Edge preservative VQ based on the projection of images

The authors present an image compression scheme which has a good image quality based on vector quantization (VQ) of projections instead of the image itself and on simple postprocessing. The projection procedure makes it possible to transmit the edge preserving information. Usually the vector dimensions of projections are much smaller than that of the block, so it is possible to process a larger block in the projection domain than in the spatial domain with similar computational complexity. Processing large blocks can reduce the transmission bit rate by exploiting more interpixel correlation. As the block size increases, the blocking effect is more pronounced on background areas. To reduce this artifact, postprocessing is required. A multiorder polynomial interpolator for postprocessing the pixels was applied at and near the boundaries of background blocks. Simulation results show that the performance of the suggested scheme was superior to that of the normal VQ scheme