The disclosure relates to image decoding.
According to image compression standards such as the Moving Picture Experts Group (MPEG)-1, MPEG-2, and MPEG-4 H.264/MPEG-4 advanced video coding (AVC), in order to encode an image, a picture is divided into blocks of a predetermined size and each block is encoded by performing inter prediction or intra prediction. An optimal encoding mode is selected in consideration of a rate-distortion (R-D) cost and a block is encoded according to the selected encoding mode.
In an image encoding method using inter prediction, an image is compressed by removing temporal redundancy between pictures. A motion estimation encoding method is a representative example of the image encoding method using inter prediction. In the motion estimation encoding method, an image is encoded by estimating and compressing motion of a current picture in blocks by using at least one reference picture.