Shows that, provided an error-correcting source decoder is used, a higher quality of transmitted image can be achieved by applying a weaker channel code and hence transmitting more source data (finer quantization) in the same bandwidth.

This paper presents an a posteriori channel error correction method, based on subband synthesis. We estimate the position and amplitude of transmission errors using undownsampled subband signals, thus allowing correction of the subband signals and resynthesis of a nearly error-free signal. The method can be extended to multiple dimensions. Examples of images transmitted (compressed) with and without this method are shown. The results are very promising.

An image sequence coding scheme for very low bit-rate coding is presented. The scheme is based on spatial redundancy reduction via the new edge-sensitive subband coding method and temporal redundancy reduction via windowed overlapped block-matching motion compensation. In this scheme, only significant regions of difference images are coded. Thus, the computational cost can be kept low. Significant regions are considered to be regions where motion is present (temporal activity) and/or regions where the image is very detailed (spatial activity). The significant regions are determined by an adaptive strategy based on both the motion vectors and an edge map of the current image. The scheme has the main advantage that there are no blocking effects in the decoded images at all due to the properties of both the temporal and the spatial coding used. The overall visual performance of the coding scheme is very good.

In this paper, we introduce a family of novel edge preserving image coding techniques based on the discrete wavelet transform (DWT). These techniques utilize the edge map (which not necessarily contains closed curves) of the processed image or its subbands in the way that no filtering over edges is performed. This results in a reduction of power in the higher frequency bands. The achievable savings are higher than the additional bit rate needed for transmission of the edge map.

In this paper we present an image sequence coding scheme for very low bit rate coding which is based on spatial redundancy reduction via the new edge sensitive subband coding method and temporal redundancy reduction via windowed overlapped block-matching motion compensation. The scheme has the main advantage, that only the significant regions of difference-images are coded. Thus the computational cost can be kept low. Due to the properties of both the temporal and the spatial coding used, there are no blocking effects in the coded images, and the overall visual performance of the coding scheme is very good.