a memory; and

at least one processor connected to the memory, the at least one processor configured to:

receive a bitstream including image information, wherein the image information includes a picture header associated with a current picture, and a plurality of slices are included in the current picture;

parse, from the picture header, a syntax element specifying whether all the slices in the current picture are I slices;

derive prediction samples by performing at least one of intra prediction or inter prediction on blocks in the slices in the current picture based on the syntax element specifying whether all the slices in the current picture are the I slices; and

generate reconstructed samples based on the derived prediction samples,

wherein based on the syntax element specifying that one or more of the slices in the current picture are a P slice or B slice, information for an inter slice including a syntax element representing a maximum hierarchy depth for a coding unit resulting from multi-type tree splitting in the inter slice in the current picture is comprised in the picture header, and

wherein based on the syntax element specifying that all the slices in the current picture are the I slices, information for an intra slice including a syntax element representing a maximum hierarchy depth for a coding unit resulting from multi-type tree splitting in the intra slice in the current picture and a syntax element representing a difference between base 2 logarithm of a minimum size resulting from quad-tree splitting and base 2 logarithm of a minimum coding block size in the intra slice in the current picture is comprised in the picture header.