Image coding/decoding method and apparatus therefor

The present invention discloses an image coding/decoding method and an apparatus therefor. Specifically, a method for filtering, by a decoding apparatus, an image comprises the steps of: deriving a boundary of a block divided into a quadtree plus binary tree structure; determining, among the boundary of the block, an edge to which de-blocking filtering is applied; determining a type of de-blocking filtering to be applied to the edge; and performing the de-blocking filtering on a picture sample restored according to the type of the de-blocking filtering, wherein the edge or the type of the de-blocking filtering may be determined in consideration of a width or a height of the block.