VARIABLE LENGTH CODING METHOD AND VARIABLE LENGTH DECODING METHOD

摘要

A variable length encoding method for frequency converting image data in a moving picture in block unit having a predetermined size and encoding a coefficient value in each of the blocks. The method includes a coefficient value scan step for scanning the coefficient values in a block in a predetermined order and an encoding step for switching a plurality of tables used for encoding and encoding the coefficient values scanned in the coefficient value scan step into variable length codes in a predetermined order. Here, the switching of the aforementioned tables may be in one direction. Moreover, the aforementioned encoding may be non-arithmetic encoding.