Provided is a method for decoding a video signal. The method includes generating a first prediction sample by performing intra prediction on a current block, determining an intra prediction pattern of a current block, partitioning the current block into a plurality of sub-blocks based on the determined intra prediction pattern, generating a first prediction sample for a sub-block by performing intra prediction, determining an offset for the sub-block to obtain a second prediction sample, and generating the second prediction sample for the sub-block by using the first prediction sample and the offset.