US-20260129244-A1 - IN-LOOP FILTERING IN MAPPING-BASED VIDEO CODING

US20260129244A1US 20260129244 A1US20260129244 A1US 20260129244A1US-20260129244-A1

Abstract

A method of performing in-loop filtering for a target pixel, by a video decoding device, includes determining whether a mapping relation is to be applied to the target pixel. When the mapping relation is applied, the method further includes decoding information on the mapping relation; determining an offset for the target pixel by using the information on the mapping relation; and performing the offset filtering on the target pixel by using the offset.

Inventors

Sea Nae Park
Joo Hyung Byeon
Dong Gyu Sim
Jin Heo
Seung Wook Park

Assignees

HYUNDAI MOTOR COMPANY
KIA CORPORATION
KWANGWOON UNIVERSITY INDUSTRY-ACADEMIC COLLABORATION FOUNDATION

Dates

Publication Date: 20260507
Application Date: 20260102
Priority Date: 20211217

Claims (6)

1 . A method of performing in-loop filtering for a target pixel, by a video decoding device, the method comprising: determining whether a mapping relation is to be applied to the target pixel, wherein, when the mapping relation is applied, the method further comprises: decoding information on the mapping relation; determining an offset for the target pixel by using the information on the mapping relation; and performing the offset filtering on the target pixel by using the offset.
2 . The method of claim 1 , wherein, when edge offset filtering is used, determining the offset for the target pixel comprises: determining mapping intervals assigned to the target pixel and two neighboring pixels respectively by using the information on the mapping relation, wherein the target pixel and the two neighboring pixels are located in a line centered on the target pixel; and determining the offset of the target pixel based on the mapping intervals.
3 . The method of claim 2 , wherein determining the offset for the target pixel further comprises: adaptively factoring a gradient value of the mapping interval assigned to the target pixel into the offset.
4 . The method of claim 1 , wherein, when band offset filtering is used, determining the offset for the target pixel comprises: dividing intervals that are subject to a band offset as equally with mapping intervals according to the mapping relation, and applying the band offset to each of the intervals.
5 . A method of performing in-loop filtering for a target pixel, by a video encoding device, the method comprising: determining whether a mapping relation is to be applied to the target pixel, wherein, when the mapping relation is applied, the method further comprises: determining information on the mapping relation; determining an offset for the target pixel by using the information on the mapping relation; performing the offset filtering on the target pixel by using the offset; and encoding the information on the mapping relation.
6 . A method for providing a video decoding device with video data, the method comprising: encoding the video data into a bitstream; and transmitting the bitstream to the video decoding device, wherein encoding the video data comprises: determining whether a mapping relation is to be applied to a target pixel, wherein, when the mapping relation is applied, the method further comprises: determining information on the mapping relation; determining an offset for the target pixel by using the information on the mapping relation; performing the offset filtering on the target pixel by using the offset; and encoding the information on the mapping relation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of non-provisional U.S. patent application Ser. No. 18/737,419, filed on Jun. 7, 2024, which is a continuation of International Application No. PCT/KR2022/017026 filed on Nov. 2, 2022, which claims priority to and the benefit of Korean Patent Application No. 10-2021-0181830, filed on Dec. 17, 2021, and Korean Patent Application No. 10-2022-0143933, filed on Nov. 1, 2022, the entire contents of each of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to in-loop filtering in mapping-based video coding. BACKGROUND The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. Since video data has a large amount of data compared to audio or still image data, the video data requires a lot of hardware resources, including a memory, to store or transmit the video data without processing for compression. Accordingly, an encoder is generally used to compress and store or transmit video data. A decoder receives the compressed video data, decompresses the received compressed video data, and plays the decompressed video data. Video compression techniques include H.264/AVC, High Efficiency Video Coding (HEVC), and Versatile Video Coding (VVC), which has improved coding efficiency by about 30% or more compared to HEVC. However, since the image size, resolution, and frame rate gradually increase, the amount of data to be encoded also increases. Accordingly, a new compression technique providing higher coding efficiency and an improved image enhancement effect than existing compression techniques is required. To effectively compress a video image, a mapping may be applied to the original signals or residual signals to change the range of sample values, and then encoding or decoding may be performed. When the original signals or residual signals are mapped in a certain way and then encoded or decoded, the coding efficiency may be increased, but changes in signal characteristics between blocks or within blocks may occur during the mapping and transform process. Therefore, to enhance video quality and improve coding efficiency, there is a need for a method of dealing with such changes in signal characteristics. SUMMARY The present disclosure seeks to provide a video coding method and an apparatus for compensating for variations in signal characteristics between or within blocks by using in-loop filtering when original signals or residual signals are mapped in a particular way and then video encoding or video decoding is performed. At least one aspect of the present disclosure provides a method of performing in-loop filtering by a video decoding device. The method includes determining a target region for deblocking filtering centered on a boundary between blocks in a reconstructed image. The method also includes determining whether a mapping relation is to be applied to pixels in the target region. When the mapping relation is applied, the method further includes decoding information on the mapping relation, calculating a mapping offset by using the information on the mapping relation, and performing the deblocking filtering on the target region by using the mapping offset. Another aspect of the present disclosure provides a method of performing in-loop filtering by a video encoding device. The method includes determining a target region for deblocking filtering centered on a boundary between blocks in a reconstructed image. The method also includes determining whether a mapping relation is to be applied to pixels in the target region. When the mapping relation is applied, the method further includes determining information on the mapping relation, calculating a mapping offset by using the information on the mapping relation, performing the deblocking filtering on the target region by using the mapping offset, and encoding the information on the mapping relation. Yet another aspect of the present disclosure provides a computer-readable recording medium storing a bitstream generated by a video encoding method. The video encoding method includes determining a target region for deblocking filtering centered on a boundary between blocks in a reconstructed image. The video encoding method also includes determining whether a mapping relation is to be applied to pixels in the target region. When the mapping relation is applied, the video encoding method further includes determining information on the mapping relation, calculating a mapping offset by using the information on the mapping relation, performing the deblocking filtering on the target region by using the mapping offset, and encoding the information on the mapping relation. As described above, the present disclosure provides a video coding method and an apparatus that compensate for changes in signal characteristics between blocks or within a block by using in-loop