According to an embodiment, the image decoding apparatus 100 may recursively split coding units. Referring to FIG. 7, the image decoding apparatus 100 may determine the plurality of coding units 710a and 710b, 730a and 730b, or 750a to 750d by splitting the first coding unit 700, and recursively split each of the determined plurality of coding units 710b, 730a and 730b, or 750a to 750d. A splitting method of the plurality of coding units 710b, 730a and 730b, or 750a to 750d may correspond to a splitting method of the first coding unit 700. As such, each of the plurality of coding units 710b, 730a and 730b, or 750a to 750d may be independently split into a plurality of coding units. Referring to FIG. 7, the image decoding apparatus 100 may determine the second coding units 710a and 710b by splitting the first coding unit 700 in a vertical direction, and may determine to independently split or not to split each of the second coding units 710a and 710b.
According to an embodiment, the image decoding apparatus 100 may determine third coding units 720a and 720b by splitting the left second coding unit 710a in a horizontal direction, and may not split the right second coding unit 710b.