Patents by Inventor Hok Kwan CHEUNG

Hok Kwan CHEUNG has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10789696
    Abstract: The present disclosure relates to a method for image patch selection for training a neural network for image quality assessment. The method includes receiving an input image and extracting one or more image patches from the input image. The moment of the extracted image patches is measured. There is a decision to accept or decline the extracted image patches according to the measured moment. Additional image patches are extracted until a minimum number, Nmin, of extracted image patches are accepted. Alternatively, selection criteria are adjusted until the minimum number of extracted image patches are accepted. The selected image patches are input into a neural network with a corresponding image quality value of the input image, and the neural network is trained with the image patches and image quality value. Also provided is a method for image quality assessment using a neural network trained as set forth above.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: September 29, 2020
    Assignee: TFI DIGITAL MEDIA LIMITED
    Inventors: Lai Man Po, Mengyang Liu, Yiu Fai Yuen, Yuming Li, Xuyuan Xu, Chang Zhou, Hon Wah Wong, Kin Wai Lau, Hon Tung Luk, Hok Kwan Cheung
  • Patent number: 10694199
    Abstract: A method for distributed video transcoding consists of segmentation process 101, transcoding process 102 and combining process 103. The said segmentation process consists of time division based segmentation 201, spatial division based segmentation 301 and hybrid segmentation 401. The source media is segmented into a number of media segments. These segments are distributed to different processing units 501. Each processing units consists of source reception unit 502, segmentation unit 503, transcoding unit 504, combining unit 505 and finally result storage unit 506 to achieve parallel conversion throughout the process and combined to produce a single transcoded result. The present invention relates to converting an audio-video source media from one format to another within a short duration of time.
    Type: Grant
    Filed: July 27, 2016
    Date of Patent: June 23, 2020
    Inventors: Yiu Fai Yuen, Hok Kwan Cheung, Chi Keung Fong, Yin Sze, Kong Wai Lam
  • Patent number: 10631009
    Abstract: A method based on CTU level rate-distortion optimization for rate control in video coding which can effectively improve the perceptual rate-distortion performance and coding efficiency is provided. Firstly, a perceptual rate-distortion model is established using a divisive normalization framework, which characterizes the relationship between local visual quality and coding bits. Subsequently, the established perceptual rate-distortion model is applied to overall distortion optimization which is transformed into a global optimization problem and solved with convex optimization algorithms to obtain optimal CTU level coding bit allocation.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: April 21, 2020
    Assignee: TFI Digital Media Limited
    Inventors: Mingliang Zhou, Shiqi Wang, Sam Tak Wu Kwong, Chi Keung Fong, Hon Wah Wong, Hon Tung Luk, Hok Kwan Cheung, Yiu Fai Yuen
  • Patent number: 10560696
    Abstract: A machine learning based initial quantization parameter (QP) prediction method, which can effectively optimize RC performance A machine learning framework for initial QP prediction is proposed, where learning labels are built with the criterion of maximizing rate-distortion (RC) performance, which is proved to be much more effective than the QP determination method with the only consideration on sum of the absolute transformed difference (SATD) complexity. Instead of target bits per pixel for intra frame, target bits per pixel for remaining frames is used as sample data to avoid empirically setting intra frame bit allocation, thus improve the prediction accuracy as the real-time updated remaining bits can better reflect the real-time requirements on the level of QPs. In addition, a clipping and decision approach based on the previous initial QP and the target bits per pixel for all remaining frames is proposed, which can help fast QP adaption and quality smoothness.
    Type: Grant
    Filed: June 25, 2018
    Date of Patent: February 11, 2020
    Assignee: TFI DIGITAL MEDIA LIMITED
    Inventors: Wei Gao, Sam Tak Wu Kwong, Chi Keung Fong, Hon Wah Wong, Hon Tung Luk, Hok Kwan Cheung, Yiu Fai Yuen
  • Publication number: 20200029093
    Abstract: A method based on CTU level rate-distortion optimization for rate control in video coding which can effectively improve the perceptual rate-distortion performance and coding efficiency is provided. Firstly, a perceptual rate-distortion model is established using a divisive normalization framework, which characterizes the relationship between local visual quality and coding bits. Subsequently, the established perceptual rate-distortion model is applied to overall distortion optimization which is transformed into a global optimization problem and solved with convex optimization algorithms to obtain optimal CTU level coding bit allocation.
    Type: Application
    Filed: July 17, 2018
    Publication date: January 23, 2020
    Inventors: Mingliang ZHOU, Shiqi WANG, Sam Tak Wu KWONG, Chi Keung FONG, Hon Wah WONG, Hon Tung LUK, Hok Kwan CHEUNG, Yiu Fai YUEN
  • Publication number: 20190394466
    Abstract: A machine learning based initial quantization parameter (QP) prediction method, which can effectively optimize RC performance. A machine learning framework for initial QP prediction is proposed, where learning labels are built with the criterion of maximizing rate-distortion (RC) performance, which is proved to be much more effective than the QP determination method with the only consideration on sum of the absolute transformed difference (SATD) complexity. Instead of target bits per pixel for intra frame, target bits per pixel for remaining frames is used as sample data to avoid empirically setting intra frame bit allocation, thus improve the prediction accuracy as the real-time updated remaining bits can better reflect the real-time requirements on the level of QPs. In addition, a clipping and decision approach based on the previous initial QP and the target bits per pixel for all remaining frames is proposed, which can help fast QP adaption and quality smoothness.
    Type: Application
    Filed: June 25, 2018
    Publication date: December 26, 2019
    Inventors: Wei GAO, Sam Tak Wu KWONG, Chi Keung FONG, Hon Wah WONG, Hon Tung LUK, Hok Kwan CHEUNG, Yiu Fai YUEN
  • Publication number: 20190362484
    Abstract: The present disclosure relates to a method for image patch selection for training a neural network for image quality assessment. The method includes receiving an input image and extracting one or more image patches from the input image. The moment of the extracted image patches is measured. There is a decision to accept or decline the extracted image patches according to the measured moment. Additional image patches are extracted until a minimum number, Nmin, of extracted image patches are accepted. Alternatively, selection criteria are adjusted until the minimum number of extracted image patches are accepted. The selected image patches are input into a neural network with a corresponding image quality value of the input image, and the neural network is trained with the image patches and image quality value. Also provided is a method for image quality assessment using a neural network trained as set forth above.
    Type: Application
    Filed: May 24, 2018
    Publication date: November 28, 2019
    Inventors: Lai Man PO, Mengyang LIU, Yiu Fai YUEN, Yuming LI, Xuyuan XU, Chang ZHOU, Hon Wah WONG, Kin Wai LAU, Hon Tung LUK, Hok Kwan CHEUNG
  • Patent number: 10447895
    Abstract: An intelligent method and system for expanding and enhancing the color content of video or image to a wider color gamut to make the displayed video or image more pleasing while certain important and sensitive colors such as skin colors are preserved to avoid the perception of visually unnatural image or video artifacts. With the implementation of such method and system, the merits of the wide color gamut display can be fully utilized to provide videos and images of high visual quality.
    Type: Grant
    Filed: March 27, 2018
    Date of Patent: October 15, 2019
    Assignee: TFI Digital Media Limited
    Inventors: Hon Wah Wong, Hon Tung Luk, Chi Keung Fong, Yin Sze, Hok Kwan Cheung, Yiu Fai Yuen
  • Patent number: 10445865
    Abstract: A method and apparatus for converting a standard dynamic range (SDR) video to a high dynamic range (HDR) video. The conversion is adaptive and takes both spatial and temporal information of a current frame and previous frames into consideration such that the majority of pixels falls into the most sensitive regions of human eyes in the target dynamic range, while at the same time, the continuity of luminance is maintained in temporal domain to prevent flickering.
    Type: Grant
    Filed: March 27, 2018
    Date of Patent: October 15, 2019
    Assignee: TFI DIGITAL MEDIA LIMITED
    Inventors: Hon Wah Wong, Hon Tung Luk, Chi Keung Fong, Yin Sze, Hok Kwan Cheung, Yiu Fai Yuen
  • Publication number: 20190306377
    Abstract: An intelligent method and system for expanding and enhancing the color content of video or image to a wider color gamut to make the displayed video or image more pleasing while certain important and sensitive colors such as skin colors are preserved to avoid the perception of visually unnatural image or video artifacts. With the implementation of such method and system, the merits of the wide color gamut display can be fully utilized to provide videos and images of high visual quality.
    Type: Application
    Filed: March 27, 2018
    Publication date: October 3, 2019
    Inventors: Hon Wah Wong, Hon Tung Luk, Chi Keung Fong, Yin Sze, Hok Kwan Cheung, Yiu Fai Yuen
  • Publication number: 20190304072
    Abstract: A method and apparatus for converting a standard dynamic range (SDR) video to a high dynamic range (HDR) video. The conversion is adaptive and takes both spatial and temporal information of a current frame and previous frames into consideration such that the majority of pixels falls into the most sensitive regions of human eyes in the target dynamic range, while at the same time, the continuity of luminance is maintained in temporal domain to prevent flickering.
    Type: Application
    Filed: March 27, 2018
    Publication date: October 3, 2019
    Inventors: Hon Wah Wong, Hon Tung Luk, Chi Keung Fong, Yin Sze, Hok Kwan Cheung, Yiu Fai Yuen
  • Publication number: 20170094290
    Abstract: A method for distributed video transcoding consists of segmentation process 101, transcoding process 102 and combining process 103. The said segmentation process consists of time division based segmentation 201, spatial division based segmentation 301 and hybrid segmentation 401. The source media is segmented into a number of media segments. These segments are distributed to different processing units 501. Each processing units consists of source reception unit 502, segmentation unit 503, transcoding unit 504, combining unit 505 and finally result storage unit 506 to achieve parallel conversion throughout the process and combined to produce a single transcoded result. The present invention relates to converting an audio-video source media from one format to another within a short duration of time.
    Type: Application
    Filed: July 27, 2016
    Publication date: March 30, 2017
    Inventors: Yiu Fai YUEN, Hok Kwan CHEUNG, Chi Keung FONG, Yin SZE, Kong Wai LAM