Image signal processing device

Abstract

An image signal processing device enables renewal of probability presumption information to be processed in high speed using logical circuit. A transition state renewal part implements maintenance/renewal of status ('ST') value corresponding to respective contexts ('CX') and more probability symbol (‘MPS’) value of the ‘CX’. An ‘A’-register operation part implements subtraction between value of ‘A’-register and occurrence probability (‘LSZ’) of low probability symbol (‘LPS’), shift of the ‘A’-register. A probability transition table outputs corresponding ‘LSZ’, next objective of transition (‘NMPS’) in the case of ‘MPS’, next objective of transition (‘NLPS’) when ‘PIX’ is ‘LPS’, and value of occurrence of inversion of ‘MPS’ value (‘SWTCH’) in answer to value of ‘ST’ inputted therein. An ‘C’-register operation part implements addition/subtraction between value of ‘C’-register and value of ‘A’-register and/or shift of the ‘C’-register. Thus cycle of read and write of probability presumption information for generating timing of input/output of signal due to a ‘CT’ renewal part is implemented in high speed, with the result that processing speed of the whole coding processing is improved.