Patents by Inventor Oscar Chi-Lim Au

Oscar Chi-Lim Au 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).

  • Publication number: 20110293012
    Abstract: Provided is sub-block motion estimation that includes a full search with a reduced search area around a motion vector predictor. Also provided are a single (or unified) motion vector predictor and a function similar to a rate-distortion cost function. Also provided is a scanning order that can reduce or substantially eliminated redundant data loading and/or that can achieve different data re-use ratio. Further, provided herein is a reconfigurable multi-resolution motion vector re-use hardware architecture based on a single motion vector predictor and a function similar to a rate-distortion cost function. Further, through utilization of the disclosed aspects, only a small number of past motion vectors are propagated and the disclosed aspects can be reconfigured for video with different spatial resolution.
    Type: Application
    Filed: May 27, 2011
    Publication date: December 1, 2011
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim AU, Xing WEN, Jiang XU
  • Publication number: 20110254847
    Abstract: Systems, methods, and apparatus for sampling images using minimum mean square error subpixel-based down-sampling are presented herein. A partition component can be configured to divide a first array of pixels into two-dimensional (2-D) blocks of pixels. A sampling component can be configured to receive a query from a device including information associated with a display of the device; diagonally down-sample subpixels of a block of the 2-D blocks and generate a second array of pixels based on the down-sampled subpixels and the query. The sampling component can communicate at least a portion of the second array to the device based on the query. The information associated with the display can include a dimension associated with the display. Further, sampling component can be associated with a web browser; and the query can include an internet based query.
    Type: Application
    Filed: June 9, 2011
    Publication date: October 20, 2011
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Lu Fang
  • Publication number: 20110222770
    Abstract: Systems, methods, and apparatus for sampling images using minimum mean square error subpixel-based down-sampling (MMSE-SD) are presented herein. A partition component can receive a first array of pixels, and divide the first array of pixels into two-dimensional (2-D) blocks of pixels. Further, a sampling component can diagonally down-sample subpixels of a block of the 2-D blocks, and generate a second array of pixels based on the down-sampled subpixels. The sampling component can alternately sample subpixels of adjacent pixels of the block in a diagonal direction, and generate the second array of pixels based on the subpixels. A reconstruction component can create a virtual image based on, at least in part, the second array of pixels. A MMSE-SD component can determine an optimal low resolution image based on, at least in part, respective color components of the virtual image and a high resolution image associated with the first array of pixels.
    Type: Application
    Filed: March 9, 2011
    Publication date: September 15, 2011
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Lu Fang
  • Patent number: 7986441
    Abstract: System and methodologies are provided herein for low-distortion image watermarking. Parity relationships between multiple pixels and/or regions of an image can be leveraged as described herein to reduce the amount of toggling required to embed a watermark in an image, thereby increasing watermark efficiency and reducing visual artifacts introduced in a watermarked image. Various algorithms for leveraging parity relationships are described herein, including a Block-Overlapping Parity Check (BOPC) algorithm, a Champagne Pyramid Parity Check (CPPC) algorithm, and a Tree-Based Parity Check (TBPC) algorithm.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: July 26, 2011
    Assignee: Wong Technologies L.L.C.
    Inventors: Oscar Chi Lim Au, Richard Yuk Ming Li
  • Patent number: 7970224
    Abstract: A method and an apparatus relates to examining respective collections of coefficients out of a plurality of collections of coefficients according to a global coding order of the plurality of collections of coefficients, the respective collections of coefficients having respective priority levels as well as respective pluralities of coding units and truncation points which correspond to the coding units. In response to determining that an examined collection of coefficients out of the plurality of collections of coefficients has a priority level equal to a global priority level, encoding a first un-encoded coding unit according to a local coding order of the collection of coefficients and reducing the priority level of the collection of coefficients; and after each of the collections of coefficients in the plurality are examined, decreasing the global priority level.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: June 28, 2011
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Yick Ming Yeung, Oscar Chi-Lim Au
  • Patent number: 7961694
    Abstract: Systems and methods for collaborative streaming among mobile terminals. Periodically, the mobile terminals may pull a portion of the data stream from a content provider coupled thereto over a primary channel and distribute the pulled data to neighboring mobile terminals, possibly including other mobile terminals pulling portions of the data stream from the content provider and passive mobile terminals that are only receiving pulled data. By transferring data over the secondary channel, the cost to any one terminal to receive the data stream is reduced.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: June 14, 2011
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Shueng Han Gary Chan, Man Fung Leung, Oscar Chi Lim Au
  • Publication number: 20110013803
    Abstract: We propose methods for generating a halftone image, in which each pixel takes one of two tone values. The generated image contains hidden data, which is present at data storage pixels chosen using a pseudo-random number generator. In a first case, the data is hidden within an existing halftone image by reversing the tone value at certain of the data storage pixels, and at pixels neighbouring the data storage pixels. In a second case, the halftone image is generated from a grey-scale image, and data is hidden during this conversion process.
    Type: Application
    Filed: September 23, 2010
    Publication date: January 20, 2011
    Inventors: Oscar Chi-Lim AU, Ming Sun Fu
  • Patent number: 7868788
    Abstract: Described herein is an efficient encryption method and system having improved security features based on randomness. The method and system utilize a random dictionary insertion and a random dictionary permutation, and a key stream generated by a stream cipher. Security analysis results show that the method and system provides a higher level of security without incurring any coding efficiency loss, compared with a existing encoding methods.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: January 11, 2011
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Jiantao Zhou
  • Publication number: 20100322306
    Abstract: Systems, methods, and apparatus for adaptively zeroing out transform coefficients utilizing a bit-stealing parameter are presented herein. A partitioning component can be configured to separate an image into blocks of video data. Further, a frequency transform component can be configured to transform pixels of a block of the blocks into transform coefficients. Furthermore, a bit-stealing quantization component configured to predefine quantization intervals. Moreover, the bit-stealing quantization component can modify a size of a quantization interval of the quantization intervals based on a variable bit-stealing parameter. Further, the bit-stealing component can quantize a transform coefficient of the transform coefficients, based on the quantization interval, to a quantized coefficient value of quantized coefficient values.
    Type: Application
    Filed: June 18, 2010
    Publication date: December 23, 2010
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Ngai Man Cheung, Xingyu Zhang
  • Publication number: 20100289816
    Abstract: Systems, methods, and apparatus for sampling images using edge detection are presented herein. A gradient component can calculate at least one gradient of a luminance of a block of pixels based on at least one direction; and select a minimum gradient of the at least one gradient of the luminance. Further, a direction component can determine a direction of the block based on a direction of the minimum gradient of the at least one gradient of the luminance. Moreover, a sampling component can alternately select subpixels of the block based on the direction of the block. In addition, a filter component can calculate at least one gradient of a color of a subpixel of the subpixels based on the at least one direction; determine a direction of the subpixel based on the at least one gradient of the color; and filter the subpixels based on the direction of the subpixel.
    Type: Application
    Filed: May 12, 2010
    Publication date: November 18, 2010
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Lu Fang
  • Patent number: 7804977
    Abstract: We propose methods for generating a halftone image, in which each pixel takes one of two tone values. The generated image contains hidden data, which is present at data storage pixels chosen using a pseudo-random number generator. In a first case, the data is hidden within an existing halftone image by reversing the tone value at certain of the data storage pixels, and at pixels neighboring the data storage pixels. In a second case, the halftone image is generated from a grey-scale image, and data is hidden during this conversion process.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: September 28, 2010
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi-Lim Au, Ming Sun Fu
  • Publication number: 20100215106
    Abstract: There is disclosed a method of digital signal compression, coding and representation, and more particularly a method of video compression, coding and representation system that uses multi-frame motion estimation and includes both device and method aspects. The invention also provides a computer program product, such as a recording medium, carrying program instructions readable by a computing device to cause the computing device to carry out a method according to the invention.
    Type: Application
    Filed: May 6, 2010
    Publication date: August 26, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi-Lim Au, Andy Chang
  • Publication number: 20100150463
    Abstract: There are disclosed three fast rate control methods that can efficiently reduce or remove the computation and memory usage redundancy over conventional PCRD methods. The first method, called successive bit-plane rate allocation (SBRA), assigns the maximum allowable bit-rate for each bit-plane of each code-block by using the currently available rate-distortion information only. The second method is called priority scanning rate allocation (PSRA). This first predicts the order of magnitude of each truncation point's rate-distortion slope and then encodes the truncation points based on the order (priority) information. The third method uses PSRA to obtain a significantly smaller amount of data than PCRD for optimal truncation and is called priority scanning with optimal truncation (PSOT). SBRA provides the highest computational complexity and memory usage reduction, and the lowest coding/transmission delay. The computational complexity reduction can be up to about 90% of the entropy coding process.
    Type: Application
    Filed: December 15, 2009
    Publication date: June 17, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Yick Ming Yeung, Oscar Chi-Lim Au
  • Publication number: 20100135588
    Abstract: This invention relates to method and apparatus for subpixel-based down-sampling. This invention implements an adaptive filter 140 based on edge detection, which removes visible color fringing artifacts while efficiently retaining sharpness.
    Type: Application
    Filed: December 2, 2008
    Publication date: June 3, 2010
    Applicant: Hong Kong Applied Science and Technology Research Institute Company Limited
    Inventors: Oscar Chi-Lim Au, Lu Fang, Hon Wah Wong, Yi Yang, Yan Huo
  • Patent number: 7720148
    Abstract: There is disclosed a method of digital signal compression, coding and representation, and more particularly a method of video compression, coding and representation system that uses multi-frame motion estimation and includes both device and method aspects. The invention also provides a computer program product, such as a recording medium, carrying program instructions readable by a computing device to cause the computing device to carry out a method according to the invention.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: May 18, 2010
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi-Lim Au, Andy Chang
  • Patent number: 7697715
    Abstract: We propose methods for generating a halftone image, in which each pixel takes one of two tone values. The generated image contains hidden data, which is present at data storage pixels chosen using a pseudo-random number generator. In a first case, the data is hidden within an existing halftone image by reversing the tone value at certain of the data storage pixels, and at pixels neighbouring the data storage pixels. In a second case, the halftone image is generated from a grey-scale image, and data is hidden during this conversion process.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: April 13, 2010
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi-Lim Au, Ming Sun Fu
  • Publication number: 20100074333
    Abstract: Described herein is a novel transcoding technique called lossless inter frame transcoding (LIFT) for improving the error resilience of video streaming. According to various embodiments, conventional coded blocks are selectively transcoded into new transcoded block. At the decoder, the transcoded block can be transcoded back to the conventional coded block when the prediction is available and can also be robustly decoded independently when the prediction is unavailable. According to another embodiment, an offline transcoding and online composing technique is provided for generating a composite frame using the transcoded and conventional coded blocks and adjusting the ratio of the transcoded blocks, thereby achieving error robustness scalability.
    Type: Application
    Filed: September 8, 2009
    Publication date: March 25, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Xiaopeng Fan
  • Publication number: 20100067688
    Abstract: Described herein are various embodiments of a coding technique that utilize a stream cipher for switching between first and second coding conventions for encoding a symbol sequence. The first coding convention specifies a first mapping between a symbol and a first codeword and the second coding convention specified a second mapping between the symbol and a second codeword. According to the invention, a key generated by the stream cipher is used to selected one of the first and second coding convention and the mapping of the selected coding convention is then utilized for encoding the symbol.
    Type: Application
    Filed: September 18, 2009
    Publication date: March 18, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Jiantao Zhou
  • Publication number: 20100039556
    Abstract: System and methodologies are provided herein for de-interlacing a video sequence. Various aspects described herein can utilize a motion adaptive video de-interlacing algorithm based on block-based texture classification and a multi-level decision hierarchy to interpolate missing fields of an interlaced video signal in the spatial and temporal domains. In accordance with various aspects described herein, respective blocks of an interlaced video sequence can be classified by a texture classifier as “textured” or “non-textured.” Based on this classification, one or more motion detection schemes can be utilized to determine whether the respective blocks are static or moving. Missing pixels from one or more blocks can then be estimated using the texture and motion classifications based on values of neighboring lines and/or pixels in the field from which the block was obtained as well as values of corresponding pixel locations in temporally adjacent fields.
    Type: Application
    Filed: August 12, 2008
    Publication date: February 18, 2010
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Tak Song Chong, Shing Fat Tu
  • Publication number: 20100027909
    Abstract: Images encoded at low-bit rate may suffer from blocking artifacts, which can dramatically degrade the visual quality of the images. In accordance with the claimed subject matter, a convex optimization approach is provided in order to mitigate such blocking artifacts. Based on the analysis of image coding process as well as natural image properties (e.g., image complexity), a set of constraint functions can be constructed. In addition, an objective function can be constructed based upon, e.g. analysis of a quantization noise model. All functions included in the set as well as the objective function can be convex function. Accordingly, image deblocking can be formulated as a convex optimization problem which can be easily solved using numerical methods. Moreover, the feasibility of the convex optimization problem can be utilized to detect the true object edges and avoid blurring.
    Type: Application
    Filed: August 4, 2008
    Publication date: February 4, 2010
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Liwei Guo