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: 20100020877
    Abstract: Multiple reference frame motion estimation for video frame blocks is provided. A plurality of copies of a block list of a reference frame can be loaded into texture memory. Encoding of video blocks of the video frame can be ordered to allow concurrent encoding of the video blocks. Furthermore, motion vector prediction can be performed concurrently for independent video blocks, the motion vectors can be related to each one of the plurality of copies of the block list of the reference frame and determined for the at least a portion of the plurality of blocks ordered for concurrent encoding. Additionally, a fast motion estimation algorithm can be concurrently performed on a number of video blocks to search surrounding blocks and compute motion vectors. Further, concurrent processing of multiple slices can be performed. Such concurrent processes can leverage the parallel architecture of at least one graphical processing unit.
    Type: Application
    Filed: July 23, 2008
    Publication date: January 28, 2010
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Man Cheung Kung
  • Publication number: 20090317017
    Abstract: A method and system map high dynamic range images to low dynamic range images. An input set of luminance values can be divided into separate regions corresponding to particular luminance value ranges. A region value can be determined for each region. Based at least in part on the region value, a quantity of range assigned to each region for tone mapping can be dynamically adjusted until each region meets a decision criterion or stopping condition, referred to herein as “concentration.” A region can be said to be concentrated if all luminance values therein are within a concentration interval or range. After a region is concentrated, it can be tone-mapped by quantization.
    Type: Application
    Filed: June 20, 2008
    Publication date: December 24, 2009
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Chun Hung Liu
  • Publication number: 20090316783
    Abstract: Systems and methodologies for employing bidirectionally decodable Wyner-Ziv video coding (BDWZVC) are described herein. BDWZVC can be used to generate M-frames, which have multiple reference frames at an encoder and can be forward and backward decodable. For example, optimal Lagrangian multipliers for forward and backward motion estimation can be derived and/or utilized. The optimal Lagrangian multiplier for backward motion estimation can be approximately twice as large as the optimal Lagrangian multiplier for forward motion estimation. Further, an optimal P-frame/M-frame selection scheme can be employed to enhance rate-distortion performance when video is transmitted over an error prone channel. Accordingly, a first frame in a group of pictures (GOP) can be encoded as an I-frame, a next m?1 frames can be encoded as P-frames, and a remaining n-m frames can be encoded as M-frames, where n can be a length of the GOP and m can be optimally identified.
    Type: Application
    Filed: June 18, 2008
    Publication date: December 24, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Xiaopeng Fan
  • Publication number: 20090309769
    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: Application
    Filed: June 17, 2009
    Publication date: December 17, 2009
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Jiantao Zhou
  • Publication number: 20090304264
    Abstract: The claimed subject matter relates to an architecture that can facilitate more efficient free view generation in Ray-Space by way of a Radon transform. The architecture can render virtual views based upon original image data by employing Ray-Space interpolation techniques. In particular, the architecture can apply the Radon transform to a feature epipolar plane image (FEPI) to extract more suitable slope or direction candidates. In addition, the architecture can facilitate improved block-based matching techniques in order to determine an optimal linear interpretation direction.
    Type: Application
    Filed: June 5, 2008
    Publication date: December 10, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Ling Hou
  • Publication number: 20090295607
    Abstract: Systems and methodologies for analyzing error recovery performance of variable length codes utilized for encoding and decoding data are provided herein. Synchronization recovery of a set of variable length codes can be evaluated assuming that an encoded bit stream is transmitted over a binary symmetric channel. Further, mean symbol error rates corresponding to each of the variable length codes in the set can be determined based upon the evaluation of the synchronization recovery. Moreover, a subset of the variable length codes with optimal error recovery can be selected as a function of the mean symbol error rates.
    Type: Application
    Filed: June 2, 2008
    Publication date: December 3, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Jiantao Zhou
  • Publication number: 20090295934
    Abstract: Demosaicking optimizations are provided for still and/or moving image (e.g., video) processes that efficiently generate viewable images. A demosaicking process selects a direction before performing interpolation in order to avoid interpolation across edges and also to minimize color artifacts. The direction to be selected is based on a direction similarity measurement. A digital capture device can includes a system that processes the image data by performing interpolation based on the direction similarity measurement(s) for color difference spaces. The images created based on the directional similarities demonstrate performance gains in peak signal to noise ratio (PSNR).
    Type: Application
    Filed: February 13, 2009
    Publication date: December 3, 2009
    Applicant: The Hong Kong University of Science and Technology
    Inventors: Oscar Chi Lim Au, Carman Ka Man Yuk
  • Publication number: 20090279600
    Abstract: Efficient encoding and/or decoding of digital video is provided using multiple candidate reference frames, making playback of the digital video optionally reversible. For example, a source can be encoded as duplex coded frames having multiple candidate reference frames. The reference frames can be previous or future frames, and the duplex coded frames can be encoded at a bit-rate that ensures lossless decoding using any of the candidate reference frames. Therefore, the duplex coded frames can encoded in normal and/or reverse temporal order. In this regard, the ability to decode digital video frames using either a single previous or future frame enables reversible digital video, bit-stream switching and video splicing arbitrary time points, and provides for increased error resilience.
    Type: Application
    Filed: May 6, 2008
    Publication date: November 12, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Xiaopeng Fan
  • Publication number: 20090279615
    Abstract: Systems and methodologies for concealing frame loss in a video transmission environment are provided herein. Multiple Description Coding (MDC) can be used as an Error Resilience technique for video coding. In case of transmission errors, Error Concealment can be combined with MDC to reconstruct a lost frame, such that the propagated error to following frames can be reduced. Further, multi-hypothesis decoding can be employed to enhance reconstructed video quality of MDC over packet loss networks. For instance, one or more frames after the lost frame in the same stream can be reconstructed using multi-hypothesis decoding, which combines directly decoding and temporally interpolating these frames. Moreover, output obtained from directly decoding and temporally interpolating each frame can be combined by generating a weighted sum of these hypotheses. Constant weights and/or adaptive weights (e.g., determined based on the minimum mean square error criterion) can be used for yielding the weighted sum.
    Type: Application
    Filed: May 7, 2008
    Publication date: November 12, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Mengyao Ma
  • Publication number: 20090268821
    Abstract: Block parallel fast motion estimation for blocks of a video frame is provided where encoding of video blocks can be ordered to allow concurrent encoding thereof. Furthermore, motion vector prediction can be performed concurrently for independent video blocks where requisite blocks for calculating the prediction of a given block can be previously encoded, but not all blocks depend from each other; thus, parallel motion vector estimation is possible. Additionally, a fast motion estimation algorithm can be concurrently performed on a number of video blocks to search surrounding blocks to compute motion vectors as well. The concurrent processes can leverage the parallel architecture of one or more graphical processing units (GPU).
    Type: Application
    Filed: April 29, 2008
    Publication date: October 29, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Man Cheung Kung
  • Publication number: 20090190845
    Abstract: Efficient temporal search range predication for motion estimation in video coding is provided where complexity of using multiple reference frames in multiple reference frame motion estimation (MRFME) can be evaluated over a desired performance level. In this regard, a gain can be determined for using regular motion estimation or MRFME, and a number of frames if the latter is chosen. Thus, the computational complexity of MRFME and/or a large temporal search range can be utilized where it provides at least a threshold gain in performance. Conversely, if the complex calculations of MRFME do not provide sufficient benefit to the video block prediction, a smaller temporal search range (a less number of reference frames) can be used, or regular motion editing can be chosen over MRFME.
    Type: Application
    Filed: January 24, 2008
    Publication date: July 30, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Liwei Guo
  • Publication number: 20090147849
    Abstract: GPU-based intra frame processing techniques are provided to selectively offload computation loading from a CPU to a GPU. By rearranging the 4×4 block encoding order, the process can benefit from a parallel processing mechanism available on the GPU. Block list size has an effect on speed and by using the optimal block list size for a selection, up to about two times speed improvement in intra frame processing can be achieved.
    Type: Application
    Filed: September 22, 2008
    Publication date: June 11, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Man Cheung Kung
  • Publication number: 20090135901
    Abstract: Encoding techniques are provided that consider decoder complexity when encoding video data. A complexity adaptive encoding algorithm encodes video data by encoding current frame data based on reference frame data taking into account an expected computational complexity cost of decoding the current frame data.
    Type: Application
    Filed: October 6, 2008
    Publication date: May 28, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Sui Yuk Lam
  • Publication number: 20090135911
    Abstract: Scalable Video Coding is recently attracting attentions due to its high flexibility. The current H.264/AVC scalable extension has adopted the Motion Compensated Temporal Filter (MCTF) framework to provide temporal scalability. In this paper, described is another fast motion estimation (ME) algorithm based on the MCTF framework. Simulation results show that the herein described algorithm can reduce the encoding complexity significantly while maintaining similar bit rate and PSNR, comparing with existing fast ME algorithms implemented in the reference software.
    Type: Application
    Filed: October 6, 2008
    Publication date: May 28, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Sui Yuk Lam
  • Publication number: 20090110062
    Abstract: Optimal Heegard-Berger coding methods, devices, and systems are provided based on the disclosed coding schemes. The disclosed schemes facilitate decoding even in the absence of side information, with lower coding complexity than conventional Wyner-Ziv based distributed coding techniques. The disclosed details enable various refinements and modifications according to system design considerations.
    Type: Application
    Filed: October 30, 2007
    Publication date: April 30, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim AU, Xiaopeng FAN
  • Publication number: 20090103617
    Abstract: Systems and methodologies for concealing errors related to INTRA-frame losses in a transmitted video signal are provided herein. Systems and methodologies provided herein can refine a lost INTRA-coded frame and its subsequent INTER-coded frames using INTRA-coded macroblocks that are provided in a video bitstream in accordance with a Random INTRA Refresh (RIR) scheme. When an INTRA-frame is lost, INTRA-coded macroblocks can be used to refine neighboring INTER-coded macroblocks based on region filling, spatial interpolation, or other algorithms that are based on the strong correlation between values of adjacent pixels in a video signal. Further, motion compensation can be used to refine an INTER-coded pixel having an INTRA-coded pixel in its motion trajectory.
    Type: Application
    Filed: October 22, 2007
    Publication date: April 23, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Mengyao Ma
  • Publication number: 20090080518
    Abstract: A method and a computer-readable medium containing computer program for simultaneously performing rate control and video denoising for video corrupted by noise are presented. Video data includes original video data and noise data. A variance of the noise data for each macroblock within a frame is estimated. Based on the estimated noise variance, a low bound quantization parameter is generated. The video data are reconstructed such that the distortion between the original video data and reconstructed video data is minimized over each macroblock within a frame. The minimization of the distortion between the original video and reconstructed video data is implemented using a quantization parameter that is equal to or larger than the low bound quantization parameter.
    Type: Application
    Filed: July 21, 2008
    Publication date: March 26, 2009
    Inventors: Oscar Chi Lim Au, Yan Chen
  • Publication number: 20090080688
    Abstract: Systems and methodologies for embedding a watermark in a few-color image are provided herein. A digital watermarking algorithm named Spatial Unified Key Insertion (SUKI) can be utilized, wherein adaptive threshold halftoning can be performed in combination with contour shaping and modification to embed a binary logo into a digital image. Watermarking can be performed for an image using SUKI without introducing “salt-and-pepper” artifacts into the image. Further, watermarking techniques described herein can embed data into an image with a considerably high payload while providing excellent resistance against JPEG compression and other attacks and introducing no additional colors into an image.
    Type: Application
    Filed: September 25, 2007
    Publication date: March 26, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Shu Kei Yip
  • Publication number: 20090074075
    Abstract: In advanced video coding standards such as H.264, macro-blocks belong to more advanced MB types, such as skipped and non-skipped macro-blocks. In non-skipped macro-blocks, the encoder determines whether each of 8×8 luminance sub-blocks and 4×4 chrominance sub-block of a macro-block is to be encoded, giving the different number of sub-blocks at each macro-block encoding times. It has been found that the correlation of bits between consecutive frames is high. This correlation is even higher after macro-block normalization by considering advanced macro-block types. Based on this bit characteristic, a fast real-time H.264 rate control scheme is herein described. The empirical example results suggest that this scheme can achieve PSNR gain over JM10.2.
    Type: Application
    Filed: September 14, 2007
    Publication date: March 19, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Dicky Chi Wah Wong
  • Publication number: 20090067495
    Abstract: Optimal selection of an inter mode is provided for video data being encoded to achieve enhanced error resilience when the video data is decoded. End to end distortion cost from encoder to decoder for inter mode selection is determined based on residue energy and quantization error. Using the distortion cost function based on residue energy and quantization error, and an optimal Lagrangian parameter, the optimal inter mode is selected for use during encoding for maximum error resilience. The optimal Lagrangian parameter can be set to be proportional to an error-free Lagrangian parameter with a scale factor determined by packet loss rate.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 12, 2009
    Applicant: THE HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
    Inventors: Oscar Chi Lim Au, Yan Chen