公开(公告)号：US11818372B2

公开(公告)日：2023-11-14

申请号：US18096425

申请日：2023-01-12

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 ,  H04N19/172 ,  H04N19/30 ,  H04N19/46 ,  H04N19/70

CPC classification number: H04N19/31 ,  H04N19/172 ,  H04N19/187 ,  H04N19/30 ,  H04N19/46 ,  H04N19/70

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：US11663702B2

公开(公告)日：2023-05-30

申请号：US17415674

申请日：2019-12-10

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Neeraj J. Gadgil ,  Qing Song ,  Guan-Ming Su

IPC: G06T5/00 ,  H04N19/86 ,  G06T5/20

CPC classification number: G06T5/002 ,  G06T5/20 ,  H04N19/86 ,  G06T2207/20012

Abstract: Methods and systems for reducing banding artifacts when displaying images are described. Identified image bands are filtered using an adaptive sparse finite response filter, where the tap-distance in the sparse filter is adapted according to an estimated width of each image band. Image debanding may be performed across multiple pixel orientations, such as rows, columns, a 45-degree angle, or a −45-degree angle. Given a threshold to decide whether sparse filtering needs to be performed or not, an iterative debanding process is also proposed.

公开(公告)号：US20230039038A1

公开(公告)日：2023-02-09

申请号：US17780895

申请日：2020-11-25

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Harshad Kadu ,  Ji Qi ,  Guan-Ming Su

IPC: H04N19/186 ,  H04N19/146

Abstract: Given an input image in a high dynamic range (HDR) which is mapped to a second image in a second dynamic range using a reshaping function, to improve coding efficiency, a reshaping function generator may adjust the codeword range of the HDR input under certain criteria, such as for noisy HDR images with a relatively-small codeword range. An example of generating a scaler for adjusting the HDR codeword range based on the original codeword range and a metric of the percentage of edge-points in the HDR image is provided. The adjusted reshaping function allows for more efficient rate control during the compression of reshaped images.

公开(公告)号：US11272213B2

公开(公告)日：2022-03-08

申请号：US16649604

申请日：2018-09-21

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Guan-Ming Su ,  Neeraj J. Gadgil ,  Tao Chen ,  Sheng Qu

IPC: H04N19/70 ,  H04N19/132 ,  H04N19/68 ,  H04N19/89

Abstract: Sequence-level parameters are generated for an image frame sequence including sequence-level indicators for indicating metadata types present for each image frame in the sequence of image frames. Frame-present parameters are generated for a specific image frame in the sequence including frame-present indicators corresponding to the metadata types as indicated in the sequence-level parameters. The frame-present indicators identify first metadata types for which metadata parameter values are to be encoded in a coded bitstream as metadata payloads. The image frame sequence, the sequence-level parameters, the frame-present parameters and the metadata payloads are encoded in the coded bitstream. A recipient device can generate, from the specific image frame based partly on the metadata parameter values determined for the first metadata types, a target display image for a target display.

公开(公告)号：US10778983B2

公开(公告)日：2020-09-15

申请号：US15763039

申请日：2016-09-22

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Qian Chen ,  Guan-Ming Su

IPC: H04N19/154 ,  H04N19/115 ,  H04N19/169 ,  H04N19/34 ,  H04N19/86 ,  H04N19/179 ,  H04N19/30 ,  H04N19/124 ,  H04N19/172 ,  H04N19/136 ,  H04L29/06

Abstract: For each content-mapped frame of a scene, it is determined whether the content mapped frame is susceptible to object fragmentation with respect to texture in a homogeneous region based on statistical values derived from the content-mapped image and a source image mapped into the content-mapped image. The homogeneous region is a region of consistent texture in the source image. Based on a count of content-mapped frames susceptible to object fragmentation in homogeneous region, it is determined whether the scene is susceptible to object fragmentation in homogeneous region. If so, an upper limit for mapped codewords for a prediction function for predicting codewords of a predicted image from the mapped codewords in the content-mapped image is adjusted. Mapped codewords above the upper limit are clipped to the upper limit.

公开(公告)号：US10609372B2

公开(公告)日：2020-03-31

申请号：US16139965

申请日：2018-09-24

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Guan-Ming Su ,  Amin Kheradmand ,  Navaneeth Kamballur Kottayil

IPC: H04N19/176 ,  H04N19/14 ,  H04N19/124 ,  H04N19/36 ,  H04N19/37 ,  H04N19/11 ,  H04N19/117

Abstract: Input minimal noise levels of are computed over input codeword bins based on image content in input images of an input bit depth. The minimal noise levels are adjusted to generate approximated minimal noise levels of a higher bit depth. The approximated minimal noise levels are used to generate per-bin bit depths over the input codeword bins. The input codeword bins are classified into first codeword bins that have relatively high risks of banding artifacts and some other input codeword bins that have relatively low or zero risks of banding artifacts based on the per-bin bit depths. Portions of bit depths from the other input codeword bins are moved to the first input codeword bins to generate modified per-bin bit depths. A forward reshaping function constructed from the modified per-bin bit depths is used to reshape the input images into reshaped images used to generate output images.

公开(公告)号：US10575005B2

公开(公告)日：2020-02-25

申请号：US15745647

申请日：2016-07-20

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Guan-Ming Su ,  Sheng Qu ,  Samir N. Hulyalkar ,  David Brooks

IPC: H04N19/33 ,  H04N19/59

Abstract: In a method to code and transmit scalable HDR video signals, HDR signals are processed and encoded in the IPT-PQ color space to generate a base layer at reduced spatial resolution and/or dynamic range, and an enhancement layer with a residual signal. A signal reshaping block before the base layer encoder allows for improved coding of HDR signals using a reduced bit depth. A decoder can use a BL decoder and backward reshaping to generate a decoded BL HDR signal at a reduced dynamic range and/or spatial resolution, or it can combine the decoded BL HDR signal and the EL stream to generate a decoded HDR signal at full dynamic range and full resolution.

公开(公告)号：US10542269B2

公开(公告)日：2020-01-21

申请号：US15773525

申请日：2016-12-07

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Harshad Kadu ,  Guan-Ming Su ,  Hanyang Sun

IPC: H04N19/44 ,  G06T5/00 ,  H04N19/186 ,  H04N19/82

Abstract: In a method to reconstruct a high dynamic range video signal, a decoder receives parameters in the input bitstream to generate a prediction function. Using the prediction function, it generates a first set of nodes for a first prediction lookup table, wherein each node is characterized by an input node value and an output node value.Then, it modifies the output node values of one or more of the first set of nodes to generate a second set of nodes for a second prediction lookup table, and generates output prediction values using the second lookup table. Low-complexity methods to modify the output node value of a current node in the first set of nodes based on computing modified slopes between the current node and nodes surrounding the current node are presented.

公开(公告)号：US10419762B2

公开(公告)日：2019-09-17

申请号：US15555047

申请日：2016-03-01

Applicant: Dolby Laboratories Licensing Corporation ,  DOLBY INTERNATIONAL AB

Inventor： Jan Froehlich ,  Guan-Ming Su ,  Robin Atkins ,  Scott Daly ,  Jon Scott Miller

IPC: H04N19/124 ,  H04N19/136 ,  H04N19/98 ,  H04N19/117 ,  H04N19/132 ,  H04N19/156 ,  H04N19/182 ,  H04N19/154

Abstract: A content-adaptive quantizer processor receives an input image with an input bit depth. A noise-mask generation process is applied to the input image to generate a noise mask image which characterizes each pixel in the input image in terms of its perceptual relevance in masking quantization noise. A noise mask histogram is generated based on the input image and the noise mask image. A masking-noise level to bit-depth function is applied to the noise mask histogram to generate minimal bit depth values for each bin in the noise mask histogram. A codeword mapping function is generated based on the input bit depth, a target bit depth, and the minimal bit depth values. The codeword mapping function is applied to the input image to generate an output image in the target bit depth.

公开(公告)号：US20190281325A1

公开(公告)日：2019-09-12

申请号：US16294875

申请日：2019-03-06

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Qing Song ,  Harshad Kadu ,  Guan-Ming Su

IPC: H04N19/98 ,  H04N19/186 ,  H04N19/14 ,  H04N19/169

Abstract: A standard dynamic range (SDR) image is received. Composer metadata of the first level through the N-th level is generated. Composer metadata of the j-th level is generated based on the composer metadata of the first level through (j−1)-th level. The composer metadata of the first level through the composer metadata of the j-th level is to be used for mapping the SDR image to the j-th target image specifically optimized for the j-th reference target display. The SDR image is encoded with the composer metadata of the first level through the k-th level in an output SDR video signal, where 1