1. A method for decoding a video signal, comprising: obtaining, with a video coding apparatus, position information of a current block in a current image in an enhanced layer; obtaining, with the video coding apparatus, offset information between at least one boundary pixel of a reference image and at least one boundary pixel of the current image, the reference image being up-sampled from an image in a base layer, the offset information including, left offset information indicating a position offset between at least one left side pixel of the reference image and at least one left side pixel of the current image, top offset information indicating a position offset between at least one top side pixel of the reference image and at least one top side pixel of the current image, right offset information indicating a position offset between at least one right side pixel of the reference image and at least one right side pixel of the current image, and bottom offset information indicating a position offset between at least one bottom side pixel of the reference image and at least one bottom side pixel of the current image; obtaining, with the video coding apparatus, position information of a reference block in the reference image based on the position information of the current block and the offset information; obtaining, with the video coding apparatus, a reference pixel value based on the position information of the reference block; and decoding, with the video coding apparatus, the current block based on the reference pixel value.