ENCODER/DECODER AND ENCODING/DECODING METHOD

摘要

PROBLEM TO BE SOLVED: To eliminate information loss and to improve encoding/decoding efficiency by comparing a predictive value and an encoding object picture element and encoding the comparison result based on context. SOLUTION: An encoding control means 4 allowes an encoding image storage means 1 to store encoding object picture elements and output the reference picture elements in the vicinity or in the neighborhood. Next, the control means 4 outputs the binary signal of the encoding object picture element inputted in the same way from the predictive value predicted based on the reference picture element outputted from the storage means 1 of an adaptive predictive conversion means 2. A conversion means 2 allowes a context generation means 2b to start the conversion into context and the output of context. At this stage, the binary signal informs the control means 4 that the means 2a and the generation means 2b output the pair of context based on the matching or the mismatching of the comparison result of the predictive value and the encoding object picture element. As a result, the control means 4 makes an entropy encoding means 3 perform an encoding and output the picture element. For the encoding of an picture element, the encoding is repeated till a comparison means shows the matching.