METHOD FOR ENCODING IMAGE, METHOD FOR DECODING IMAGE, IMAGE ENCODER, AND IMAGE DECODER

摘要

The present invention relates to a technique to encode and decode an image. According to the present invention, a method of encoding an image includes the steps of: performing a prediction with respect to a current block; and transforming a residual generated by the prediction wherein in the transforming step, a first transform is performed on the residual, and a second transform is performed on a lower frequency area wherein a mode of the second transform can be decided based on a mode of the first transform.