Sample adaptive offset (SAO) adjustment method and apparatus and SAO adjustment determination method and apparatus
A video encoding method and apparatus, and a video decoding method and apparatus for generating a reconstructed image having a minimized error between an original image and the reconstructed image. The video decoding method accompanied by a sample adaptive offset (SAO) adjustment, the method includes: obtaining 5 slice SAO parameters with respect to a current slice from a slice header of a received bitstream; obtaining luma SAO use information for a luma component of the current slice and chroma SAO use information for chroma components thereof from among the slice SAO parameters; determining whether to perform a SAO operation on the luma component of 10 the current slice based on the obtained luma SAO use information; and equally determining whether to perform the SAO adjustment on a first chroma component and a second chroma component of the current slice based on the obtained chroma SAO use information.
1. A video decoding apparatus comprising:
a processor which is configured for performing entropy decoding on a bitstream and obtaining left offset merging information of a current block, and compensating for samples of the current block by using offset values,
wherein:
when the left offset merging information indicates that an offset parameter of the current block is determined according to an offset parameter of a left block, the processor is configured for determining the offset parameter of the current block using the offset parameter of the left block,
when the left offset merging information indicates that the offset parameter of the current block is not determined according to the offset parameter of the left block, the processor is configured for obtaining upper offset merging information of the current block by performing entropy decoding on the bitstream,
when the upper offset merging information indicates that the offset parameter of the current block is determined according to an offset parameter of an upper block, the processor is configured for determining the offset parameter of the current block using the offset parameter of the upper block, and
when the upper offset merging information indicates that the offset parameter of the current block is not determined according to an offset parameter of the upper block, the processor is configured for obtaining offset parameter of the current block from the bitstream,
the offset parameter comprises at least one of offset type information and the offset values,
the offset type information indicates an offset type or whether to apply an offset to the current block, and
the offset type is one of a band offset type and an edge offset type,
wherein, when the processor is configured for obtaining the offset parameter of the current block from the bitstream:
when the offset type information of the current block indicates the band offset type or the edge offset type, the processor is configured for obtaining absolute values of the offset of the current block by performing entropy decoding on the bitstream in bypass mode,
in response to determining that the offset type information of the current block indicates the band offset type, the processor is configured for obtaining a band class indicating a starting point of bands of the current block by performing entropy decoding on the bitstream after obtaining of the absolute values of the offset, and
when the offset type information of the current block indicates the edge offset type, the processor is configured for obtaining an edge class indicating an edge direction of the current block by performing entropy decoding on the bitstream,
wherein:
when one bit of the left offset merging information is obtained from the bitstream, the one bit of the left offset merging information is applied to luma components, Cr chroma components and Cb chroma components of the current block,
when one bit of the upper offset merging information is obtained from the bitstream, the one bit of the upper offset merging information is applied to the luma components, the Cr chroma components and the Cb chroma components of the current block,
when an edge direction for the Cr chroma components is determined by an edge class for the Cr chroma components of the current block, an edge direction for the Cb chroma components of the current block is determined to be identical to the edge direction for the Cr chroma components, and
a band class for the Cb chroma components and a band class for the Cr chroma components are obtained from the bitstream, respectively.