BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The present disclosure relates to an image coding technique and, more particularly, to an image coding method and an apparatus therefor, in coding residual data according to TSRC of a current block in an image coding system, in the case that all maximum available context-coded bins for the current block are used, for coding the subsequent residual data according to a simplified residual data coding structure.

Related Art

Recently, demand for high-resolution, high-quality images, such as High Definition (HD) images and Ultra High Definition (UHD) images, has been increasing in various fields. As the image data has high resolution and high quality, the amount of information or bits to be transmitted increases relative to the legacy image data. Therefore, when image data is transmitted using a medium such as a conventional wired/wireless broadband line or image data is stored using an existing storage medium, the transmission cost and the storage cost thereof are increased.

Accordingly, there is a need for a highly efficient image compression technique for effectively transmitting, storing, and reproducing information of high-resolution and high-quality images.

SUMMARY

The present disclosure provides a method and apparatus for improving image coding efficiency.

The present disclosure also provides a method and apparatus for improving residual coding efficiency.

According to an embodiment of this document, an image decoding method performed by a decoding apparatus is provided. The method includes obtaining residual information of a current block, deriving residual samples of the current block based on the residual information, and generating a reconstructed picture based on the residual samples.

According to another embodiment of this document, a decoding apparatus performing image decoding is provided. The decoding apparatus includes an entropy decoder configured to obtain residual information of a current block, a residual processor configured to derive residual samples of the current block based on the residual information, and an adder configured to generate a reconstructed picture based on the residual samples.

According to still another embodiment of this document, an image encoding method performed by an encoding apparatus is provided. The method includes deriving residual samples for a current block, generating residual information for the residual samples, and encoding image information including the residual information.

According to still another embodiment of this document, an image encoding apparatus is provided. The encoding apparatus includes a residual processor configured to derive residual samples for a current block and an entropy encoder configured to generate residual information for the residual samples and encode image information including the residual information.

According to still another embodiment of this document, a non-transitory computer-readable storage medium storing a bitstream including image information causing an image decoding method to be performed is provided. In the non-transitory computer-readable storage medium, the image decoding method includes obtaining residual information of a current block, deriving residual samples of the current block based on the residual information, and generating a reconstructed picture based on the residual samples.

According to the present disclosure, the efficiency of residual coding may be improved.

According to the present disclosure, when the maximum number of context-coded bins for a current block is consumed in TSRC, syntax elements according to a simplified residual data coding structure may be signaled, and through this, the coding complexity of bypass-coded syntax elements is reduced, and the overall residual coding efficiency may be improved.

According to the present disclosure, as a coding order of bypass-coded syntax elements, an order in which a syntax element is preferential may be used, and through this, the coding efficiency of the bypass-coded syntax elements may be improved, and the overall residual coding efficiency may be improved.

