Abstract: The present invention relates to a method of encoding blocks of values, e.g. DCT blocks, generated in accordance with an image compression scheme. The values are expressed as a set of bit planes, each bit plane comprising, for the values, all bits with a specific significance. In each bit plane at least one parameter is determined (7) in accordance with a predetermined definition, the parameter defining a partition of the bits in the bit plane which encloses all set bits. All bits in the partition are transferred (8) to a bit stream that may be truncated. This provides a method with low complexity. The invention further relates to a corresponding encoding device, a corresponding decoding device, and a corresponding bit-stream.

Abstract: The electronic device comprises electronic circuitry which functionally comprises a boundary detector, an analyzer and an includer. The boundary detector is operative to determine a boundary (47) between a relevant area (45) and an irrelevant area (43) of an image (41). The analyzer is operative to analyze blocks (55) of pixels intersected by the boundary (47). The includer is operative to include blocks (55) of pixels intersected by the boundary (47) in the relevant area (45) in dependence upon the analysis. The invention further relates to a method of determining a relevant area of an image for block-based image processing. The method comprises the steps of determining a boundary between a relevant and an irrelevant area of an image, analyzing blocks of pixels intersected by the boundary and including blocks of pixels intersected by the boundary in the relevant area in dependence upon the analysis.