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：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：US12212777B2

公开(公告)日：2025-01-28

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

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.

公开(公告)号：US12206860B2

公开(公告)日：2025-01-21

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

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：US12015762B2

公开(公告)日：2024-06-18

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 ,  H04N19/176 ,  H04N19/46

CPC classification number: H04N19/105 ,  H04N19/132 ,  H04N19/137 ,  H04N19/159 ,  H04N19/176 ,  H04N19/46

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：US11968387B2

公开(公告)日：2024-04-23

申请号：US17467785

申请日：2021-09-07

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Sagar Kotecha ,  Jeeva Raj A

IPC: H04N19/513 ,  H04N19/107 ,  H04N19/132 ,  H04N19/139 ,  H04N19/176

CPC classification number: H04N19/513 ,  H04N19/107 ,  H04N19/132 ,  H04N19/139 ,  H04N19/176

Abstract: A bidirectional optical flowing prediction method includes obtaining an initial motion vector pair for a current block, obtaining a forward and a backward prediction block according to the forward motion vector and a backward prediction block according to the initial motion vector pair, and calculating gradient parameters for a current sample in the current block. The method further includes obtaining at least two sample optical flow parameters, including a first parameter and a second parameter, for the current sample based on the gradient parameters, obtaining block optical flow parameters based on sample optical flow parameters of samples in the current block, and obtaining a prediction value of the current block. One of the block optical flow parameters is obtained by multiplying the first parameter and a sign function of the second parameter, and the sign function is a piecewise function with at least three subintervals.

公开(公告)号：US11889109B2

公开(公告)日：2024-01-30

申请号：US17478184

申请日：2021-09-17

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.

公开(公告)号：US11563948B2

公开(公告)日：2023-01-24

申请号：US17249771

申请日：2021-03-12

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/137 ,  H04N19/105 ,  H04N19/159 ,  H04N19/176 ,  H04N19/52 ,  H04N19/70

Abstract: A method for inter-prediction of a current image block in a current picture of a video is provided. The method includes determining whether a first temporal distance (such as TD0) is equal to a second temporal distance (such as TD1), wherein the first temporal distance is represented in terms of a difference between a picture order count value of the current picture and a picture order count value of a first reference picture; and the second temporal distance is represented in terms of a difference between a picture order count value of a second reference picture and the picture order count value of the current picture; and performing no motion vector refinement (DMVR) procedure when it is determined that the first temporal distance (TD0) is not equal to the second temporal distance (TD1). Thus the DMVR procedure is restricted to only the image block with equal-distance references.

公开(公告)号：US11490096B2

公开(公告)日：2022-11-01

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 ,  H04N19/176 ,  H04N19/513

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.