| 摘要 |
PROBLEM TO BE SOLVED: To improve encoding efficiency by predicting a notice picture element from a peripheral picture element, estimating the appearing probability of a predicted picture element based on it, selecting a symbol whose appearing probability is high and executing arithmetic encoding on the symbol. SOLUTION: A notice picture element input means 201 inputs the notice picture element becoming an encoding object and the value of the notice picture element is predicted from the situation of the peripheral picture element of the notice picture element. A prediction probability estimation means 202 estimates the appearing probability of a predicted value. An appearing probability calculation means 203 calculates the appearing probability of the real picture element value from the real picture element value and the predicted value. When the appearing probability of the real picture element value is lower than a previously decided value, a symbol change means 204 changes the symbol before the encoding processing and it is substituted for the symbol whose appearing probability is high. Then, arithmetic encoding is executed in the arithmetic encoding means 205 by using appearing probability after a symbol change processing and a code is generated. Thus, encoding becomes possible with considerably high efficiency. |
