公开(公告)号：US11277646B2

公开(公告)日：2022-03-15

申请号：US17282523

申请日：2019-10-02

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Qing Song ,  Neeraj J. Gadgil ,  Guan-Ming Su ,  Peng Yin ,  Arun Raj

IPC: H04N19/86 ,  H04N19/182 ,  H04N19/189 ,  H04N19/117

Abstract: Methods and systems for reducing banding artifacts when displaying high-dynamic-range images reconstructed from coded reshaped images are described. Given an input image in a high dynamic range (HDR) which is mapped to a second image in a second dynamic range, banding artifacts in a reconstructed HDR image generated using the second image are reduced by a) in darks and mid-tone regions of the input image, adding noise to the input image before being mapped to the second image, and b) in highlights regions of the input image, modifying an input backward reshaping function, wherein the modified backward reshaping function will be used by a decoder to map a decoded version of the second image to the reconstructed HDR image. An example noise generation technique using simulated film-grain noise is provided.

公开(公告)号：US12301848B2

公开(公告)日：2025-05-13

申请号：US18020015

申请日：2021-08-05

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Neeraj J. Gadgil ,  Guan-Ming Su ,  Harshad Kadu

IPC: H04N19/36 ,  H04N19/132 ,  H04N19/186 ,  H04N19/46

Abstract: A forward reshaping mapping is generated to map a source image to a corresponding forward reshaped image of a lower dynamic range. The source image is spatially downsampled to generate a resized image into which noise is injected to generate a noise injected image. The forward reshaping mapping is applied to map the noise injected image to generate a noise embedded image of the lower dynamic range. A video signal is encoded with the noise embedded image and delivered to a recipient device for the recipient device to render a display image generated from the noise embedded image.

公开(公告)号：US12206907B2

公开(公告)日：2025-01-21

申请号：US18029901

申请日：2021-10-01

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Tsung-Wei Huang ,  Guan-Ming Su ,  Neeraj J. Gadgil

IPC: H04N23/741 ,  G06T5/20 ,  G06T5/92 ,  G06T5/94 ,  H04N19/117 ,  H04N19/169 ,  H04N19/186 ,  H04N19/80 ,  H04N19/85

Abstract: A global index value is generated for selecting a global reshaping function for an input image of a relatively low dynamic range using luma codewords in the input image. Image filtering is applied to the input image to generate a filtered image. The filtered values of the filtered image provide a measure of local brightness levels in the input image. Local index values are generated for selecting specific local reshaping functions for the input image using the global index value and the filtered values of the filtered image. A reshaped image of a relatively high dynamic range is generated by reshaping the input image with the specific local reshaping functions selected using the local index values.

公开(公告)号：US12190587B2

公开(公告)日：2025-01-07

申请号：US18044771

申请日：2021-09-17

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Harshad Kadu ,  Guan-Ming Su ,  Neeraj J. Gadgil ,  Tsung-Wei Huang

IPC: G06V20/40 ,  G06T5/40 ,  H04N19/142 ,  H04N19/192 ,  H04N19/98

Abstract: In a cloud-based system for encoding high dynamic range (HDR) video, each node receives a video segment and bumper frames. Each segment is subdivided into primary scenes and secondary scenes to derive scene-based forward reshaping functions that minimize the amount of reshaping-related metadata when coding the video segment, while maintaining temporal continuity among scenes processed by multiple nodes. Methods to generate scene-based forward and backward reshaping functions to optimize video coding and improve the coding efficiency of reshaping-related metadata are also examined.

公开(公告)号：US20250069200A1

公开(公告)日：2025-02-27

申请号：US18718142

申请日：2022-12-07

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Dae Yeol Lee ,  Neeraj J. Gadgil ,  Guan-Ming Su

IPC: G06T5/70 ,  G06T7/20

Abstract: Novel methods and systems are described for providing interactive motion blur on an image by motion inputs from movements of the mobile device displaying the image. The device can process the motion blur by modules providing motion blur parameter estimation, blur application, and image composition based on metadata and a baseline image from the encoder. A pre-loaded filter bank can provide blur kernels for blur application.

公开(公告)号：US11962760B2

公开(公告)日：2024-04-16

申请号：US17764394

申请日：2020-09-29

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

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

IPC: H04N19/105 ,  H04N19/132 ,  H04N19/154 ,  H04N19/196 ,  H04N19/436

CPC classification number: H04N19/105 ,  H04N19/132 ,  H04N19/154 ,  H04N19/196 ,  H04N19/436

Abstract: A set of tensor-product B-Spline (TPB) basis functions is determined. A set of selected TPB prediction parameters to be used with the set of TPB basis functions for generating predicted image data in mapped images from source image data in source images of a source color grade is generated. The set of selected TPB prediction parameters is generated by minimizing differences between the predicted image data in the mapped images and reference image data in reference images of a reference color grade. The reference images correspond to the source images and depict same visual content as depicted by the source images. The set of selected TPB prediction parameters is encoded in a video signal as a part of image metadata along with the source image data in the source images. The mapped images are caused to be reconstructed and rendered with a recipient device of the video signal.

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：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：US11341624B2

公开(公告)日：2022-05-24

申请号：US17267369

申请日：2019-08-07

Applicant: Dolby Laboratories Licensing Corporation

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

IPC: G06T5/00

Abstract: Methods and systems for reducing banding artifacts when displaying high-dynamic-range images are described. Given an input image in a first dynamic range, and an input backward reshaping function mapping codewords from the first dynamic range to a second dynamic range, wherein the second dynamic range is equal or higher than the first dynamic range, statistical data based on the input image and the input backward reshaping function are generated to estimate the risk of banding artifacts in a target image in the second dynamic range generated by applying the input backward reshaping function to the input image. Separate banding alleviation algorithms are applied in the darks and highlights parts of the first dynamic range to generate a modified backward reshaping function, which when applied to the input image to generate the target image eliminates or reduces banding in the target image.

公开(公告)号：US11310537B2

公开(公告)日：2022-04-19

申请号：US16975096

申请日：2019-02-28

Applicant: DOLBY LABORATORIES LICENSING CORPORATION

Inventor： Neeraj J. Gadgil ,  Guan-Ming Su

IPC: H04N19/98 ,  H04N19/132 ,  H04N19/182 ,  H04N19/186 ,  G06F1/03

Abstract: In some embodiments, an encoder device is disclosed to receive an input video stream containing images in a first dynamic range including a first image. The device receives a second image representing the first image. The device obtains statistical data for the first and the second images. The device determines, at a first time delay, a scene cut data from the input video stream and storing the scene cut data in a first sliding window. The device determines, at a second time delay, a first smoothing mapping function based on a second sliding window and the determined scene cut data. The device determines, at a third time delay, a second smoothing mapping function based on a third sliding window and the determined scene cut data. The device generates, at the third time delay, a composer metadata for the first image based on the first and second smoothing mapping functions.