CODING OF SIGNIFICANCE MAPS AND TRANSFORM COEFFICIENT BLOCKS

摘要

For the associated positions within the transform coefficient block, successively extracted syntax elements indicating whether a valid or invalid transform coefficient is located at each position are at the positions of the valid transform coefficients previously indicated by the associated syntax elements. Between the positions of the transform coefficient block determined accordingly, a higher coding efficiency is achieved for the validity map coding indicating the positions of the effective transform coefficients in the transform coefficient block by a scan order that is successively associated with the positions of the transform coefficient block. do. Alternatively, elements of the first type are adapted to the context using contexts individually selected for each of the syntax elements according to the number of adjacent effective transform coefficients of each syntax element, marked as valid by any previous syntax elements. It can be entropy decoded alternatively. Also alternatively, values are scanned in the subblocks and a context is selected based on the subblock statistics.