The present invention relates to a method for reconstructing a video signal through a low complexity discrete sine transform7 (DST7) design, the method comprising the steps of: acquiring a transform index of a current block from the video signal, wherein the transform index corresponds to one among a plurality of transform combinations including a combination of DST7 and/or discrete cosine transform8 (DST8); deriving a transform combination corresponding to the transform index, wherein the transform combination includes a horizontal transform and a vertical transform, and the horizontal transform and the vertical transform correspond to one of DST7 and DST8; performing an inverse transform in the vertical or horizontal direction on the current block by using DST7 or DST8; and reconstructing the video signal by using the inversely transformed current block, wherein a 33-point discrete Fourier transform (DFT) is applied to DST7 when DST7 is 16x16, and a 65-point DFT is applied to DST7 when DST7 is 32x32.
展开▼
