Image encoding/decoding method and device, and recording medium storing bitstream

1. A method of generating a candidate list of candidates for motion information generated in image decoding, comprising:

generating the candidate list including motion information generated using information of a neighboring block adjacent to a current block;

deriving motion information of the current block using the candidate list;

generating a prediction block of the current block using the derived motion information of the current block; and

updating a motion information list to store the derived motion information of the current block,

wherein the candidate list includes at least one of motion information included in the motion information list used for a block decoded before decoding for the current block, and

wherein the derived motion information for the current block is stored in the motion information list to be used for Intra Block Copy (IBC) mode when a size of the current block is greater than or equal to a first predetermined size and the size is less than or equal to a second predetermined size.

2. The method of claim 1 , wherein the motion information list is initialized when decoding of a predetermined region is completed so that the region is changed.

3. The method of claim 2 , wherein the predetermined region is any one of a block composed of one or more Coding Units (CUs) or a block composing of one or more Coding Tree Units (CTUs).

4. The method of claim 1 , wherein when there is a plurality of motion information in the motion information list used for the block decoded before decoding for the current block, the generating of the candidate list is performed in such a manner as to include an average of at least two or more motion information of the plurality of motion information in the candidate list.

5. The method of claim 1 , wherein when the motion information of the motion information list used for the block decoded before decoding for the current block is the same as the motion information previously included in the candidate list, the generating of the candidate list is performed in such a manner as not to include the motion information of the motion information list in the candidate list.

6. The method of claim 1 , wherein when a prediction mode for the current block is an Intra Block Copy (IBC) mode and the candidate list is a shared merge list, the updating of the motion information list is omitted.

7. The method of claim 1 , wherein when the number of motion information stored in the motion information list is a predetermined value, the updating of the derived motion information in the motion information list includes deleting the motion information first stored in the motion information list and storing the derived motion information.

8. A method of generating a candidate list of candidates for motion information generated in image encoding, comprising:

generating the candidate list including motion information generated using information of a neighboring block adjacent to a current block;

deriving motion information of the current block using the candidate list;

generating a prediction block of the current block using the derived motion information of the current block; and

updating a motion information list to store the derived motion information of the current block,

wherein the candidate list includes at least one of motion information included in the motion information list used for a block encoded before encoding for the current block, and

wherein the derived motion information for the current block is stored in the motion information list to be used for Intra Block Copy (IBC) mode when a size of the current block is greater than or equal to a first predetermined size and the size is less than or equal to a second predetermined size.

9. The method of claim 8 , wherein the motion information list is initialized when encoding of a predetermined region is completed so that the region is changed.

10. The method of claim 9 , wherein the predetermined region is any one of a block composed of one or more Coding Units (CUs) or a block composing of one or more Coding Tree Units (CTUs).

11. The method of claim 8 , wherein when there is a plurality of motion information in the motion information list used for the block encoded before encoding for the current block, the generating of the candidate list is performed in such a manner as to include an average of at least two or more motion information of the plurality of motion information in the candidate list.

12. The method of claim 8 , wherein when the motion information of the motion information list used for the block encoded before encoding for the current block is the same as the motion information previously included in the candidate list, the generating of the candidate list is performed in such a manner as not to include the motion information of the motion information list in the candidate list.

13. The method of claim 8 , wherein when a prediction mode for the current block is an Intra Block Copy (IBC) mode and the candidate list is a shared merge list, the updating of the motion information list is omitted.

14. The method of claim 8 , wherein when the number of motion information stored in the motion information list is a predetermined value, the updating of the derived motion information in the motion information list includes deleting the motion information first stored in the motion information list and storing the derived motion information.

15. A non-transitory computer-readable recording medium comprising a bitstream decoded by an image decoding method, the image decoding method comprising:

generating a candidate list including motion information generated using information of a neighboring block adjacent to a current block;

deriving motion information of the current block using the candidate list;

generating a prediction block of the current block using the derived motion information of the current block; and

updating a motion information list to store the derived motion information of the current block,

wherein the candidate list includes at least one information of motion information included in the motion information list used for a block decoded before decoding for the current block, and

wherein the derived motion information for the current block is stored in the motion information list to be used for Intra Block Copy (IBC) mode when a size of the current block is greater than or equal to a first predetermined size and the size is less than or equal to a second predetermined size.

16. A non-transitory computer-readable recording medium storing a bitstream, the bitstream comprising:

information for a prediction mode,

wherein prediction for a current block is performed using the information for the prediction mode,

wherein a candidate list including motion information generated using information of a neighboring block adjacent to a current block is generated,

wherein motion information of the current block is derived using the candidate list,

wherein a prediction block of the current block is generated using the derived motion information of the current block,

wherein a motion information list is updated to store the derived motion information of the current block,

wherein the candidate list includes at least one information of motion information included in the motion information list used for a block decoded before decoding for the current block, and

wherein the derived motion information for the current block is stored in the motion information list to be used for Intra Block Copy (IBC) mode when a size of the current block is greater than or equal to a first predetermined size and the size is less than or equal to a second predetermined size.