INTER-FRAME CODE ENCODING DEVICE OF VECTOR QUANTIZATION SYSTEM

PURPOSE:To provide a device which is immune to disturbance of Gaussian noise and does not much reduce the encoding efficiency even in the case of a moving picture by controlling a minimum distortion output vector to zero vector at the time when the distance of the minimum distortion output vector from the origin is shorter than the set value which can be controlled correspondingly to an input vector in the processing unit of the input vector. CONSTITUTION:A minimum distortion output vector detector 29 detects the output vector which minimizes the distortion between input and output vectors and sends a strobe signal to an index latch 30. An index (i) corresponding to the address of an output vector yi which has a minimum distortion to each input vector xi is latched in the index latch 30. A threshold level is set to this index (i), and the value of (i) is sent by a threshold circuit 31 in the case of excess over a prescribed level, and a special code is sent by this circuit 31 as zero vector in the other case. The output of the threshold circuit 31 is sent as an output vector encoded signal 18 to a vector quantization encoder.