公开(公告)号：US11234021B2

公开(公告)日：2022-01-25

申请号：US17203698

申请日：2021-03-16

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Peng Yin ,  Taoran Lu ,  Fangjun Pu ,  Tao Chen ,  Walter J. Husak

IPC: H04N19/70 ,  H04N19/186 ,  H04N19/30 ,  H04N19/85 ,  G06T5/00

Abstract: In a method to improve the coding efficiency of high-dynamic range (HDR) images, a decoder parses sequence processing set (SPS) data from an input coded bitstream to detect that an HDR extension syntax structure is present in the parsed SPS data. It extracts from the HDR extension syntax structure post-processing information that includes one or more of a color space enabled flag, a color enhancement enabled flag, an adaptive reshaping enabled flag, a dynamic range conversion flag, a color correction enabled flag, or an SDR viewable flag. It decodes the input bitstream to generate a preliminary output decoded signal, and generates a second output signal based on the preliminary output signal and the post-processing information.

公开(公告)号：US11172237B2

公开(公告)日：2021-11-09

申请号：US17005333

申请日：2020-08-28

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Taoran Lu ,  Peng Yin ,  Fangjun Pu

IPC: H04N19/98 ,  H04N19/136 ,  H04N19/46 ,  H04N19/33 ,  H04N19/186 ,  H04N19/187 ,  H04N19/172

Abstract: Methods, processes, and systems are presented for inter-layer scaling and mapping to perform dynamic-range scalability in video coding using single-loop video decoders. Two approaches are proposed: a) A mapping function is applied to each of the color components, b) a mapping function is applied to the luma component and luma-based scaling is applied to the chroma components. Both schemes may be combined with existing schemes for in-loop reshaping, such as luma mapping and chroma residual scaling employed in the versatile video codec (VVC).

公开(公告)号：US20210211688A1

公开(公告)日：2021-07-08

申请号：US17212701

申请日：2021-03-25

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Robin Atkins ,  Peng Yin ,  Taoran Lu ,  Fangjun Pu ,  Sean Thomas McCarthy ,  Walter J. Husak ,  Tao Chen ,  Guan-Ming Su

IPC: H04N19/31 ,  H04N19/187

Abstract: Methods and systems for frame rate scalability are described. Support is provided for input and output video sequences with variable frame rate and variable shutter angle across scenes, or for input video sequences with fixed input frame rate and input shutter angle, but allowing a decoder to generate a video output at a different output frame rate and shutter angle than the corresponding input values. Techniques allowing a decoder to decode more computationally-efficiently a specific backward compatible target frame rate and shutter angle among those allowed are also presented.

公开(公告)号：US10999585B2

公开(公告)日：2021-05-04

申请号：US16901911

申请日：2020-06-15

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Robin Atkins ,  Peng Yin ,  Taoran Lu ,  Fangjun Pu ,  Sean Thomas McCarthy ,  Walter J. Husak ,  Tao Chen ,  Guan-Ming Su

IPC: H04N19/31 ,  H04N19/187

Abstract: Methods and systems for frame rate scalability are described. Support is provided for input and output video sequences with variable frame rate and variable shutter angle across scenes, or for input video sequences with fixed input frame rate and input shutter angle, but allowing a decoder to generate a video output at a different output frame rate and shutter angle than the corresponding input values. Techniques allowing a decoder to decode more computationally-efficiently a specific backward compatible target frame rate and shutter angle among those allowed are also presented.

公开(公告)号：US20200304786A1

公开(公告)日：2020-09-24

申请号：US16893454

申请日：2020-06-05

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Peng Yin ,  Taoran Lu ,  Fangjun Pu ,  Tao Chen

IPC: H04N19/117 ,  H04N19/82 ,  H04N19/136

Abstract: Methods, processes, and systems are presented for adaptive loop filtering in coding and decoding high dynamic range (HDR) video. Given an input image block, its luminance information may be used to adapt one or more parameters of adaptive loop filtering and compute gradient and directionality information, activity information, a classification index, and adaptive-loop-filtering coefficients.

公开(公告)号：US10484684B2

公开(公告)日：2019-11-19

申请号：US15564185

申请日：2016-04-19

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Taoran Lu ,  Fangjun Pu ,  Peng Yin ,  Tao Chen

IPC: H04N19/126 ,  H04N9/67 ,  H04N19/85 ,  H04N19/186 ,  G06T5/00

Abstract: In a method to improve the coding efficiency of high-dynamic range images coded in a perceptually quantized IPT color space (IPT-PQ), the values of the chroma components (P/T) of an input signal in IPT-PQ color space are divided by a factor of two before being encoded with standard-based encoders, such as AVC or HEVC; thus better matching the covariance characteristics of YCbCr signals. In addition, the order of the P and T chroma components may be swapped and the sign of the T chroma component may be inverted. Color transformation matrices for efficient forward and backward reshaping in the IPT-PQ color space are provided.