Method and apparatus for encoding/decoding image, on basis of available slice type information for gdr or irap picture, and recording medium storing bitstream

An image encoding method performed by an image encoding apparatus, the image encoding method comprising:

• encoding first information on whether an inter slice type is allowed for a current picture including a current block;
• and
• encoding second information on whether an intra slice type is allowed for the current picture, based on the inter slice type being allowed for the current picture,
• wherein whether the inter slice type is allowed for the current picture is determined based on a picture type of the current picture and whether a current layer including the current picture is an independent layer to be decoded without reference to other layers.

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

• encoding first information on whether an inter slice type is allowed for a current picture including a current block;
• and
• encoding second information on whether an intra slice type is allowed for the current picture, based on the inter slice type being allowed for the current picture,
• wherein whether the inter slice type is allowed for the current picture is determined based on a picture type of the current picture and whether a current layer including the current picture is an independent layer to be decoded without reference to other layers.