information to regenerate said reduced image; an up sampler, coupled to said decoding section, for up-sampling said reduced image to generate a decoded low-frequency image equal in size to said edge images; a plurality of edge synthesizers, each coupled to said edge information decoder having respective edge synthesis filters, for synthesizing a series of pairs of high-frequency images by filtering said horizontal edge image horizontally and said vertical edge image vertically with said edge synthesis filters; an inverse wavelet transform processor, coupled to said up sampler and said plurality of edge synthesizers, for performing an inverse wavelet transform on said decoded low-frequency image and said series of pairs of high-frequency images; and means for transmitting said edge information and said low-frequency information from said encoding section to said decoding section.