IMAGE DATA ENCODING/DECODING METHOD AND APPARATUS
Disclosed are methods and apparatuses for decoding an image. A method includes receiving a bitstream obtained by encoding the image; dividing a first coding block into a plurality of second coding blocks; generating a prediction block of a second coding block based on syntax information obtained from the bitstream; and reconstructing the second coding block based on the prediction block and a residual block of the second coding block, the residual block being obtained by performing a dequantization and an inverse-transform on quantized transform coefficients from the bitstream. The first coding block has a recursive division structure. The first coding block is divided based on at least one of a quad tree division, a binary tree division or a triple tree division.
1 . An image decoding method performed by an image decoding apparatus, the image decoding method comprising:
deriving a size of a subblock based on at least one of a size of a current block or a shape of the current block;
partitioning the current block into one or more subblocks based on the size of the subblock;
performing inverse-transformation for the subblock; and
generating a residual signal based on the inverse-transformation.
2 . The method of claim 1 ,
wherein, in case the current block is square, a quadtree partitioning is performed for the current block, and
wherein, in case the current block is rectangular, a binary tree partitioning is performed for the current block.
3 . The method of claim 1 ,
wherein the partitioning the current block is performed based on a predetermined index for a partitioning, and
wherein, in case the current block is a 4N×4N block, the current block is not partitioned, or the current block is partitioned into four 2××2N subblocks, or the current block is partitioned into sixteen N×N subblocks.
4 . The method of claim 1 ,
wherein selection information indicating whether a partitioning shape for transformation of the current block is determined adaptively is obtained from a bitstream, and
wherein the partitioning the current block is performed based on the selection information.
5 . The method of claim 1 ,
wherein the partitioning the current block is performed differently according to whether a prediction mode of the current block is an inter mode or an intra mode.
6 . An image encoding method performed by an image encoding apparatus, the image encoding method comprising:
deriving a size of a subblock based on at least one of a size of a current block or a shape of the current block;
partitioning the current block into one or more subblocks based on the size of the subblock;
performing transformation for the subblock; and
encoding a residual signal based on the transformation.
7 . A non-transitory computer-readable recording medium storing a bitstream that is generated by an image encoding method performed by an image encoding apparatus, the image encoding method comprising:
deriving a size of a subblock based on at least one of a size of a current block or a shape of the current block;
partitioning the current block into one or more subblocks based on the size of the subblock;
performing transformation for the subblock; and
encoding the residual signal based on the transformation.
8 . A method of transmitting a bitstream that is generated by an image encoding method performed by an image encoding apparatus, the image encoding method comprising:
deriving a size of a subblock based on at least one of a size of a current block or a shape of the current block;
partitioning the current block into one or more subblocks based on the size of the subblock;
performing transformation for the subblock; and
encoding the residual signal based on the transformation.