Method and device for image encoding and decoding, and recording medium having bit stream stored therein
Disclosed is a method of decoding an image and a method of encoding an image. The method of decoding an image includes: obtaining motion-constrained tile set information; determining, on the basis of the motion-constrained tile set information, a first boundary region of a collocated tile set within a reference picture, which corresponds to a motion-constrained tile set; padding a second boundary region corresponding to the first boundary region; and performing inter prediction on the motion-constrained tile set by using a collocated tile set that includes the padded second boundary region.
1. A method of decoding an image, the method comprising:
obtaining motion-constrained region information;
deriving motion information; and
performing inter prediction based on the motion-constrained region information and the motion information,
when the motion-constrained region information indicates that motion-constrained region is applied, a configuration of motion-constrained region of a reference picture used for inter prediction is equal to a configuration of motion-constrained region of a current picture, and
when a reference sample value outside the motion-constrained region of the reference picture is required for the inter prediction, wherein the inter prediction is performed by using a sample value of a boundary of the motion-constrained region of the reference picture instead of the reference sample value outside the motion-constrained region of the reference picture.
2. The method of claim 1 , wherein the motion-constrained region represents a region where independent decoding process is performed.
3. The method of claim 1 , wherein the configuration of motion-constrained region includes a number of motion-constrained regions and a location for each of the motion-constrained regions.
4. The method of claim 1 , wherein the deriving motion information comprises:
constructing a motion information candidate list; and
deriving the motion information using the motion information candidate list,
wherein the motion information candidate list is constructed based on the motion-constrained region.
5. A method of encoding an image, the method comprising:
determining motion-constrained region information;
determining motion information; and
performing inter prediction based on the motion-constrained region information and the motion information,
when the motion-constrained region information indicates that motion-constrained region is applied, a configuration of motion-constrained region of a reference picture used for inter prediction is equal to a configuration of motion-constrained region of a current picture, and
when a reference sample value outside the motion-constrained region of the reference picture is required for the inter prediction, wherein the inter prediction is performed by using a sample value of a boundary of the motion-constrained region of the reference picture instead of the reference sample value outside the motion-constrained region of the reference picture.
6. A computer-readable non-transitory recording medium storing a bitstream formed by a method of encoding an image, the method comprising:
determining motion-constrained region information;
determining motion information; and
performing inter prediction based on the motion-constrained region information and the motion information,
when the motion-constrained region information indicates that motion-constrained region is applied, a configuration of motion-constrained region of a reference picture used for inter prediction is equal to a configuration of motion-constrained region of a current picture, and
when a reference sample value outside the motion-constrained region of the reference picture is required for the inter prediction, wherein the inter prediction is performed by using a sample value of a boundary of the motion-constrained region of the reference picture instead of the reference sample value outside the motion-constrained region of the reference picture.