公开(公告)号：US20210409712A1

公开(公告)日：2021-12-30

申请号：US17129504

申请日：2020-12-21

Applicant: BEIJING BAIDU NETCOM SCIENCE AND TECHNOLOGY CO., LTD.

Inventor： Ke LIN ,  Wenpeng DING

IPC: H04N19/124 ,  H04N19/177 ,  H04N19/176 ,  H04N19/136

Abstract: The present disclosure provides a method and an apparatus for coding a video, a device and a medium. An estimated quantization parameter of a target picture in a target GOP is determined. An inter-picture change degree of the target GOP is determined. A propagation ratio of a target picture block to a reference picture block in the target picture is determined based on the estimated quantization parameter of the target picture and the inter-picture change degree. The video is coded based on the propagation ratio.

公开(公告)号：US20210337205A1

公开(公告)日：2021-10-28

申请号：US17353415

申请日：2021-06-21

Applicant: Beijing Baidu Netcom Science and Technology Co., Ltd.

Inventor： Ke LIN ,  Wenpeng DING

IPC: H04N19/124 ,  H04N19/13 ,  H04N19/132 ,  H04N19/176

Abstract: A method and apparatus for adjusting a quantization parameter for adaptive quantization are provided. An implementation of the method may include: acquiring at least one pixel block corresponding to a to-be-compressed image and an initial quantization parameter adjustment value corresponding to the pixel block, the initial quantization parameter adjustment value being generated based on an image objective quality evaluation index; determining a just noticeable difference, JND, threshold corresponding to each pixel point in the at least one pixel block; determining a block JND threshold corresponding to each pixel block, based on the JND threshold corresponding to each pixel point in the at least one pixel block; and adjusting the corresponding initial quantization parameter adjustment value based on the block JND threshold to generate an adjusted quantization parameter adjustment value corresponding to the at least one pixel block.

公开(公告)号：US20210297664A1

公开(公告)日：2021-09-23

申请号：US17338259

申请日：2021-06-03

Applicant: BEIJING BAIDU NETCOM SCIENCE AND TECHNOLOGY CO., LTD.

Inventor： Jiaojiao ZHANG ,  Wenpeng DING

IPC: H04N19/11 ,  H04N19/147 ,  H04N19/159 ,  H04N19/176

Abstract: A set of rough prediction modes including a MPM subset is determined for a code block during image encoding. A first prediction mode having a mode cost less than a first threshold is selected from the set of rough prediction modes, and a second prediction mode having a mode cost less than a second threshold is selected from the MPM subset. A candidate mode subset is determined based on mode types of prediction modes contained in the set of rough prediction modes and a ranking result of mode costs of the prediction modes, when the mode cost of the first prediction mode is different from the mode cost of the second prediction mode. A target prediction mode is determined for the code block from the candidate mode subset. The code block is encoded with the target prediction mode.