The present invention relates to an encoding method and decoding method, and a device using the same. The encoding method according to the present invention comprises the steps of: specifying an intra prediction mode for a current block; and scanning a residual signal by intra prediction of the current block, wherein the step of scanning the residual signal can determine a scanning type for a luminance signal and a chroma signal of the current block according to an intra prediction mode for a luminance sample of the current block.

A motion vector coding unit executes processing including a neighboring block specification step of specifying a neighboring block which is located in the neighborhood of a current block; a judgment step of judging whether or not the neighboring block has been coded using a motion vector of another block; a prediction step of deriving a predictive motion vector of the current block using a motion vector calculated from the motion vector of the other block as a motion vector of the neighboring block; and a coding step of coding the motion vector of the current block using the predictive motion vector.

A motion vector coding unit executes processing including a neighboring block specification step of specifying a neighboring block which is located in the neighborhood of a current block; a judgment step of judging whether or not the neighboring block has been coded using a motion vector of another block; a prediction step of deriving a predictive motion vector of the current block using a motion vector calculated from the motion vector of the other block as a motion vector of the neighboring block; and a coding step of coding the motion vector of the current block using the predictive motion vector.

A variable length coding method is comprised of: a coefficient value scanning step in which an RL sequence generation unit, a reordering unit, and a binarization unit scan coefficient values within a block in a predetermined scanning order starting at a higher-frequency component toward a lower-frequency component; and an arithmetic coding step in which an arithmetic coding unit and a table storage unit perform arithmetic coding on the absolute values of the coefficient values according to the scanning order used in the coefficient value scanning step, by switching between probability tables for use, wherein, in the arithmetic coding step, a probability table to be used is switched to another probability table in one direction, when the arithmetic-coded absolute values of the coefficient values include an absolute value exceeding a predetermined threshold value.

A video encoding method and apparatus and a video decoding method and apparatus are provided. The video encoding method includes: prediction encoding in units of a coding unit as a data unit for encoding a picture, by using partitions determined based on a first partition mode and a partition level, so as to select a partition for outputting an encoding result from among the determined partitions; and encoding and outputting partition information representing a first partition mode and a partition level of the selected partition. The first partition mode represents a shape and directionality of a partition as a data unit for performing the prediction encoding on the coding unit, and the partition level represents a degree to which the coding unit is split into partitions for detailed motion prediction.

A video encoding method and apparatus and a video decoding method and apparatus are provided. The video encoding method includes: prediction encoding in units of a coding unit as a data unit for encoding a picture, by using partitions determined based on a first partition mode and a partition level, so as to select a partition for outputting an encoding result from among the determined partitions; and encoding and outputting partition information representing a first partition mode and a partition level of the selected partition. The first partition mode represents a shape and directionality of a partition as a data unit for performing the prediction encoding on the coding unit, and the partition level represents a degree to which the coding unit is split into partitions for detailed motion prediction.

Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. A multi-level scan order may be used in which significant-coefficient flags are scanned group-by-group. The group scan order specifies the order in which the groups are processed, and the scan order specifies the order in which individual significant-coefficient flags within the group are processed. The bitstream may interleave the significant-coefficient-group flags and their corresponding significant-coefficient flags, if any.

Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. A multi-level scan order may be used in which significant-coefficient flags are scanned group-by-group. The group scan order specifies the order in which the groups are processed, and the scan order specifies the order in which individual significant-coefficient flags within the group are processed. The bitstream may interleave the significant-coefficient-group flags and their corresponding significant-coefficient flags, if any.

According to the present invention, an image encoding apparatus comprises: a motion prediction unit which derives motion information on a current block in the form of the motion information including L0 motion information and L1 motion information; a motion compensation unit which performs a motion compensation for the current block on the basis of at least one of the L0 motion information and L1 motion information so as to generate a prediction block corresponding to the current block; and a restoration block generating unit which generates a restoration block corresponding to the current block based on the prediction block. According to the present invention, image encoding efficiency can be improved.

A method of encoding an image in a merge mode, the method including determining motion information of a current prediction unit, and generating a prediction block using the motion information; generating a residual block using an original block and the prediction block, transforming the residual block to generating a transformed block, quantizing the transformed block using a quantization parameter to generate a quantized block, and scanning the quantized block to entropy-code the quantized block; and encoding the motion information using effective spatial and temporal merge candidates of the current prediction unit. Further, a motion vector of the temporal merge candidate is a motion vector of a temporal merge candidate within a temporal merge candidate picture, and the quantization parameter is encoded using an average of two effective quantization parameters among a left quantization parameter, an upper quantization parameter and a previous quantization parameter of a current coding unit, also when the quantized block is larger than a predetermined size, the quantized block is divided into a plurality of subblocks to be scanned, and a scan pattern for scanning the plurality of subblocks is the same as a scan pattern for scanning quantized coefficients within each subblock. In addition, information indicating a position of a last non-zero quantized coefficient in a transform unit is transmitted to a video decoder.