Method for signaling image information, and method for decoding image information using same
The present invention relates to a method offor signaling information on a prediction mode and to a method of for decoding image information using same. According to the present invention, the method offor signaling prediction mode information, serving according to the present invention, as a method offor signaling image information, includes performing prediction on a current block and signaling the prediction-type information applied to the current block. The signaling of the information includes joint-coding and components of signaling information components constituting the prediction-type information. According to the present invention, overhead may be reduced when information on a prediction is signaled.
1. An image prediction method, by a decoding apparatus, the method comprising:
receiving a bitstream including prediction information of a current block;
determining a prediction mode applied to the current block based on the prediction information; and
performing a prediction with regard to the current block based on the prediction mode,
wherein determining the prediction mode includes:
decoding a skip flag indicating whether a skip mode is applied to the current block; and
decoding a merge flag indicating whether a merge mode is applied to a partition of the current block, when the skip flag represents value 0,
wherein the skip flag and the merge flag are included in the prediction information,
wherein the prediction information includes partition mode information representing a partition type of the current block, and
wherein decoding of the partition mode information is performed between decoding of the skip flag and decoding of the merge flag.
2. The method of claim 1 , wherein in the prediction based on the merge mode, a motion vector of a neighboring block to the partition is used as a motion vector of the partition.
3. The method of claim 1 , wherein the partition type for inter prediction is one of partition types including 2N×2N partition type, 2N×N partition type, and N×2N partition type, and
wherein a codeword for the 2N×2N partition type is “1”, a codeword for the 2N×N partition type is “01”, and a codeword for the N×2N partition type is “001”.
4. The method of claim 1 , wherein a short codeword is allocated to the partition mode information representing a partition type with a high frequency of occurrence.
5. The method of claim 1 , wherein the prediction information comprises prediction mode information indicating whether inter prediction or intra prediction is applied to the current block,
wherein decoding of the prediction mode information is performed between decoding of the skip flag and decoding of the merge flag.
6. The method of claim 1 , wherein the prediction information comprises prediction mode information indicating whether inter prediction or intra prediction is applied to the current block,
wherein decoding of the prediction mode information is performed between decoding of the skip flag and decoding of the merge flag.
7. The method of claim 1 , wherein when the merge flag represent value 0, a motion vector of the partition is derived based on (i) a motion vector of a neighboring block to the partition, and (ii) an additional motion vector value,
wherein the derived motion vector is obtained by adding the motion vector of the neighboring block and the additional motion vector value, wherein the additional motion vector value is obtained from the prediction information.
8. The method of claim 1 , further comprising:
receiving a split flag with respect to a coding unit; and
deriving a current coding unit based on the split flag before the checking the skip flag.
9. The method of claim 8 , wherein the current block is the current coding unit.
10. The method of claim 8 , wherein N×N partition type is available only when a size of the current coding unit is same as a size of a minimum coding unit.
11. The method of claim 10 , wherein a codeword for the N×N partition type consists of multiple values of 0 without a value of 1.