公开(公告)号：US20220295020A1

公开(公告)日：2022-09-15

申请号：US17630901

申请日：2020-07-27

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Guan-Ming SU ,  Harshad KADU ,  Neeraj J. GADGIL ,  Qing SONG ,  Yoon Yung LEE

IPC: H04N9/04 ,  G06T5/00 ,  G06T5/40 ,  G06T7/90 ,  H04N19/186 ,  H04N19/98

Abstract: A device includes an electronic processor configured to define a first set of sample pixels from a set of sample pixels determined from received video data according to a first electro-optical transfer function (EOTF) in a first color representation of a first color space; convert the first set of sample pixels to a second EOTF via a mapping function, producing a second set of sample pixels according to the second EOTF; convert the first and second set of sample pixels from the first color representation to a second color representation of the first color space; determine a backward reshaping function by repeatedly applying and adjusting a sample backward reshaping function so as to minimize a difference between predicted pixel values obtained by applying the sample backward reshaping function to the pixels of the converted first set and the pixels of the converted second set.

公开(公告)号：US20210150680A1

公开(公告)日：2021-05-20

申请号：US16623326

申请日：2018-06-13

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Neeraj J. GADGIL ,  Guan-Ming SU ,  Tao CHEN ,  Yoon Yung LEE

IPC: G06T5/00 ,  G06T5/40 ,  H04N19/186 ,  H04N19/98

Abstract: A standard dynamic range (SDR) image is received. Composer metadata is generated for mapping the SDR image to an enhanced dynamic range (EDR) image. The composer metadata specifies a backward reshaping mapping that is generated from SDR-EDR image pairs in a training database. The SDR-EDR image pairs comprise SDR images that do not include the SDR image and EDR images that corresponds to the SDR images. The SDR image and the composer metadata are encoded in an output SDR video signal. An EDR display operating with a receiver of the output SDR video signal is caused to render an EDR display image. The EDR display image is derived from a composed EDR image composed from the SDR image based on the composer metadata.

公开(公告)号：US20210092461A1

公开(公告)日：2021-03-25

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 ,  H04N19/186 ,  H04N19/182 ,  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.

公开(公告)号：US20240283975A1

公开(公告)日：2024-08-22

申请号：US18563736

申请日：2022-05-24

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Neeraj J. GADGIL ,  Guan-Ming SU

IPC: H04N19/60 ,  H04N19/172 ,  H04N19/182 ,  H04N19/186

CPC classification number: H04N19/60 ,  H04N19/172 ,  H04N19/182 ,  H04N19/186

Abstract: Methods for encoding and decoding video data. One method includes receiving video data, the video data composed of a plurality of image frames, each image frame including a plurality of pixels. The method includes determining, for each image frame, a rotation matrix, determining, for each image frame, at least one of a scaling factor and an offset factor, and determining, for each image frame, a reshaping function based on one or more values of each of the plurality of pixels. The method includes generating an output image for each image frame by applying the rotation matrix, the reshaping function, and the at least one of the scaling factor and the offset factor to the respective image frame. The rotation matrix is applied to each pixel of the plurality of pixels for the respective image frame before the reshaping function is applied to the respective image frame.

公开(公告)号：US20210368212A1

公开(公告)日：2021-11-25

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 ,  H04N19/117 ,  H04N19/189 ,  H04N19/182

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 dyna mic 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：US20200351524A1

公开(公告)日：2020-11-05

申请号：US16863022

申请日：2020-04-30

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Yoon Yung LEE ,  Neeraj J. GADGIL ,  Guan-Ming SU

IPC: H04N19/98 ,  H04N19/186 ,  H04N19/182

Abstract: A standard dynamic range (SDR) image and a reference backward reshaping mapping are received. The reference backward reshaping mapping comprises a reference luma backward reshaping mapping. A color preservation mapping function is used with inputs generated from the SDR image and the reference backward reshaping mapping to determine luminance increase for SDR luma histogram bins generated based on luma codewords in the SDR image. A modified backward reshaping mapping is generated and comprises a modified luma backward reshaping mapping generated from the reference backward reshaping function based on the luminance increase for the SDR luma histogram bins. The SDR image and the modified backward reshaping mapping are encoded into an SDR video signal.

公开(公告)号：US20240114127A1

公开(公告)日：2024-04-04

申请号：US18264311

申请日：2022-02-10

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Zhaobin ZHANG ,  Neeraj J. GADGIL ,  Guan-Ming SU

IPC: H04N19/105 ,  H04N19/119 ,  H04N19/159 ,  H04N19/176

CPC classification number: H04N19/105 ,  H04N19/119 ,  H04N19/159 ,  H04N19/176

Abstract: Methods, systems, and devices implement intra-prediction for hexagonally-sampled compression and decompression of videos and images having a regular grid of hexagonally-shaped pixels. For encoding, a prediction unit (PU) shape is selected at a sequence level from the group consisting of parallelogram, zigzag-square, hexagonal super-pixel, a rectangular zigzag and an arrow, and the hexagonally-sampled image is divided into regions based on the PU shape. For each region: a prediction mode and a PU size are determined; reference pixels are determined for each predicted pixel in the PU shape based on the prediction mode; a weighted factor is determined for each of the reference pixels based on a distance between the reference pixel and the predicted pixel; and a predicted value of each of the predicted pixels in the PU shape is determined using the corresponding reference pixels and the weighted factors.

公开(公告)号：US20230308667A1

公开(公告)日：2023-09-28

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 ,  H04N19/46 ,  H04N19/132 ,  H04N19/186

CPC classification number: H04N19/36 ,  H04N19/46 ,  H04N19/132 ,  H04N19/186

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：US20230291937A1

公开(公告)日：2023-09-14

申请号：US18002760

申请日：2021-07-08

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Guan-Ming SU ,  Harshad KADU ,  Neeraj J. GADGIL

IPC: H04N19/98 ,  H04N19/192

CPC classification number: H04N19/98 ,  H04N19/192

Abstract: In a cloud-based system for encoding high dynamic range (HDR) video, a computing node is assigned to be a dispatcher node, segmenting the input video into scenes and generating a scene to segment allocation to be used by other computing nodes. The scene to segment allocation process includes one or more iterations with an initial random assignment of scenes to computing nodes, followed by a refined assignment based on optimizing the allocation cost across all the computing 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：US20230005243A1

公开(公告)日：2023-01-05

申请号：US17780279

申请日：2020-12-02

Applicant: Dolby Laboratories Licensing Corporation

Inventor： Amirhossein KHALILIAN-GOURTANI ,  Neeraj J. GADGIL ,  Guan-Ming Su

IPC: G06V10/762 ,  G06V10/764 ,  G06V10/26 ,  G06V10/28 ,  G06V10/34 ,  G06V10/56

Abstract: A method for image segmentation includes (a) clustering, based upon k-means clustering, pixels of an image into first clusters, (b) outputting a cluster map of the first clusters (c) re-clustering the pixels into a new plurality of non-disjoint pixel-clusters, and (d) classifying the non-disjoint pixel-clusters in categories, according to a user-indicated classification. Another method for image segmentation includes (a) forming a graph with each node of the graph corresponding to a first respective non-disjoint pixel-cluster of the image and connected to each terminal of the graph and to all other nodes corresponding to other respective non-disjoint pixel-clusters that, in the image, are within a neighborhood of the first respective non-disjoint pixel-cluster, (b) setting weights of connections of the graph according to a user-indicated classification in categories respectively associated with the terminals, and (c) segmenting the image into the categories by cutting the graph based upon the weights.