PURPOSE: To attain high speed transmission through a low speed transmission line even in a rough total image of a high definition picture by deciding a representative value for each block group comprising two blocks or more and generating a code through the use of the value.
CONSTITUTION: Received code data are decoded into a block representative value at a decoding section 1, the number of decoded data is fed to a block position count section 5, in which a block position of a representative value, that is, x-, y-coordinates are calculated. The block representative value obtained by the decoding section 1 is fed simultaneously to a representative value calculation start control section 2 and the block position of the count section 5 is fed to the control section 2, from which a calculation command and a representative value are given to a calculation section 3, and the obtained representative value is coded into a variable length code and outputted as coded data by a coding section 4. The control section 2 and the calculation section 3 are connected to a memory access management section 6, and the representative value address from the section 6 is stored in a block representative value storage section 7. Thus, the reduced picture is displayed in a short time.
MORIHARA TAKASHI
NODA TSUGUO
