Image compression based on tiled wavelet-like transform using edge and non-edge filters

摘要

An image processing system tiles an image data array. Each tile of image data is processed by applying a family of transform layers to the tile of image data so as to generate successive sets of transform coefficients. Each set of transform coefficients include edge coefficients positioned at outside boundaries of the set of transform coefficients and non-edge coefficients positioned at interior locations of the set of transform coefficients. The transform filters include a short edge transform filter that is applied to image data at boundaries of the tile and to coefficients positioned at and near boundaries of each of the earlier sets of transform coefficients so as to generate the edge coefficients, and a long interior filter that is applied to image data at interior locations of the tile and to coefficients at interior locations of the earlier sets of transform coefficients so as to generate the non-edge coefficients.