Moving-picture coding and decoding method and apparatus with reduced computational cost

摘要

A coded moving-picture signal is decoded by a resolution-converting motion compensation process and a resolution-converting inverse discrete cosine transform, both of which decrease the resolution of the picture, thereby reducing the amount of reference picture data that has to be stored and accessed. The reference picture data may also be stored in a compressed form. The resolution conversion and compression processes may also be used in the coding of the moving-picture signal. The resolution-converting inverse discrete cosine transform may be performed by output of intermediate results that have not been combined by addition and subtraction in a butterfly computation.