Video encoding method and apparatus therefor using modification vector inducement, video decoding method and apparatus therefor

1. A video decoding method, which is performed by a video decoding apparatus, the video decoding method comprising:

obtaining a bitstream of an encoded image;

determining a prediction mode of a current block by using prediction mode information of the current block that is included in the bitstream;

determining a type of a reference vector, which indicates a reference block used for decoding the current block according to the prediction mode of the current block, as one of a motion vector type and a disparity vector type;

when a neighboring block adjacent to the current block does not have the determined type of the reference vector, generating a reference vector of the neighboring block having the determined type;

determining the reference vector of the current block indicating the reference block by using the generated reference vector of the neighboring block;

obtaining information of the reference block by using the reference vector of the current block; and

decoding the current block by using the information of the reference block.

2. The video decoding method of claim 1 , wherein the determining of the type of the reference vector, which indicates the reference block used for decoding the current block according to the prediction mode of the current block, as one of the motion vector type and the disparity vector type comprises, when the prediction mode of the current block is an inter-view prediction mode, determining the type of the reference vector of the current block as the disparity vector type.

3. The video decoding method of claim 1 , wherein the determining of the type of the reference vector, which indicates the reference block used for decoding the current block according to the prediction mode of the current block, as one of the motion vector type and the disparity vector type comprises, when the prediction mode of the current block is an inter prediction mode, determining the type of the reference vector of the current block as the disparity vector type.

4. The video decoding method of claim 1 , wherein the generating of the reference vector of the neighboring block further comprises:

when the type of the reference vector used for decoding the current block is the motion vector type, generating a motion vector of the neighboring block; and

generating the generated motion vector of the neighboring block as the reference vector of the neighboring block.

5. The video decoding method of claim 4 , wherein the generating of the motion vector of the neighboring block further comprises:

generating a disparity vector of the neighboring block indicating a block having a different view from the neighboring block; and

generating the motion vector of the neighboring block by using the disparity vector of the neighboring block.

6. The video decoding method of claim 5 , wherein the generating of the motion vector of the neighboring block by using the disparity vector of the neighboring block comprises determining a motion vector of a block indicated by the disparity vector of the neighboring block as the motion vector of the neighboring block.

7. The video decoding method of claim 1 , wherein the generating of the reference vector of the neighboring block comprises:

generating a depth value of the neighboring block by using a preset value;

generating a disparity vector of the neighboring block by using the depth value; and

generating the reference vector of the neighboring block by using the disparity vector of the neighboring block.

8. The video decoding method of claim 7 , wherein the preset value is 0, 128, or a settable maximum depth value.

9. The video decoding method of claim 1 , wherein the generating of the reference vector of the neighboring block comprises:

determining a disparity vector of a block having a decoding order one ahead of a decoding order of the current block, a disparity vector of a recently decoded block, or a zero vector, as the disparity vector of the neighboring block; and

generating the reference vector of the neighboring block by using the disparity vector of the neighboring block.

10. A video encoding method, which is performed by a video encoding apparatus, the video encoding method comprising:

determining a prediction mode of a current block;

determining a type of a reference vector, which indicates a reference block used for encoding the current block according to the prediction mode of the current block, as one of a motion vector type and a disparity vector type;

when a neighboring block adjacent to the current block does not have the determined type of the reference vector, generating a reference vector of the neighboring block having the determined type;

determining the reference vector of the current block indicating the reference block by using the generated reference vector of the neighboring block;

obtaining information of the reference block by using the reference vector of the current block;

encoding the current block by using the information of the reference block; and

generating a bitstream of the encoded current block.

11. The video encoding method of claim 10 , wherein the generating of the reference vector of the neighboring block comprises:

generating a depth value of the neighboring block by using a preset value;

generating a disparity vector of the neighboring block by using the depth value; and

generating the reference vector of the neighboring block by using the disparity vector of the neighboring block.

12. The video encoding method of claim 10 , wherein the generating of the reference vector of the neighboring block comprises:

determining a disparity vector of a block having an encoding order one ahead of an encoding order of the current block, a disparity vector of a recently decoded block, or a zero vector, as the disparity vector of the neighboring block; and

generating the reference vector of the neighboring block by using the disparity vector of the neighboring block.

13. A non-transitory computer-readable recoding recording medium having recorded thereon a computer program for executing the decoding method of claim 1 .

14. A video decoding apparatus comprising:

a bitstream obtainer configured to obtain a bitstream of an encoded image; and

a video decoder configured to:

determine a prediction mode of a current block by using prediction mode information of the current block that is included in the bitstream;

determine a type of a reference vector, which indicates a reference block used for decoding the current block according to the prediction mode of the current block, as one of a motion vector type and a disparity vector type;

when a neighboring block adjacent to the current block does not have the determined type of the reference vector, generate the reference vector of the neighboring block having the determined type;

determine the reference vector of the current block indicating the reference block by using the generated reference vector of the neighboring block;

obtain the information of the reference block by using the reference vector of the current block; and

decode the current block by using the information of the reference block.

15. A video encoding apparatus comprising:

a video encoder configured to:

determine a prediction mode of a current block;

determine a type of a reference vector, which indicates a reference block used for encoding the current block according to the prediction mode of the current block, as one of a motion vector type and a disparity vector type;

when a neighboring block adjacent to the current block does not have the determined type of the reference vector, generate a reference vector of the neighboring block having the determined type;

determine the reference vector of the current block indicating the reference block by using the generated reference vector of the neighboring block;

obtain information of the reference block by using the reference vector of the current block; and

encode the current block by using the information of the reference block; and

a bitstream generator configured to generate a bitstream of the encoded current block.