MOTION IMAGE CODER

摘要

PURPOSE: To improve the processing speed while keeping the image quality by referencing a measured coding processing history so as to limit adaptively the retrieval range of the coding mode or the coding parameter. CONSTITUTION: A coding history measurement section 15 receives a preceding coding history up to a preceding frame or field to measure values such as a utility factor required for processing efficiency. A coding mode parameter limit section 16 limits adaptively the retrieval range of the coding mode and/or coding parameter to quicken the coding processing without causing deterioration in the image quality on a threshold level stored in advance in a decision reference storage section 17 and a measured value from the measurement section 15. The limit section 16 is reset to an initial value given from an initial value storage section 19 in response to the periodic reset signal given from a frame clock section 18. The measurement section is provided with a prediction mode utility measurement section, a processing structure utility measurement section and a motion vector histogram generating section to measure respective utility factor.