Image decoding apparatus with object area decoding means and shape decoding means

摘要

An image decoding apparatus which receives an encoded signal and decodes the encoded signal, comprising: first decoding means for decoding the encoded signal to obtain a difference value of a pixel value signal and outputting the obtained difference value as a decoded difference pixel value; third decoding means for decoding the encoded signal to obtain a pixel value motion vector and a shape signal motion vector and ouputting these motion vectors as a decoded pixel value motion vector and a decoded shape motion vector, respectively; first motion compensation means for compensating a pixel value signal of a reference image using the decoded pixel value motion vector and outputting the result of the motion compensation as the compensated pixel value signal; first calculation means for adding the decoded difference pixel value signal and the compensated pixel value signal and outputting the result of the addition as a decoded pixel value signal; second motion compensation means for compensating a shape signal of the reference image using the decoded shape motion vector and outputting the result of the motion compensation as a compensated shape signal; and second decoding means for decoding the encoded signal with reference to the compensated shape signal and outputting the decoded signal as a decoded shape signal; wherein said third decoding means decodes the pixel value motion vector and a difference value between the pixel value motion vector and the shape motion vector to obtain a decoded pixel value motion vector and a decoded motion vector difference value and adds the decoded pixel value motion vector and the decoded motion vector difference value to obtain a decoded shape signal motion vector. <IMAGE>