Method and apparatus for encoding and decoding image by using large transform unit
A method of decoding an image in which wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of at least one prediction unit in the coding unit is determined independently from a size of at least one transformation unit in the coding unit.
1. A method of decoding an image, the method comprising:
performing entropy decoding to generate quantized transformation coefficients of a transformation unit in a coding unit;
performing inverse-quantization on the quantized transformation coefficients to generate transformation coefficients of the transformation unit;
performing inverse-transformation on the transformation coefficients to generate residual components of the transformation unit,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the transformation unit in the coding unit is determined independently from a size of a prediction unit in the coding unit,
the image is split into a plurality of maximum coding units, according to information about a maximum size of the coding unit,
the maximum coding unit is hierarchically split into one or more coding units of depth including at least one of a current depth and a lower depth, according to split information,
when the split information indicates a split for the current depth, a coding unit of the current depth is split into four rectangular coding units of a lower depth, independently from neighboring coding units, and
when the split information indicates a non-split of the current depth, the prediction unit is obtained from the coding unit of the current depth and the transformation unit is obtained from the coding unit of the current depth.
2. A method of encoding an image, the method comprising:
generating information about a maximum size of a coding unit, used to split an image into a plurality of maximum coding units;
generating split information used to hierarchically split a maximum coding unit, among the plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth;
generating transformation coefficients of a transformation unit by performing transformation and quantization on residual components; and
generating a bitstream including the information about the maximum size of the coding unit, the split information, and the transformation coefficients,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the transformation unit in the coding unit, among the one or more coding units, is determined independently from a size of a prediction unit in the coding unit,
when a coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the prediction unit is obtained from the coding unit of the current depth and the transformation unit is obtained from the coding unit of the current depth, the split information indicates a non-split of the current depth.
3. A non-transitory computer-readable storage medium having embodied thereon computer-readable codes, which when executed by processor of an encoder causes the encoder to execute a method of encoding an image, the method comprising:
generating a bitstream comprising:
information about a maximum size of a coding unit, used to split an image into a plurality of maximum coding units;
split information used to hierarchically split a maximum coding unit, among the plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth; and
transformation coefficients of a transformation unit generated by performing transformation and quantization on residual components,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the transformation unit in the coding unit, among the one or more coding units, is determined independently from a size of a prediction unit in the coding unit,
when a coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the prediction unit is obtained from the coding unit of the current depth and the transformation unit is obtained from the coding unit of the current depth, the split information indicates a non-split of the current depth.
4. A method of encoding an image, the method comprising:
generating information about a maximum size of a coding unit used to split the image into a plurality of maximum coding units;
generating split information used to hierarchically split a maximum coding unit, among the plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth;
performing inter prediction for at least one prediction unit in a coding unit, among the one or more coding units, to generate a predictor;
generating transformation coefficients of at least one transformation unit based on the image and the predictor; and
generating a bitstream including the information about the maximum size of the coding unit, the split information, and the transformation coefficients;
wherein, when a prediction mode is determined to be an inter prediction mode, not an intra prediction mode, a size of the at least one transformation unit in the coding unit is determined regardless of a size of the at least one prediction unit in the coding unit,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the at least one prediction unit is obtained from the coding unit of the lower depth, the split information indicates a non-split of the lower depth.
5. A non-transitory computer-readable storage medium having embodied thereon computer-readable codes, which when executed by a processor of an encoder causes the encoder to execute a method of encoding an image, the method comprising:
generating a bitstream comprising:
information about a maximum size of a coding unit used to split the image into a plurality of maximum coding units;
split information used to hierarchically split a maximum coding unit, among the plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth; and
transformation coefficients of at least one transformation unit based on the image and a predictor,
wherein the predictor is generated by performing inter prediction for at least one prediction unit in a coding unit, among the one or more coding units,
wherein, when a prediction mode is determined to be an inter prediction mode, not an intra prediction mode, a size of the at least one transformation unit in the coding unit is determined regardless of a size of the at least one prediction unit in the coding unit,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the at least one prediction unit is obtained from the coding unit of the lower depth, the split information indicates a non-split of the lower depth.
6. An apparatus for encoding an image, the apparatus comprising:
at least one processor configured to:
generate information about a maximum size of a coding unit used to split an image into a plurality of maximum coding units;
generate split information used to hierarchically split a maximum coding unit, among the plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth;
generate transformation coefficients by performing transformation on residual components of a transformation unit;
generate a bitstream including the information about a maximum size of a coding unit, the split information, and the transformation coefficients,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the transformation unit in a coding unit, among the one or more coding units, is determined independently from a size of a prediction unit in the coding unit,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the prediction unit is obtained from the coding unit of the current depth and the transformation unit is obtained from the coding unit of the current depth, the split information indicates a non-split of the current depth.
7. A non-transitory computer-readable storage medium having embodied thereon computer-readable codes, which when executed by a processor of an encoder causes the encoder to execute a method of encoding an image, the method comprising:
generating a bitstream comprising:
information about a maximum size of a coding unit used to split an image into a plurality of maximum coding units;
split information used to hierarchically split a maximum coding unit, among the plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth; and
transformation coefficients by performing transformation on residual components of a transformation unit,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the transformation unit in a coding unit, among the one or more coding units, is determined independently from a size of a prediction unit in the coding unit,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the prediction unit is obtained from the coding unit of the current depth and the transformation unit is obtained from the coding unit of the current depth, the split information indicates a non-split of the current depth.
8. A method of encoding an image, the method comprising:
generating split information used to hierarchically split a maximum coding unit, from among a plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth,
performing inter prediction for at least one prediction unit in a coding unit among the one or more coding units of the image to generate a predictor;
generating transformation coefficients of at least one transformation unit in the coding unit of the image, based on the predictor and the image; and
generating a bitstream including the split information and the transformation coefficients,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the at least one prediction unit in the coding unit is determined independently from a size of the at least one transformation unit in the coding unit,
the image is split into the plurality of maximum coding units,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the at least one prediction unit is obtained from the coding unit of the lower depth and the at least one transformation unit is obtained from the coding unit of the lower depth, the split information indicates a non-split of the lower depth.
9. A non-transitory computer-readable storage medium having embodied thereon computer-readable codes, which when executed by a processor of an encoder causes the encoder to execute a method of encoding an image, the method comprising:
generating a bitstream comprising:
split information used to hierarchically split a maximum coding unit, from among a plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth; and
transformation coefficients of at least one transformation unit in a coding unit, among the one or more coding units of the image, based on a predictor and the image,
wherein the predictor is generated by performing inter prediction for at least one prediction unit in the coding unit,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the at least one prediction unit in the coding unit is determined independently from a size of the at least one transformation unit in the coding unit,
the image is split into the plurality of maximum coding units,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the at least one prediction unit is obtained from the coding unit of the lower depth and the at least one transformation unit is obtained from the coding unit of the lower depth, the split information indicates a non-split of the lower depth.
10. An apparatus for encoding an image, the apparatus comprising:
at least one processor configured to:
generate split information used to hierarchically split a maximum coding unit, from among a plurality of maximum coding units, into one or more coding units of depth including at least one of a current depth and a lower depth, perform inter prediction for at least one prediction unit in a coding unit among the one or more coding units of the image to generate a predictor;
generate transformation coefficients of at least one transformation unit in the coding unit based on the predictor and the image; and
generate a bitstream including the split information and the transformation coefficients,
wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of the at least one prediction unit in the coding unit is determined independently from a size of the at least one transformation unit in the coding unit,
the image is split into the plurality of maximum coding units, and
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units the split information indicates a split for the current depth, and
when the at least one prediction unit is obtained from the coding unit of the lower depth and the at least one transformation unit is obtained from the coding unit of the lower depth, the split information indicates a non-split of the lower depth.
11. A non-transitory computer-readable storage medium having embodied thereon computer-readable codes, which when executed by a processor of an encoder causes the encoder to execute a method of encoding an image, the method comprising:
generating a bitstream comprising:
information about a maximum size of a coding unit used to split the image into a plurality of maximum coding units;
split information used to hierarchically split a maximum coding unit among the plurality of maximum coding units into one or more coding units of depth including at least one of a current depth and a lower depth;
information used to determine a prediction mode for at least one prediction unit in a coding unit, among the one or more coding units; and
transformation coefficients of at least one transformation unit based on the image and a predictor
wherein the predictor is generated by performing inter prediction for the at least one prediction unit in the coding unit;
wherein when the prediction mode is determined to be an inter prediction mode, not an intra prediction mode, a size of the at least one transformation unit in the coding unit is determined regardless of a size of the at least one prediction unit in the coding unit,
when the coding unit of the current depth is split into four square coding units of the lower depth, independently from neighboring coding units, the split information indicates a split for the current depth, and
when the coding unit of the current depth is split into the at least one prediction unit, the split information indicates a non-split of the current depth.