Patents by Inventor Wai Kuen Cham
Wai Kuen Cham 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: 8719321Abstract: The LLMICT transform matrices are orthogonal, hence their inverses are their transpose. The LLMICT transform matrices are integer matrices, which can be implemented with high precision eliminating the drift error in video coding. The fast algorithms for the LLMICT transform are found, thus allowing a lower requirement on computation hardware. The LLMICT is also found to have high transform coding gain due to its similarity to the DCT.Type: GrantFiled: December 11, 2011Date of Patent: May 6, 2014Assignee: Hong Kong Applied Science and Technology Research Institute Company LimitedInventors: Chi Keung Fong, Wai-Kuen Cham
-
Patent number: 8630356Abstract: Disclosed are a filter and a method to improve the objective and subjective video coding performance The filter comprises: a parameter estimation unit configured to determine means and variances from a pilot frame; a filter unit configured to receive quantized residual coefficients in video coding process and restore coefficients from the quantized residual coefficients and the determined means and variances; an inverse ICT unit configured to apply an inverse ICT to the restored coefficients to obtain a filtered frame; a rate-distortion optimization unit configured to determine a quadtree block partition index; and an adaptive block selection unit configured to select final blocks according to quadtree block partition index, the final blocks being utilized to form the filtered frame.Type: GrantFiled: January 4, 2011Date of Patent: January 14, 2014Assignee: The Chinese University of Hong KongInventors: Renqi Zhang, Wai Kuen Cham
-
Patent number: 8582910Abstract: Methods and apparatus for editing an image having focused and defocused objects are provided in the present application. According to an embodiment, the method comprises: determining blurriness of edge pixels in the image; propagating the determined blurriness to non-edge pixels adjacent to each of the edge pixels so as to determine blurriness of the non-edge pixels; estimating a focus map based on the blurriness of the edge pixels and the non-edge pixels to identify the defocused objects and the focused objects; and refocusing the defocused objects based on the focus map or defocusing at least one of the defocused objects and the focused objects.Type: GrantFiled: October 1, 2010Date of Patent: November 12, 2013Assignee: The Chinese University of Hong KongInventors: Wei Zhang, Wai Kuen Cham
-
Patent number: 8559511Abstract: The present invention relates to method and apparatus for video coding by ABT-based just noticeable difference (JND). For building the just noticeable difference model, spatial content information (SCI) is used to represent the spatial appearance similarity between one macroblock and its sub-blocks and the motion characteristic distance (MCD) is used to represent the motion characteristics similarity between one macroblock and its sub-blocks. For intra frames, the balance strategy based on the obtained SCI of the macroblock is used to generate the ABT-based JND model. For inter frames, the balanced strategy based on the obtained SCI and MCD of the macroblock is used to generate the ABT-based JND model. Using the ABT-based JND model, the residual coefficients for each block in a frame is filtered to obtain a reduced set of residual coefficients for transmission without degradation in visual quality.Type: GrantFiled: March 30, 2010Date of Patent: October 15, 2013Assignee: Hong Kong Applied Science and Technology Research Institute Company LimitedInventors: King Ngi Ngan, Lin Ma, Wai-Kuen Cham, Yu Liu
-
Patent number: 8483281Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including transform of encoding and decoding of image and video signals and generation of an order-2N transform W from an order-N transform T in the field of image and video coding. For example, a retrieving unit is configured to retrieve an order-N transform T, where N is an integer; a deriving unit is configured to derive an order-2N transform W from the retrieved order-N transform T, and a transforming unit configured to generate an order-2N data Z using the derived transform W.Type: GrantFiled: November 30, 2011Date of Patent: July 9, 2013Assignee: The Chinese University of Hong KongInventor: Wai Kuen Cham
-
Publication number: 20130151575Abstract: The LLMICT transform matrices are orthogonal, hence their inverses are their transpose. The LLMICT transform matrices are integer matrices, which can be implemented with high precision eliminating the drift error in video coding. The fast algorithms for the LLMICT transform are found, thus allowing a lower requirement on computation hardware. The LLMICT is also found to have high transform coding gain due to its similarity to the DCT.Type: ApplicationFiled: December 11, 2011Publication date: June 13, 2013Applicant: Hong Kong Applied Science and Technology Research Institute Company LimitedInventors: Chi Keung Fong, Wai-Kuen Cham
-
Patent number: 8451896Abstract: The invention relates to adjusting the quantization parameter in digital video coding. A shift value (QP Shift) is used to adjust the quantization parameter. The shift value is determined in a determining step 101. The video nature is determined and compared with a threshold in a comparing step 102 to adjust the shift value adaptively according to the frame type in an adjusting step 103. The shift value shifts the quantization parameter in a shifting step 104.Type: GrantFiled: October 19, 2009Date of Patent: May 28, 2013Assignee: Hong Kong Applied Science and Technology Research Institute Company LimitedInventors: Chi Keung Fong, Wai Kuen Cham, Ka Man Cheng, Yu Liu
-
Patent number: 8255445Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including apparatus, systems and techniques for deriving an order-16 integer transform from an order-8 integer transform in image and video coding. In some implementations, eight additions and eight subtractions are used to assign the data elements to be transformed to an intermediate matrix; and then two fast algorithms for the computation of the order-8 transform may be applied to the first 8 vectors of the intermediate matrix, and the last 8 vectors of the intermediate matrix, respectively. The derived order-16 integer transform tends to produce small magnitude and high frequency transformed coefficients, and thus achieve high compressibility.Type: GrantFiled: April 9, 2008Date of Patent: August 28, 2012Assignee: The Chinese University of Hong KongInventors: Wai Kuen Cham, Chi Keung Fong
-
Patent number: 8228983Abstract: The invention is used in video coding. Systems, apparatuses and methods for processing an order-16 integer transform from an order-8 transform are provided. The order-16 transform method involves expanding an order-8 transform by generating an order-16 integer matrix and a scaling matrix.Type: GrantFiled: December 4, 2007Date of Patent: July 24, 2012Assignees: Hong Kong Applied Science and Technology Research, Institute Company LimitedInventors: Wai-Kuen Cham, Chi Keung Fong, Jie Dong, King Ngi Ngan, Hoi Ming Wong, Lu Wang, Yan Huo, Thomas H. Y. Pun
-
Publication number: 20120170668Abstract: Disclosed are a filter and a method to improve the objective and subjective video coding performance The filter comprises: a parameter estimation unit configured to determine means and variances from a pilot frame; a filter unit configured to receive quantized residual coefficients in video coding process and restore coefficients from the quantized residual coefficients and the determined means and variances; an inverse ICT unit configured to apply an inverse ICT to the restored coefficients to obtain a filtered frame; a rate-distortion optimization unit configured to determine a quadtree block partition index; and an adaptive block selection unit configured to select final blocks according to quadtree block partition index, the final blocks being utilized to form the filtered frame.Type: ApplicationFiled: January 4, 2011Publication date: July 5, 2012Applicant: THE CHINESE UNIVERSITY OF HONG KONGInventors: Renqi Zhang, Wai Kuen Cham
-
Patent number: 8175165Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including an order-16 integer transform from a Microsoft Media Video order-8 integer transform with a high energy-packing ability and an improved data compression in the field of image and video coding. For example, a method and an apparatus are provided for deriving an order-16 integer transform from an order-8 integer transform in the standard transform of Microsoft Media Video. Eight additions and eight subtractions are used to assign the data elements to be transformed to an intermediate matrix; and then two fast algorithms for the computation of the order-8 transform may be applied to the first 8 vectors of the intermediate matrix, and the last 8 vectors of the intermediate matrix, respectively. The derived order-16 integer transform tends to produce small magnitude and high frequency transformed coefficients, and thus achieve high compressibility.Type: GrantFiled: April 15, 2008Date of Patent: May 8, 2012Assignee: The Chinese University of Hong KongInventors: Wai Kuen Cham, Chi Keung Fong
-
Publication number: 20120069908Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including transform of encoding and decoding of image and video signals and generation of an order-2N transform W from an order-N transform T in the field of image and video coding. For example, a retrieving unit is configured to retrieve an order-N transform T, where N is an integer; a deriving unit is configured to derive an order-2N transform W from the retrieved order-N transform T, and a transforming unit configured to generate an order-2N data Z using the derived transform W.Type: ApplicationFiled: November 30, 2011Publication date: March 22, 2012Applicant: THE CHINESE UNIVERSITY OF HONG KONGInventor: Wai Kuen Cham
-
Patent number: 8102918Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including transform of encoding and decoding of image and video signals and generation of an order-2N transform W from an order-N transform T in the field of image and video coding. For example, a retrieving unit is configured to retrieve an order-N transform T, where N is an integer; a deriving unit is configured to derive an order-2N transform W from the retrieved order-N transform T, and a transforming unit configured to generate an order-2N data Z using the derived transform W.Type: GrantFiled: April 15, 2008Date of Patent: January 24, 2012Assignee: The Chinese University of Hong KongInventor: Wai Kuen Cham
-
Publication number: 20110243228Abstract: The present invention relates to method and apparatus for video coding by ABT-based just noticeable difference (JND). For building the just noticeable difference model, spatial content information (SCI) is used to represent the spatial appearance similarity between one macroblock and its sub-blocks and the motion characteristic distance (MCD) is used to represent the motion characteristics similarity between one macroblock and its sub-blocks. For intra frames, the balance strategy based on the obtained SCI of the macroblock is used to generate the ABT-based JND model. For inter frames, the balanced strategy based on the obtained SCI and MCD of the macroblock is used to generate the ABT-based JND model. Using the ABT-based JND model, the residual coefficients for each block in a frame is filtered to obtain a reduced set of residual coefficients for transmission without degradation in visual quality.Type: ApplicationFiled: March 30, 2010Publication date: October 6, 2011Applicant: HONG KONG APPLIED SCIENCE AND TECHNOLOGY RESEARCH INSTITUTE COMPANY LIMITEDInventors: King Ngi NGAN, Lin MA, Wai-Kuen CHAM, Yu LIU
-
Publication number: 20110085741Abstract: Methods and apparatus for editing an image having focused and defocused objects are provided in the present application. According to an embodiment, the method comprises: determining blurriness of edge pixels in the image; propagating the determined blurriness to non-edge pixels adjacent to each of the edge pixels so as to determine blurriness of the non-edge pixels; estimating a focus map based on the blurriness of the edge pixels and the non-edge pixels to identify the defocused objects and the focused objects; and refocusing the defocused objects based on the focus map or defocusing at least one of the defocused objects and the focused objects.Type: ApplicationFiled: October 1, 2010Publication date: April 14, 2011Applicant: THE CHINESE UNIVERSITY OF HONG KONGInventors: Wei Zhang, Wai Kuen Cham
-
Publication number: 20090257505Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including transform of encoding and decoding of image and video signals and generation of an order-2N transform W from an order-N transform T in the field of image and video coding. For example, a retrieving unit is configured to retrieve an order-N transform T, where N is an integer; a deriving unit is configured to derive an order-2N transform W from the retrieved order-N transform T, and a transforming unit configured to generate an order-2N data Z using the derived transform W.Type: ApplicationFiled: April 15, 2008Publication date: October 15, 2009Applicant: THE CHINESE UNIVERSITY OF HONG KONGInventor: Wai Kuen Cham
-
Publication number: 20090257504Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including an order-16 integer transform from a Microsoft Media Video order-8 integer transform with a high energy-packing ability and an improved data compression in the field of image and video coding. For example, a method and an apparatus are provided for deriving an order-16 integer transform from an order-8 integer transform in the standard transform of Microsoft Media Video. Eight additions and eight subtractions are used to assign the data elements to be transformed to an intermediate matrix; and then two fast algorithms for the computation of the order-8 transform may be applied to the first 8 vectors of the intermediate matrix, and the last 8 vectors of the intermediate matrix, respectively. The derived order-16 integer transform tends to produce small magnitude and high frequency transformed coefficients, and thus achieve high compressibility.Type: ApplicationFiled: April 15, 2008Publication date: October 15, 2009Applicant: THE CHINESE UNIVERSITY OF HONG KONGInventors: Wai Kuen Cham, Chi Keung Fong
-
Publication number: 20090141796Abstract: The invention is used in video coding. Systems, apparatuses and methods for processing an order-16 integer transform from an order-8 transform are provided. The order-16 transform method involves expanding an order-8 transform by generating an order-16 integer matrix and a scaling matrix.Type: ApplicationFiled: December 4, 2007Publication date: June 4, 2009Applicant: Hong Kong Applied Science and Technology Research Institute Co. Ltd.Inventors: Wai-Kuen Cham, Chi Keung Fong, Jie Dong, King Ngi Ngan, Hoi Ming Wong, Lu Wang, Yan Huo, Thomas H. Y. Pun
-
Publication number: 20090112958Abstract: Apparatus, systems and techniques based on an integer transform for encoding and decoding video or image signals, including apparatus, systems and techniques for deriving an order-16 integer transform from an order-8 integer transform in image and video coding. In some implementations, eight additions and eight subtractions are used to assign the data elements to be transformed to an intermediate matrix; and then two fast algorithms for the computation of the order-8 transform may be applied to the first 8 vectors of the intermediate matrix, and the last 8 vectors of the intermediate matrix, respectively. The derived order-16 integer transform tends to produce small magnitude and high frequency transformed coefficients, and thus achieve high compressibility.Type: ApplicationFiled: April 9, 2008Publication date: April 30, 2009Applicant: THE CHINESE UNIVERSITY OF HONG KONGInventors: Wai Kuen Cham, Chi Keung Fong
-
Publication number: 20080284906Abstract: Disclosed are a device and a method for transforming a first coding coefficients of video signals into a second coding coefficients of the video signals. The device includes a first storing means for storing the first coding coefficients; a second storing means for storing a transform matrix; a multiplication means for multiplying the first coding coefficients by coefficients of the transform matrix; an addition means for adding each of values resulted from the multiplication operation of the multiplication means to form a sum; and a shifting means for shifting the sum to obtain the second coding coefficients. According to the present invention, signals compressed by various transforms may be transformed to each other, so as to make various compression signals compatible. Thus, the signals can be compatible with more standards and are more universal.Type: ApplicationFiled: December 8, 2006Publication date: November 20, 2008Inventors: Wai Kuen Cham, Chi Keung Fong