METHODS AND DEVICES FOR ENCODING AND DECODING IMAGE SIGNAL AND STORAGE MEDIUM RECORDING THE SAME METHODS

摘要

PROBLEM TO BE SOLVED: To provide an encoding method/device and a decoding method/device for providing an intermediate resolution, with which a satisfactory decoded picture quality can be provided by the designated compressibility, without searching any optimum point. SOLUTION: An optimum resolution selector 4 obtains an optimum intermediate resolution 6 corresponding to the designated compressibility out of a table corresponding to a designated encoder retrieved from an optimum resolution table storage device 5 and outputs it to a resolution converter 7. The resolution converter 7 sets the internal states of a band limiter 8 and a resampler 9 for limiting the band of an image corresponding to the optimum intermediate resolution 6 and outputs a source image resolution 10 and a reduced image signal 11. An image signal encoding device 12 encodes a reduced image signal 11 and a multiplexer 14 multiplexes the information of the source image resolution 10 and encoded data 13 and outputs them as transmission data 15 later. On the stage of decoding, these transmission data are demultiplexed to encoded data and the source image resolution and the reduced image decoding the encoded data is converted to the image signal of the original resolution by the source image resolution.