公开(公告)号：US11902508B2

公开(公告)日：2024-02-13

申请号：US17466930

申请日：2021-09-03

Applicant: Huawei Technologies Co., Ltd.

Inventor： Sriram Sethuraman ,  Sagar Kotecha ,  Jeeva Raj A

IPC: H04N19/105 ,  H04N19/132 ,  H04N19/137 ,  H04N19/159 ,  H04N19/176

CPC classification number: H04N19/105 ,  H04N19/132 ,  H04N19/137 ,  H04N19/159 ,  H04N19/176

Abstract: A method for inter prediction of a block of a picture and corresponding apparatus are provided. The method comprises: determining a first prediction block based on an initial first motion vector of a current block in a first reference picture, so as to obtain a first extension block; obtaining from the first reference picture, one or more first reference blocks each of which is associated with a combination of the initial first motion vector and one of motion vector offsets; obtaining a target motion vector offset with a smallest cost among the motion vector offsets; determining for the current block, a refined first motion vector which is a combination of the initial first motion vector and the target motion vector offset; and obtaining a refined prediction block of the current block based on the refined first motion vector, thereby improving coherence of refined motion vectors to achieve higher coding efficiencies.

公开(公告)号：US20220368888A9

公开(公告)日：2022-11-17

申请号：US17466129

申请日：2021-09-03

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Semih ESENLIK ,  Jeeva Raj A ,  Sagar KOTECHA

IPC: H04N19/105 ,  H04N19/132 ,  H04N19/137 ,  H04N19/159 ,  H04N19/46 ,  H04N19/176

Abstract: The present disclosure provides an inter prediction method, comprising the steps of obtaining an initial motion vector and a reference picture for bi-prediction; obtaining sets of candidate sample positions in the reference picture according to the initial motion vector and candidate motion vectors, wherein each candidate motion vector is derived by the initial motion vector and a respective motion vector offset, and wherein each set of candidate sample positions corresponds to each candidate motion vector; obtaining a respective set of sample positions from each set of candidate sample positions; computing a matching cost for each candidate motion vector within each set of sample positions; obtaining a refined motion vector based on the computed matching cost of each candidate motion vector; and obtaining prediction values for a current block based on the refined motion vector.

公开(公告)号：US20220132158A1

公开(公告)日：2022-04-28

申请号：US17573331

申请日：2022-01-11

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/513 ,  H04N19/523

Abstract: Given that decoder side motion vector refinement/derivation is a normative aspect of a coding system, the encoder will also have to perform the same error surface technique in order to not have any drift between the encoder's reconstruction and the decoder's reconstruction. Hence, all aspects of all embodiments are applicable to both encoding and decoding systems. In template matching, the refinement movement occurs only in the reference starting from the sub-pixel accurate center that is derived based on the explicitly signaled merge index or implicitly through cost evaluations. In bilateral matching (with or without averaged template), the refinements start in the reference lists L0 and L1 starting from the respective sub-pixel accurate centers that are derived based on the explicitly signaled merge index or implicitly through cost evaluations.

公开(公告)号：US11272205B2

公开(公告)日：2022-03-08

申请号：US17100924

申请日：2020-11-22

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/513 ,  H04N19/523

Abstract: Given that decoder side motion vector refinement/derivation is a normative aspect of a coding system, the encoder will also have to perform the same error surface technique in order to not have any drift between the encoder's reconstruction and the decoder's reconstruction. Hence, all aspects of all embodiments are applicable to both encoding and decoding systems. In template matching, the refinement movement occurs only in the reference starting from the sub-pixel accurate center that is derived based on the explicitly signaled merge index or implicitly through cost evaluations. In bilateral matching (with or without averaged template), the refinements start in the reference lists L0 and L1 starting from the respective sub-pixel accurate centers that are derived based on the explicitly signaled merge index or implicitly through cost evaluations.

公开(公告)号：US20210329257A1

公开(公告)日：2021-10-21

申请号：US17308311

申请日：2021-05-05

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Jeeva Raj A ,  Sagar KOTECHA

IPC: H04N19/159 ,  H04N19/105 ,  H04N19/132 ,  H04N19/513 ,  H04N19/176

Abstract: Methods and system, including decoders and encoders, for interprediction. In one aspect, a method includes selecting reference samples based on motion information of a current picture block of a current picture, deriving first interpolated samples by performing a first interpolation on the selected reference samples, deriving an integer distance delta motion vector for a target sub-prediction unit (PU) by performing integer-distance MVR, deriving M×M pixel matrix flow vectors by performing BPOF, for each M×M pixel matrix in the target sub-PU, based on the first interpolated samples and the integer distance delta motion vector, deriving second interpolated samples by performing a second interpolation on the reference samples, computing at least one correction parameter for the target sub-PU based on the M×M pixel matrix flow vectors, the first interpolated samples and the second interpolated samples, and performing bi-prediction based on the second interpolated samples and the at least one correction parameter.

公开(公告)号：US11109060B2

公开(公告)日：2021-08-31

申请号：US16815914

申请日：2020-03-11

Applicant: Huawei Technologies Co., Ltd.

Inventor： Shan Gao ,  Huanbang Chen ,  Haitao Yang ,  Jiantong Zhou ,  Shan Liu ,  Sriram Sethuraman ,  Jay Shingala ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/176 ,  H04N19/523 ,  H04N19/56

Abstract: An image prediction method and apparatus includes obtaining predicted motion information of an image block; determining an initial predicted block of the image block according to the predicted motion information and a reference image of the image block; performing, according to the predicted motion information, L iterative searches in the reference image using an integer pixel step size to obtain an intermediate predicted block of the image block; performing a single search in the reference image using a fractional pixel step size to obtain M predicted blocks of the image block; determining a target predicted block of the image block according to the M predicted blocks and the intermediate predicted block; and obtaining a predicted value of a pixel value of the image block according to a pixel value of the target predicted block.

公开(公告)号：US20210076059A1

公开(公告)日：2021-03-11

申请号：US17100924

申请日：2020-11-22

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Jeeva Raj A ,  Sagar KOTECHA

IPC: H04N19/513 ,  H04N19/523

Abstract: Given that decoder side motion vector refinement/derivation is a normative aspect of a coding system, the encoder will also have to perform the same error surface technique in order to not have any drift between the encoder's reconstruction and the decoder's reconstruction. Hence, all aspects of all embodiments are applicable to both encoding and decoding systems. In template matching, the refinement movement occurs only in the reference starting from the sub-pixel accurate center that is derived based on the explicitly signaled merge index or implicitly through cost evaluations. In bilateral matching (with or without averaged template), the refinements start in the reference lists L0 and L1 starting from the respective sub-pixel accurate centers that are derived based on the explicitly signaled merge index or implicitly through cost evaluations.

公开(公告)号：US20250088637A1

公开(公告)日：2025-03-13

申请号：US18954675

申请日：2024-11-21

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Jeeva Raj A ,  Sagar KOTECHA

IPC: H04N19/137 ,  H04N19/105 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176

Abstract: A method for bi-directional optical flow prediction based on reference sample values from sample positions belonging to an extended region of a predicted block used in the bi-directional optical flow prediction of a current block is provided, wherein sub-pixel positions in the extended region of the predicted block in the reference picture are rounded to obtain integer pixel sample positions in the reference picture, wherein the reference sample values at the obtained integer pixel sample positions in the reference picture are used in the computation of boundary sample gradients corresponding to the boundaries of the predicted block in the reference picture.

公开(公告)号：US20240283938A1

公开(公告)日：2024-08-22

申请号：US18592849

申请日：2024-03-01

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Semih ESENLIK ,  Sriram SETHURAMAN ,  Jeeva Raj A ,  Sagar KOTECHA

IPC: H04N19/132 ,  H04N19/117 ,  H04N19/159 ,  H04N19/176 ,  H04N19/82

CPC classification number: H04N19/132 ,  H04N19/117 ,  H04N19/159 ,  H04N19/176 ,  H04N19/82

Abstract: It is provided a method of video coding implemented in a decoding device or an encoding device, the method comprising: obtaining initial motion vectors for a current block; obtaining first predictions for a sample value in the current block based on the initial motion vectors; calculating a first matching cost according to the first predictions; determining whether an optical flow refinement process should be performed or not, according to at least one preset condition, the at least one preset condition comprising a condition of whether the calculated first matching cost is equal to or larger than a threshold value; and performing an optical flow refinement process for obtaining a final inter prediction for the sample value in the current block, when it is determined that the optical flow refinement process should be performed.

公开(公告)号：US20240244255A1

公开(公告)日：2024-07-18

申请号：US18423846

申请日：2024-01-26

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Jeeva Raj A ,  Sagar KOTECHA

IPC: H04N19/577 ,  H04N19/132 ,  H04N19/172 ,  H04N19/176

CPC classification number: H04N19/577 ,  H04N19/132 ,  H04N19/172 ,  H04N19/176

Abstract: In some embodiments, a video encoder or a video decoder obtains a pair of motion vectors for a current coding block of a video signal with respect to two reference frames. Predictions of the current block are generated using the pair of motion vectors from respective reference frames. The video encoder or video decoder further determine an optical flow for the current coding block based on samples values in the predictions. One component of the optical flow is determined based on the other component of the optical flow. Bi-predictive optical flow (BPOF) can be performed on the current coding block using the determined optical flow.