Patent ID: 9036704
Filing Date: 2015-05-19
Classification: H04N

Abstract:
1. An image decoding method comprising: reconstructing an intra prediction mode group indicator and a prediction mode index of a current block; constructing a first group including three intra prediction modes using valid intra prediction modes of left and top blocks of the current block; determining the intra prediction mode corresponding to the prediction mode index in the first group as the intra prediction mode of the current block when the intra prediction mode group indicator indicates the first group and determining the intra prediction mode corresponding to the prediction mode index in a second group when the intra prediction mode group indicator indicates the second group; and creating a prediction block on the basis of the determined intra prediction mode of the current block when a size of the current block is equal to a size of the prediction block, and creating a plurality of prediction blocks included in the current block on the basis of the determined intra prediction mode of the current block when the size of the current block is larger than the size of the prediction block, wherein the size of the prediction block is determined depending on transform size information, and when only one of the intra prediction modes of the left and top blocks of the current block is valid, two intra prediction modes are added to the first group.