CONTEXT BASED ARITHMETIC ENCODER

摘要

PURPOSE: A context based arithmetic encoder capable of simultaneously calculating the number of outputs and the number of filling bits by detecting a non-zero bit of a probability value is provided. CONSTITUTION: A context based arithmetic encoder comprising: a context producing section(10) for receiving a bit value of an adjacent boundary pixel and an index of a plurality of bits; a symbol probability value output section for outputting a symbol probability value of a corresponding address in response to the index from the context producing section(10); a symbol arithmetic encoder(30) for multiplying the symbol probability value from the symbol probability value output section by a transition probability value and outputting an accumulating probability value; an estimator(90) for calculating a transition bit and a filling bit based on the accumulating probability value from the symbol arithmetic encoder(30) and outputting the transition probability value and a first output bit; a code ending section for producing a second output bit based on an accumulating probability value of a final pixel from the symbol arithmetic encoder(30); and an output section for sequentially receiving and storing the first and second bits and outputting coded bits.