Picture coding method and picture coder

Abstract

A picture coder and a picture coding method which quickly recover the degraded picture quality of partitions, which could not be decoded due to a data error or a data loss, without increasing the amount of coding. A picture coding method or a picture coder is operable for coding picture data of a frame which is divided into a plurality of partitions, each partition being coded in a temporal correlation coding method or in an intra-picture coding method, wherein one or more partitions are determined to be refreshed for each frame or for each plurality of frames and wherein partitions determined to be refreshed are coded in the intra-picture coding method. A temporal change amount for each partition is calculated and, based on the temporal change amount for each partition, one or more partitions are determined to be refreshed.