A segmentation-based predictive multiresolution image coder
Recursive rectilinear tessellations like quadtree are widely used in image coding, but a regular tessellation, despite simple geometry, may not suit image compression because it is too rigid to reflect the scene structure of an image. The paper presents a new image pyramid formed by adaptive, tree-structured segmentation to be a framework of a predictive multiresolution image coder. Subjectively appealing compression results are obtained at different resolutions by scene-adaptive, tree-structured segmentation and by exploiting the statistical dependency between the layers of the image pyramid. The adaptive segmentation-based image coder is constructed by recursive, least-squares piecewise functional approximation. The seemingly expensive encoding process can be made efficient by an incremental least-squares computation technique. The decoding is simple and can be done in real time if assisted by existing hardware technology.