PURPOSE: To realize the sub band coding method in which a video signal is compressed at a high compression efficiency and weblet conversion with less image quality deterioration in a decoded image is adopted.

CONSTITUTION: A digital video signal is divided into plural frequency bands in the vertical and horizontal directions in a spatial frequency region through 2-dimension multi-layer weblet conversion, and the signals are rearranged into plural data blocks each comprising number of data such as 8×8 for each sampling unit of the digital video signals. When data in the data blocks are scanned in a prescribed sequence to generate data strings, the data are scanned so as to easily cause 0-run. Since 0-run takes place frequently, efficient coding is conducted in the run length coding and the video signal is compressed at a high compression efficiency and the deterioration in the image quality of a decoded image is reduced.