Syntax-based adaptive arithmetic encoder and/or decoder using locational probabilistic model and high efficiency image encoder and/or decoder using adaptive arithmetic encoder and/or decoder

PURPOSE: A syntax-based adaptive arithmetic encoder and/or decoder using a locational probabilistic model and a high efficiency image encoder and/or decoder using the syntax-based adaptive arithmetic encoder and/or decoder are provided to improve the probability model by using the locational probabilistic model of an AC(Alternating Current) coefficient. CONSTITUTION: An index value generator(101) changes an inputted discrete cosine transformation coefficient into index values of a last(201), a level(202), and a run(203). An encoder calculates a generated coefficient position to output position information by using the index values outputted from the index value generator(101). The encoder encodes an input sign by using predetermined probability information and supplies the latest information for a probability model of the input sign. A syntax-based multiple signal processor(103) selects a probability model corresponding to the calculated position among first to fourth probability models(PM0,PM1,PM2,PMr;104,105,106,107) by using the position information outputted from the encoder. The syntax-based multiple signal processor(103) selects the probability information of the selected probability model among first to probability information(P;207,209,211,213) to apply it to the encoder. The syntax-based multiple signal processor(103) updates the corresponding probability model by using the latest information outputted from the encoder.