Abstract: A method for reconstructing an incomplete signal in a sub-band transmission system is disclosed. Signal degradation from signal loss in a sub-band transmission system may be avoided by formulating an error function, and finding an optimal signal which minimizes the error between the sub-band signals interpolated from received sub-band signals and the sub-band signals obtained by convolving an optimal reconstructed signal with the original analysis filters. The minimized system equation is solved to provide an optimal reconstructed output signal.

Abstract: A system for enhancing the quality of an image that suffers from staircase effects, contouring effects, and granular noise, without affecting the existing method of creating the image is disclosed. The enhancement system identifies the edge and nonedge regions in the decoded image, and then filters those regions in order to reduce the specific type of quality degradation that generally occurs in the specific type of region. The system is integrated into a processing system including means for receiving and displaying digital image data. The system receives the digital image data, differentiates between edge data and the nonedge data within the digital image data, and filters the image data accordingly. The filtered edge data and the filtered nonedge data are combined to form an enhanced image. A multi-pass filtering system is also disclosed.