Image encoding/decoding method and device for signaling filter information on basis of chroma format, and method for transmitting bitstream

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

• determining a chroma array type of a current image;
• and
• generating a bitstream by encoding an adaptive loop filter (ALF) indicator specifying a chroma component to which an ALF applies, based on the chroma array type of the current image,
• wherein a value of the ALF indicator is not encoded, based on the chroma array type being a monochrome type, and
• wherein the value of the ALF indicator is encoded, based on the chroma array type not being the monochrome type.

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

• determining a chroma array type of a current image;
• and
• generating a bitstream by encoding an adaptive loop filter (ALF) indicator specifying a chroma component to which an ALF applies, based on the chroma array type of the current image,
• wherein a value of the ALF indicator is not encoded, based on the chroma array type being a monochrome type, and
• wherein the value of the ALF indicator is encoded, based on the chroma array type not being the monochrome type.