VIDEO CODING METHOD, VIDEO ENCODER AND VIDEO CODING PROGRAM

PROBLEM TO BE SOLVED: To recover the image quality efficiently from a state where simple coding is used frequently after intra-picture insertion, or the like.SOLUTION: In the intra-picture, a predetermined region is set in a normal coding region R1, and other regions are set in a simple coding region R2. In the subsequent picture, the normal coding region R1 is set in a larger region including the normal coding region R1 of a previous picture, and other regions are set in a simple coding region R2. In each picture, normal coding is performed in the block of the normal coding region R1, and simple coding where the amount of codes generated and the amount of computation are smaller than those of the normal coding is performed in the block of simple coding region.