Mage encoding/decoding method and device for signaling information related to sub picture and picture header, and method for transmitting bitstream

An image encoding method comprising:

• encoding a first flag specifying whether information on a subpicture is present in a bitstream;
• encoding a second flag specifying whether picture header information is present in a slice header;
• and
• encoding the bitstream based on the first flag and the second flag,
• wherein the first flag is encoded into a sequence parameter set (SPS), and
• wherein, based on the first flag specifying that the information on the subpicture is present in the bitstream, the second flag is restricted to have a value specifying that the picture header information is not present in the slice header.

A method of transmitting a bitstream generated by an image encoding method, the image encoding method comprising:

• encoding a first flag specifying whether information on a subpicture is present in a bitstream;
• encoding a second flag specifying whether picture header information is present in a slice header;
• and
• encoding the bitstream based on the first flag and the second flag,
• wherein the first flag is encoded into a sequence parameter set (SPS), and
• wherein, based on the first flag specifying that the information on the subpicture is present in the bitstream, the second flag is restricted to have a value specifying that the picture header information is not present in the slice header.

A non-transitory computer readable recording medium storing a bitstream which is generated by an image encoding method, the image encoding method comprising:

• encoding a first flag specifying whether information on a subpicture is present in a bitstream;
• encoding a second flag specifying whether picture header information is present in a slice header;
• and
• encoding the bitstream based on the first flag and the second flag,
• wherein the first flag is encoded into a sequence parameter set (SPS), and
• wherein, based on the first flag specifying that the information on the subpicture is present in the bitstream, the second flag is restricted to have a value specifying that the picture header information is not present in the slice header.