An edge-oriented progressive image coding

An edge-oriented progressive image coding scheme using a hierarchical edge extraction is presented. This scheme is based on the two-component model, that is, edges and smooth component. We introduce searching near an approximate location algorithm for the edge extraction to avoid detecting spurious edges, thus, one can reproduce a primary image which conveys a general grasp of the scene while achieving the compression ratios as high as 250:1 for a head-and-shoulder image. By adding the smooth component to the primary image, we obtain acceptable quality images at the compression ratios over 60:1. It is shown through the simulations that the proposed scheme results in performance improvements over MPEG-2 I-picture coding in terms of both the subjective quality and signal-to-noise ratio. The main contributors of the performance improvement are: (1) a compact representation of the edge information using a hierarchical edge extraction and (2) a residual coding with a variable block size discrete cosine transform (DCT) employing an edge-based block segmentation.