PURPOSE: To attain the refresh processing in the unit of lines by sending a refresh start signal to inform a refresh time to a receiver side only once for the refresh period.

CONSTITUTION: A frame number count 2 and a line number count 4 are inputted to a refresh timing circuit 102, from which a refresh control signal 5 and a refresh start signal 6 are outputted to a coding circuit. The refresh control signal 5 is inputted to a switch 104, a quantization device 105 and an inverse quantizer 100 and when the refresh control signal 5 is at a high level, terminals (b), (c) of the switch 105 are connected and a prediction signal 9c goes to '0'. Thus, the picture signal 7 is directly inputted to the quantizer 105, a coded picture signal 10 is obtained to execute the refresh operation. The refresh control signal 5 is fed to the quantizer 105, which receives a special characteristic at refresh and applies quantization.