VIDEO OR IMAGE CODING APPLYING ADAPTIVE LOOP FILTER

An image decoding method, according to the present disclosure may comprise: acquiring, from a bitstream, image information including adaptive loop filter (ALF) information including, alternative filter information for a chroma component of a current block, and residual information; generating reconstructed samples for the current block on the basis of the residual information; and generating modified reconstructed samples for the chroma component of the current block on the basis of the alternative filter information.