METHOD AND DEVICE FOR IMAGE ENCODING

摘要

PURPOSE:To prevent compression efficiency from being lowered by setting a threshold value from the frequency distribution of a block corresponding to block activity when dividing image data into plural hierarchical data and encoding them. CONSTITUTION:The image encoding device is composed of a hierarchical encoder part 40A for hierarchically encoding and outputting input image data D1 and a generated information quantity control part 40B for performing control so that the quantity of information generated at the encoder part 40A can reach a target value. The encoder part is composed of a memory for data delay and an encoder. Among these elements, the memory is provided for preventing encode processing from being executed before an optimum control value is decided at the control part 40B. On the other hand, the control part 40B is provided for deciding a threshold value TH adaptive to processing object data. Then, the optimum control value is transmitted to the encoder so that the input image data can be efficiently encoded at the encoder part 40A.