Encoding/decoding method and apparatus for coding unit partitioning
Disclosed is an image decoding method using the correlation between color components to perform into prediction of chrominance components. Here, the image decoding method using the correlation between color components to perform intra prediction of chrominance components comprises the steps of: checking image data and a prediction mode in a bitstream; generating a prediction block according to a reconstructed prediction mode; determining compensation settings according to the size of a current block and the reconstructed prediction mode; compensating the prediction block according to the determined compensation settings; and reconstructing the current block by adding reconstructed image data to the prediction block.
1. An image decoding method performed by an image decoding apparatus ( 30 ) comprising a prediction unit ( 310 ) and an adder ( 325 ), the image decoding method comprising:
generating, by the prediction unit ( 310 ), a prediction pixel of a current block of a first color space, the prediction pixel of the current block being generated by using a plurality of reference pixels belonging to a corresponding block of a second color space;
deriving, by the prediction unit ( 310 ), correlation information between the current block of the first color space and the corresponding block of the second color space, using a first neighboring region adjacent to the current block of the first color space and a second neighboring region adjacent to the corresponding block of the second color space;
correcting, by the prediction unit ( 310 ), the prediction pixel of the current block based on the correlation information;
obtaining, by the image decoding apparatus ( 30 ), a residual pixel for the current block; and
reconstructing, by the adder ( 325 ), the current block of the first color space based on the corrected prediction pixel and the residual pixel,
wherein generating the prediction pixel of the current block of the first color space comprises performing a filtering on the reference pixels belonging to the corresponding block of the second color space,
wherein the reference pixels include at least one of a filtering target pixel or a neighboring pixel of the filtering target pixel,
wherein the neighboring pixel of the filtering target pixel includes at least one of a top pixel, a left pixel, a right pixel, a top-left pixel, a top-right pixel, a bottom pixel, a bottom-left pixel, or a bottom-right pixel adjacent to the filtering target pixel, and
wherein a number of the reference pixels to be used to generate the prediction pixel of the current block of the first color space is variably determined based on a flag signaled from an encoding apparatus.
2. The image decoding method of claim 1 ,
wherein a position of each of the first neighboring region and the second neighboring region is determined based on an intra prediction mode of the current block of the first color space.
3. The image decoding method of claim 2 ,
wherein the first neighboring region includes at least one of a top region, a left region, a top-left region, a bottom-left region or a top-right region of the current block of the first color space.
4. The image decoding method of claim 1 , wherein deriving the correlation information comprises:
determining a plurality of pixels for correcting the prediction pixel of the current block, among pixels belonging to the second neighboring region adjacent to the corresponding block of the second color space; and
generating one pixel by applying a weighting filter to the determined plurality of pixels.
5. An image encoding method performed by an image encoding apparatus ( 20 ) comprising a prediction unit ( 200 ), the image encoding method comprising:
generating, by the prediction unit ( 200 ), a prediction pixel of a current block of a first color space, the prediction pixel of the current block being generated by using a plurality of reference pixels belonging to a corresponding block of a second color space;
deriving, by the prediction unit ( 200 ), correlation information between the current block of the first color space and the corresponding block of the second color space, using a first neighboring region adjacent to the current block of the first color space and a second neighboring region adjacent to the corresponding block of the second color space;
correcting, by the prediction unit ( 200 ), the prediction pixel of the current block based on the correlation information;
generating, by the image encoding apparatus ( 20 ), a residual pixel for the current block based on the corrected prediction pixel; and
encoding, by the image encoding apparatus ( 20 ), the current block of the first color space based on the residual pixel,
wherein generating the prediction pixel of the current block of the first color space comprises performing a filtering on the reference pixels belonging to the corresponding block of the second color space,
wherein the reference pixels include at least one of a filtering target pixel or a neighboring pixel of the filtering target pixel,
wherein the neighboring pixel of the filtering target pixel includes at least one of a top pixel, a left pixel, a right pixel, a top-left pixel, a top-right pixel, a bottom pixel, a bottom-left pixel or a bottom-right pixel adjacent to the filtering target pixel, and
wherein a flag for determining a number of the reference pixels to be used to generate the prediction pixel of the current block of the first color space is encoded.
6. A method of transmitting a bitstream performed by an image encoding apparatus ( 20 ) comprising a prediction unit ( 200 ), the method comprising:
generating, by the prediction unit ( 200 ), a prediction pixel of a current block of a first color space, the prediction pixel of the current block being generated by using a plurality of reference pixels belonging to a corresponding block of a second color space;
deriving, by the prediction unit ( 200 ), correlation information between the current block of the first color space and the corresponding block of the second color space, using a first neighboring region adjacent to the current block of the first color space and a second neighboring region adjacent to the corresponding block of the second color space;
correcting, by the prediction unit ( 200 ), the prediction pixel of the current block based on the correlation information;
generating, by the image encoding apparatus ( 20 ), a residual pixel for the current block based on the corrected prediction pixel;
encoding, by the image encoding apparatus ( 20 ), the current block of the first color space based on the residual pixel to generate the bitstream; and
transmitting, by the image encoding apparatus ( 20 ), the generated bitstream to an image decoding apparatus,
wherein generating the prediction pixel of the current block of the first color space comprises performing a filtering on the reference pixels belonging to the corresponding block of the second color space,
wherein the reference pixels include at least one of a filtering target pixel or a neighboring pixel of the filtering target pixel,
wherein the neighboring pixel of the filtering target pixel includes at least one of a top pixel, a left pixel, a right pixel, a top-left pixel, a top-right pixel, a bottom pixel, a bottom-left pixel or a bottom-right pixel adjacent to the filtering target pixel, and
wherein a flag for determining a number of the reference pixels to be used to generate the prediction pixel of the current block of the first color space is encoded.
7. A method of transmitting a bitstream generated by an image encoding method, wherein the image encoding method comprising:
generating, by a prediction unit ( 200 ), a prediction pixel of a current block of a first color space, the prediction pixel of the current block being generated by using a plurality of reference pixels belonging to a corresponding block of a second color space;
deriving, by the prediction unit ( 200 ), correlation information between the current block of the first color space and the corresponding block of the second color space, using a first neighboring region adjacent to the current block of the first color space and a second neighboring region adjacent to the corresponding block of the second color space;
correcting, by the prediction unit ( 200 ), the prediction pixel of the current block based on the correlation information;
generating, by an image encoding apparatus ( 20 ), a residual pixel for the current block based on the corrected prediction pixel;
encoding, by the image encoding apparatus ( 20 ), the current block of the first color space based on the residual pixel to generate the bitstream; and
transmitting, by the image encoding apparatus ( 20 ), the generated bitstream to an image decoding apparatus,
wherein generating the prediction pixel of the current block of the first color space comprises performing a filtering on the reference pixels belonging to the corresponding block of the second color space,
wherein the reference pixels include at least one of a filtering target pixel or a neighboring pixel of the filtering target pixel,
wherein the neighboring pixel of the filtering target pixel includes at least one of a top pixel, a left pixel, a right pixel, a top-left pixel, a top-right pixel, a bottom pixel, a bottom-left pixel or a bottom-right pixel adjacent to the filtering target pixel, and
wherein a flag for determining a number of the reference pixels to be used to generate the prediction pixel of the current block of the first color space is encoded.
8. A non-transitory computer-readable storage medium storing a bitstream that is generated by a method of encoding an image, the method of encoding the image comprising:
generating, by a prediction unit ( 200 ), a prediction pixel of a current block of a first color space, the prediction pixel of the current block being generated by using a plurality of reference pixels belonging to a corresponding block of a second color space;
deriving, by the prediction unit ( 200 ), correlation information between the current block of the first color space and the corresponding block of the second color space, using a first neighboring region adjacent to the current block of the first color space and a second neighboring region adjacent to the corresponding block of the second color space;
correcting, by the prediction unit ( 200 ), the prediction pixel of the current block based on the correlation information;
generating, by an image encoding apparatus ( 20 ), a residual pixel for the current block based on the corrected prediction pixel; and
encoding, by the image encoding apparatus ( 20 ), the current block of the first color space based on the residual pixel,
wherein generating the prediction pixel of the current block of the first color space comprises performing a filtering on the reference pixels belonging to the corresponding block of the second color space,
wherein the reference pixels include at least one of a filtering target pixel or a neighboring pixel of the filtering target pixel,
wherein the neighboring pixel of the filtering target pixel includes at least one of a top pixel, a left pixel, a right pixel, a top-left pixel, a top-right pixel, a bottom pixel, a bottom-left pixel or a bottom-right pixel adjacent to the filtering target pixel, and
wherein a flag for determining a number of the reference pixels to be used to generate the prediction pixel of the current block of the first color space is encoded.