Image data encoding/decoding method and apparatus
A method of decoding an image, includes obtaining at least one offset for a picture, deriving a variable for scaling for the picture based on the at least one offset, and performing inter prediction based on the variable for scaling for the picture. The at least one offset is defined with a direction of scaling.
1 . A method of decoding an image with a decoding apparatus, comprising:
receiving a bitstream in which the image is encoded;
obtaining, from the bitstream, index information for specifying a block division type of a current block in the image;
determining, based on the index information, the block division type of the current block from a candidate group pre-defined in the decoding apparatus,
wherein the index information is a single index, the single index is used to select one candidate division type among a plurality of candidate division types included in the candidate group,
wherein, when a size of the current block is within a predetermined range, the plurality of candidate division types includes a first quad-division, a second quad-division, and a binary-division,
wherein, when the size of the current block is out of the predetermined range, the plurality of candidate division types does not include the second quad-division,
wherein the first quad-division is representative of dividing, based on one horizontal line and one vertical line, one coding block into four coding blocks, the second quad-division is representative of dividing, based on three horizontal lines or three vertical lines, one coding block into four coding blocks, and the binary-division is representative of dividing one coding block into two coding blocks,
wherein the binary-division includes a horizontal binary-division and a vertical binary-division, and
wherein the bitstream includes a first flag specifying whether to perform the horizontal binary-division and a second flag specifying whether to perform the vertical binary-division, the first flag being different from the second flag;
dividing, based on the determined block division type, the current block into a plurality of sub-blocks; and
decoding each of the sub-blocks with reference to syntax information obtained from the bitstream,
wherein the decoding each of the sub-blocks comprises generating a prediction block of each of the sub-blocks, and
wherein the binary-division comprises a horizontal binary-division which divides one coding block into two coding blocks based on one horizontal line.
2 . A method of encoding an image with an encoding apparatus, comprising:
determining a block division type of a current block in the image from a candidate group pre-defined in the encoding apparatus,
encoding index information for specifying the determined block division type of the current block; and
encoding each of sub-blocks resulting from dividing the current block based on the determined block division type,
wherein the encoding each of the sub-blocks comprises generating a prediction block of each of the sub-blocks,
wherein the index information is a single index, the single index is used to select one candidate division type among a plurality of candidate division types included in the candidate group,
wherein, when a size of the current block is within a predetermined range, the plurality of candidate division types includes a first quad-division, a second quad-division, and a binary-division,
wherein, when the size of the current block is out of the predetermined range, the plurality of candidate division types does not include the second quad-division,
wherein the first quad-division is representative of dividing, based on one horizontal line and one vertical line, one coding block into four coding blocks, the second quad-division is representative of dividing, based on three horizontal lines or three vertical lines, one coding block into four coding blocks, and the binary-division is representative of dividing one coding block into two coding blocks,
wherein the binary-division includes a horizontal binary-division and a vertical binary-division,
wherein a first flag specifying whether to perform the horizontal binary-division and a second flag specifying whether to perform the vertical binary-division are encoded into the bitstream, the first flag being different from the second flag, and
wherein the binary-division comprises a horizontal binary-division which divides one coding block into two coding blocks based on one horizontal line.
3 . A non-transitory computer-readable recording medium storing a bitstream that is generated by a method of encoding an image with an encoding apparatus, the method comprising:
determining a block division type of a current block in the image from a candidate group pre-defined in the encoding apparatus,
encoding index information for specifying the determined block division type of the current block; and
encoding each of sub-blocks resulting from dividing the current block based on the determined block division type,
wherein the encoding each of the sub-blocks comprises generating a prediction block of each of the sub-blocks,
wherein the index information is a single index, the single index is used to select one candidate division type among a plurality of candidate division types included in the candidate group,
wherein, when a size of the current block is within a predetermined range, the plurality of candidate division types includes a first quad-division, a second quad-division, and a binary-division,
wherein, when the size of the current block is out of the predetermined range, the plurality of candidate division types does not include the second quad-division,
wherein the first quad-division is representative of dividing, based on one horizontal line and one vertical line, one coding block into four coding blocks, the second quad-division is representative of dividing, based on three horizontal lines or three vertical lines, one coding block into four coding blocks, and the binary-division is representative of dividing one coding block into two coding blocks,
wherein the binary-division includes a horizontal binary-division and a vertical binary-division,
wherein a first flag specifying whether to perform the horizontal binary-division and a second flag specifying whether to perform the vertical binary-division are encoded into the bitstream, the first flag being different from the second flag, and
wherein the binary-division comprises a horizontal binary-division which divides one coding block into two coding blocks based on one horizontal line.
4 . A method of transmitting a bitstream that is generated by a method of encoding an image with an encoding apparatus, the method of encoding the image comprising:
determining a block division type of a current block in the image from a candidate group pre-defined in the encoding apparatus,
encoding index information for specifying the determined block division type of the current block; and
encoding each of sub-blocks resulting from dividing the current block based on the determined block division type,
wherein the encoding each of the sub-blocks comprises generating a prediction block of each of the sub-blocks,
wherein the index information is a single index, the single index is used to select one candidate division type among a plurality of candidate division types included in the candidate group,
wherein, when a size of the current block is within a predetermined range, the plurality of candidate division types includes a first quad-division, a second quad-division, and a binary-division,
wherein, when the size of the current block is out of the predetermined range, the plurality of candidate division types does not include the second quad-division,
wherein the first quad-division is representative of dividing, based on one horizontal line and one vertical line, one coding block into four coding blocks, the second quad-division is representative of dividing, based on three horizontal lines or three vertical lines, one coding block into four coding blocks, and the binary-division is representative of dividing one coding block into two coding blocks,
wherein the binary-division includes a horizontal binary-division and a vertical binary-division,
wherein a first flag specifying whether to perform the horizontal binary-division and a second flag specifying whether to perform the vertical binary-division are encoded into the bitstream, the first flag being different from the second flag, and
wherein the binary-division comprises a horizontal binary-division which divides one coding block into two coding blocks based on one horizontal line.