PICTURE ENCODOR

PURPOSE:To improve encoding efficiency by generating a motion differential picture signal by motion-compensation between two picture signals continuous in point of time, and variable-length-encoding it after orthogonal-transforming and quantizing it. CONSTITUTION:The picture signal at present is predicted from two reduced picture signals of a low frequency component picture signal which is processed by an LPF 2, a sampling circuit 3, a frame memory 6, etc., and is continuous in the point of time, and a motion difference is generated by a motion compensation circuit 7, and is orthogonal-transformed by a discrete cosine transducer 4, and a low frequency component is encoded by a quantizer 5 and 8 variable code length encoder 8. The output of this quantizer 5 is supplied through an expansion circuit 9, and a high frequency component difference is generated, and a high frequency component is encoded similarly. Through the use of constitution to use correlation on a time base by performing the motion compensation on the reduced picture, the encoding efficiency can be extremely enhanced.