BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The present document is related to an inter prediction-based image coding method and device.

Related Art

Recently, demand for high-resolution, high-quality image/video such as 4K or 8K or higher ultra high definition (UHD) image/video has increased in various fields. As image/video data has high resolution and high quality, the amount of information or bits to be transmitted increases relative to the existing image/video data, and thus, transmitting image data using a medium such as an existing wired/wireless broadband line or an existing storage medium or storing image/video data using existing storage medium increase transmission cost and storage cost.

In addition, interest and demand for immersive media such as virtual reality (VR) and artificial reality (AR) content or holograms has recently increased and broadcasting for image/video is having characteristics different from reality images such as game images has increased.

Accordingly, a highly efficient image/video compression technology is required to effectively compress, transmit, store, and reproduce information of a high-resolution, high-quality image/video having various characteristics as described above.

Also, inter prediction in image/video coding may include a procedure for symmetric motion vector difference (SMVD) reference indices and/or a procedure for a merge motion vector difference (MMVD). Considering reference picture marking (for example, short-term or long-term reference), there is a discussion of applying a related technology to a procedure for SMVD reference indices.

SUMMARY

According to one embodiment of the present disclosure, a method and a device for improving image/video coding efficiency are provided.

According to one embodiment of the present disclosure, a method and a device for performing inter prediction efficiently in an image/video coding system are provided.

According to one embodiment of the present disclosure, a method and a device for signaling information on a motion vector difference in inter prediction are provided.

According to one embodiment of the present disclosure, a method and a device for signaling information on L0 motion vector differences and L1 motion vector differences are provided when bi-prediction is applied to a current block.

According to one embodiment of the present disclosure, a method and a device for signaling an SMVD flag are provided.

According to one embodiment of the present disclosure, a method and an apparatus for deriving an L1 motion vector difference based on an SMVD flag are provided.

According to one embodiment of the present disclosure, a procedure for deriving SMVD reference indices may be performed based on reference picture marking.

According to one embodiment of the present disclosure, a procedure for deriving SMVD reference indices may be performed using short-term reference pictures (marked as short-term references).

According to an embodiment of the present document, a video/image decoding method performed by a decoding apparatus is provided.

According to an embodiment of the present document, a decoding apparatus for performing video/image decoding is provided.

According to an embodiment of the present document, a video/image encoding method performed by an encoding apparatus is provided.

According to an embodiment of the present document, an encoding apparatus for performing video/image encoding is provided.

According to one embodiment of the present document, there is provided a computer-readable digital storage medium in which encoded video/image information, generated according to the video/image encoding method disclosed in at least one of the embodiments of the present document, is stored.

According to an embodiment of the present document, there is provided a computer-readable digital storage medium in which encoded information or encoded video/image information, causing to perform the video/image decoding method disclosed in at least one of the embodiments of the present document by the decoding apparatus, is stored.

ADVANTAGEOUS EFFECTS

According to the present disclosure, the overall image/video compression efficiency may be improved.

According to the present disclosure, signaling of information on motion vector differences may be performed efficiently.

According to the present disclosure, L1 motion vector differences may be efficiently derived when bi-prediction is applied to a current block.

According to the present disclosure, complexity of a coding system may be reduced by efficiently signaling the information used for deriving L1 motion vector differences.

According to one embodiment of the present disclosure, efficient inter prediction may be performed using short-term reference pictures for deriving a reference picture index of SMVD.

The technical effects achieved through specific embodiments of the present disclosure are not limited to those described above. For example, various other technical effects may be obtained, which may be understood or derived from the present disclosure by a person having ordinary skills in the related art. Therefore, specific effects of the present disclosure are not limited to the embodiments disclosed explicitly in this document and may include various other effects that may be understood or derived from the technical characteristics of the present disclosure.

