Patents by Inventor Wen-Hsiung Chen

Wen-Hsiung Chen 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: 7486212
    Abstract: Coding quantized transform coefficients as occur in image compression includes, for a subset of coefficient amplitude values coding by a first method corresponding to each amplitude of the subset, events of a run of zero or more zero-valued coefficients ending in the single non-zero amplitude, coding by a second method events of a run of zero or more zero-valued coefficients ending in any single non-zero amplitude not in the subset, and coding by a third method the amplitude values of the concatenation of the non-zero amplitude not in the subset. The coding methods produce variable length codewords. The method is suitable for series that have scattered non-zero-valued coefficients.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: February 3, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Wen-hsiung Chen, John A. Toebes
  • Patent number: 7483584
    Abstract: A method and an apparatus of image compression, and a memory to store a data structure for compression. The method includes, for an ordered series of quantized coefficients of a transform of an image block, forming from the series events that are a run of non-zero-valued coefficients in a first contiguous region defined by a breakpoint, a run of zero-valued coefficients in the first region, or a run of zero-valued coefficients that ends in a non-zero-amplitude coefficient in a second region defined by the breakpoint. A codeword is formed for each runlength of non-zero-valued and zero-valued coefficients in the first region using a first and a second coding method, respectively, and, and encoding the runs of zero-valued coefficient that end in a non-zero value in the second region according to a third coding method, including providing an exception codeword when the ending amplitude is not 1.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: January 27, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Wen-hsiung Chen, Fang Wu, Gregory D. Pelton, John A. Toebes
  • Publication number: 20090016440
    Abstract: Particular embodiments include a method, an apparatus, and logic embodied in tangible computer-readable medium that when executed carries out a method of encoding an ordered sequence of quantized transform coefficients of a block of image data. One embodiment is a context adaptive variable length coding method that includes position coding the positions of zero-valued and non-zero valued coefficients by either a mixed method that encodes either the run length of zeroes preceding a non-zero coefficient or the run length of nonzero-valued coefficients preceding a zero-valued coefficients. Another includes position coding that uses a variable length code for two parameters respectively indicating the number of zero-valued coefficient positions and nonzero-valued coefficient positions still to be coded.
    Type: Application
    Filed: July 9, 2007
    Publication date: January 15, 2009
    Inventors: Dihong Tian, Wen-hsiung Chen, Pi Sheng Chang
  • Patent number: 7471840
    Abstract: A method, apparatus, and carrier medium to encode a series of quantized transform coefficients. The method includes identifying events that each includes a run of zero-valued coefficients preceding a run of one or more non-zero-valued coefficients, and for each such event, jointly encoding the run lengths of the preceding run of zero-valued coefficients and the following run of non-zero-valued coefficients with a codeword, such that for at least some events, relatively more likely-to-occur pairs of runlengths are encoded by a shorter codeword than relatively less likely-to-occur runlengths. The method further includes encoding each amplitude in the run of consecutive non-zero-valued coefficients, and encoding the signs of such coefficients. The method is applicable to encoding a region in the series where there is likely to be a cluster of non-zero-valued coefficients.
    Type: Grant
    Filed: August 18, 2004
    Date of Patent: December 30, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: John A. Toebes, Wen-hsiung Chen, Fang Wu, Dov Rosenfeld
  • Patent number: 7471841
    Abstract: A method, a carrier medium, and an apparatus to process a plurality of ordered series of quantized coefficients of a block of an image to reduce the amount of data used to represent the image. The method includes establishing a breakpoint along the ordering of the series to define a first contiguous region and a second contiguous region, such that clusters of consecutive signals of non-zero values occur mostly in the first contiguous region. Establishing the breakpoint uses statistics calculated from at least a subset of the plurality, the statistics being of where, along the ordering of the plurality of the series, coefficients of any non-zero value occur in clusters of consecutive non-zero coefficients. For each series in the plurality, the signals in the first region are encoded using a first region encoding method, and the signals in the second region are encoded using a second region encoding method.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: December 30, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Fang Wu, Wen-hsiung Chen
  • Patent number: 7454076
    Abstract: A method and an apparatus of image compression, and a memory to store a data structure for compression. The method includes, for an ordered series of quantized coefficients of a transform of an image block, forming from the series events each with a run of non-zero-valued coefficients in a first contiguous region defined by a breakpoint, a run of zero-valued coefficients in the first region, or a run of zero-valued coefficients in a second region defined by the breakpoint. The breakpoint defines the first region and a second continuous region in the series. Codewords are formed for each runlength of non-zero-valued and zero-valued coefficients in the first region according to a first and a second coding method, respectively, and a codeword is formed for the non-zero amplitudes according to a first amplitude coding method. The runlengths of zero-valued coefficients in the second region are encoding using a third coding method.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: November 18, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Wen-hsiung Chen, Fang Wu, Gregory D. Pelton, John A. Toebes
  • Patent number: 7454073
    Abstract: A method and apparatus to variable length code an ordered series of quantized transform coefficients of an image block. The method classifies the series into one of a plurality of classes. Each class has a corresponding coding process that is applicable to the statistical distribution of the coefficients in the series. The series is coded according to the particular corresponding coding process of the class of the classifying.
    Type: Grant
    Filed: August 3, 2004
    Date of Patent: November 18, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Wen-hsiung Chen, Fang Wu, Gregory D. Pelton, John A. Toebes
  • Publication number: 20080240571
    Abstract: An apparatus, a method, and a computer-readable medium having instructions encoded thereon that when executed cause a method to be carried out. The method includes dividing at least a portion of a picture of a video stream into parts of blocks, and processing the parts in parallel by a plurality of interconnected processors. The processing of a respective part by its respective processor includes determining block-level temporal difference features. Each processor also performs coding functions on its respective part of the picture. The method also includes block-level processing using the block-level temporal difference features to determine which blocks in the picture are likely to be that of a face, the block-level processing being at the granularity of at least a block. In one version, the processing in each processor includes edge detection and color segmentation to determine block-level edge features including block-level color-segmented edge features that are then used in the block level processing.
    Type: Application
    Filed: February 14, 2008
    Publication date: October 2, 2008
    Inventors: Dihong Tian, Joseph T. Friel, J. William Mauchly, Wen-hsiung Chen
  • Publication number: 20080240237
    Abstract: An apparatus, a method, and a computer-readable medium having instructions encoded thereon that when executed cause a method to be carried out. The method includes dividing at least a portion of a picture of a video stream into parts of blocks, and processing the parts in parallel by a plurality of interconnected processors. The processing of a respective part by its respective processor includes edge detection and color segmentation to determine block-level edge features including block-level color-segmented edge features. Each processor also performs coding functions on its respective part of the picture. The method also includes block-level processing using the block-level edge features to determine which blocks in the picture are likely to be that of a face, the block-level processing being at the granularity of at least a block.
    Type: Application
    Filed: January 28, 2008
    Publication date: October 2, 2008
    Inventors: Dihong Tian, Joseph T. Friel, J. William Mauchly, Wen-hsiung Chen
  • Publication number: 20080199088
    Abstract: For data compressed using the first compression method that includes codewords generated by variable length coding sets of quantized transform coefficients using a first variable length coding method, decoding the codewords to create ordered sets of quantized transform coefficients, each created set forming an ordered series of quantized transform coefficients, and re-encoding the created ordered sets of quantized transform coefficients using a second variable length coding method to produce a re-coded set of codewords. The second variable length coding method produces shorter codewords, on average, than the first variable length coding method. The decoding and re-encoding is a lossless process such that no additional quantization or other errors are introduced to the received data by the method.
    Type: Application
    Filed: February 16, 2007
    Publication date: August 21, 2008
    Inventors: Wen-hsiung Chen, Dov Rosenfeld
  • Publication number: 20080181299
    Abstract: A method, and apparatus, and logic encoded in one or more computer-readable tangible medium to carry out a method. The method is to code an ordered sequence of quantized transform coefficients of a block of image data using a hybrid coding method that includes determining a breakpoint location in the sequence between a low-frequency region and a high-frequency region; coding the low-frequency region using a selected low-frequency variable length coding method; coding the high-frequency region using a selected high-frequency variable length coding method; and coding the location of the breakpoint. The breakpoint location is determined as a function of properties of neighboring blocks such that little if any information needs to be sent to a decoder about the breakpoint of a block or multi-block partition, and the decoder can use the properties of neighboring blocks to determine the breakpoint used to code a to-be-decoded sequence or sequences of a block or a multi-block partition.
    Type: Application
    Filed: March 15, 2007
    Publication date: July 31, 2008
    Inventors: Dihong Tian, Wen-hsiung Chen, Pi Sheng Chang, John A. Toebes
  • Publication number: 20080181296
    Abstract: A method, and apparatus, and logic encoded in one or more computer-readable tangible medium to carry out a method. The method is to code a plurality of ordered sequences of quantized transform coefficients of a corresponding plurality of blocks of image data using a hybrid coding method that includes determining a breakpoint location in the sequence between a low frequency region and a high frequency region; coding the low-frequency region using a selected low-frequency variable length coding method; coding the high-frequency region using a selected high-frequency variable length coding method; and coding the location of the breakpoint. The plurality of blocks include adjacent blocks and form a multi-block partition. The breakpoint location is determined as a function of the sequences of the multi-block partition such that different multi-block partitions can have different breakpoints.
    Type: Application
    Filed: March 15, 2007
    Publication date: July 31, 2008
    Inventors: Dihong Tian, Wen-hsiung Chen, Pi Sheng Chang, John A. Toebes
  • Publication number: 20080170613
    Abstract: A method, and apparatus, and logic encoded in one or more computer-readable tangible medium to carry out a method of determining a breakpoint position in an ordered sequence of quantized transform coefficients of a block of image data for a hybrid variable length coding the ordered sequence. The breakpoint location in the sequence is between a low-frequency region and a high-frequency region. The hybrid variable length coding method includes coding the low-frequency region using a selected low-frequency variable length coding method; coding the high-frequency region using a selected high-frequency variable length coding method; and coding the position in the sequence of the breakpoint. The breakpoint location is determining uses a relatively simple and fast method based on pre-defined cost criteria. A method is included that instead of coding the breakpoint separately, codes the breakpoint jointly with coefficient events.
    Type: Application
    Filed: December 20, 2007
    Publication date: July 17, 2008
    Inventors: Dihong Tian, Pi Sheng Chang, Wen-hsiung Chen
  • Publication number: 20080170625
    Abstract: A method, and apparatus, and logic encoded in one or more computer-readable tangible medium to carry out a method. The method is to code an ordered sequence of quantized transform coefficients of a block of image data using a hybrid coding method that includes determining a breakpoint location in the sequence between a low frequency region and a high frequency region; coding the low-frequency region using a selected low-frequency variable length coding method; coding the high-frequency region using a selected high-frequency variable length coding method; and coding the location of the breakpoint. The breakpoint location is determined as a function of the sequence such that different sequences can have different breakpoints.
    Type: Application
    Filed: March 15, 2007
    Publication date: July 17, 2008
    Inventors: Dihong Tian, Pi Sheng Chang, Wen-hsiung Chen
  • Patent number: 7394942
    Abstract: A method and an apparatus to encode a series of quantized coefficients of a transform of a block of image data. The method includes forming modes for each encountered non-zero amplitude and forming events for the modes in the mode-modified series formed by setting to zero all non-zero amplitudes other than the amplitude defining the mode. An event for modes for amplitudes greater than 1 is a run of none or more zero-valued coefficients followed a non-zero amplitude in the mode-modified series. A first mode is defined for amplitude 1 wherein an event is a run of none or more zero-valued coefficients followed the amplitude 1 coefficient in the mode-modified series. In another embodiment, a first mode is defined for amplitude 1 wherein an event is a run in the mode-modified series of none or more zero-valued coefficients followed by a run of one of a predefined set of sequences, each sequence in the set being a sequence of l's and 0's starting with a coefficient of amplitude 1.
    Type: Grant
    Filed: January 5, 2007
    Date of Patent: July 1, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Wen-hsiung Chen, Fang Wu, Gregory D. Pelton
  • Patent number: 7324699
    Abstract: A method and an apparatus to decode a bitstream that includes codewords formed by a method of encoding series of quantized coefficients of a transform of a block of image data. The encoding method includes forming events from the series of quantized transform coefficients, each event being a run of none or more zero-valued coefficients followed by a run of one of a predefined set of sequences, each sequence in the set being either a single coefficient of amplitude greater than one, or a sequence of 1's and 0's starting with a coefficient of amplitude 1. The encoding method includes forming a codeword for each formed event. The decoding includes decoding recognized events until all the coefficients in a series of quantized transform coefficients is formed.
    Type: Grant
    Filed: February 15, 2007
    Date of Patent: January 29, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Wen-hsiung Chen, Fang Wu, Gregory D. Pelton
  • Publication number: 20070279266
    Abstract: Coding quantized transform coefficients as occur in image compression includes, for a subset of coefficient amplitude values coding by a first method corresponding to each amplitude of the subset, events of a run of zero or more zero-valued coefficients ending in the single non-zero amplitude, coding by a second method events of a run of zero or more zero-valued coefficients ending in any single non-zero amplitude not in the subset, and coding by a third method the amplitude values of the concatenation of the non-zero amplitude not in the subset. The coding methods produce variable length codewords. The method is suitable for series that have scattered non-zero-valued coefficients.
    Type: Application
    Filed: June 11, 2007
    Publication date: December 6, 2007
    Inventors: Wen-hsiung Chen, John Toebes
  • Publication number: 20070277219
    Abstract: A method of reducing the channel selection transition delay from a first media data channel to a second media data channel includes the operations of accumulating an independent media data frame and any related dependent media data frames based on a first decoder decoding at least a first portion of a second channel to form a second channel current media state, receiving a channel change request from a second decoder to change decoding to the second media channel, identifying an insertion position for a current independent frame relative to a current second channel frame set, and generating the current independent frame based on the second channel current media state corresponding to the insertion position. The dependent media data frames are used to modify the second channel current media state based on the independent media data frame.
    Type: Application
    Filed: May 26, 2006
    Publication date: November 29, 2007
    Inventors: John Toebes, Wen-Hsiung Chen, Jack Cham, Ping Li
  • Patent number: 7294202
    Abstract: Process for fabricating self-assembled nanoparticles on buffer layers without mask making and allowing for any degree of lattice mismatch; that is, binary, ternary or quaternary nanoparticles comprising Groups III-V, II-VI or IV-VI. The process includes a first step of applying a buffer layer, a second step of turning on the purge gas to modulate the first reactant to the lower first flow rate, then the second reactant is supplied to the buffer layer to form a metal-rich island on the buffer layer, and a third step of turning on purge gas again to modulate the first reactant to the higher second flow rate onto the buffer layer. On the metal-rich island is formed the nanoparticles of the binary, ternary or quaternary III-V, II-VI and IV-IV semiconductor material. This is then recrystallized under the first reactant flow at high temperature forming high quality nanoparticles.
    Type: Grant
    Filed: December 6, 2004
    Date of Patent: November 13, 2007
    Assignee: National Chiao Tung University
    Inventors: Wei-Kuo Chen, Ming-Chih Lee, Wu-Ching Chou, Wen-Hsiung Chen, Wen-Cheng Ke
  • Publication number: 20070200956
    Abstract: An apparatus, a method and a computer program product for correcting image data for the presence of a ghost image. The image data is for acceptance by a device that includes a partially-silvered finite-thickness reflector or similar element to provide a reflection of an image for display. The ghost image is a shifted, attenuated version of the image data. The method includes subtracting a first correction term from the image data, the first correction term being a shifted and attenuated version of the image data, the shift being the same as that between the image data and the ghost image, and the attenuation matching the attenuation of the ghost image caused by the device. The processed image data is input to the device. For a small enough attenuation of the ghost image, substantially no ghost image of the image data is displayed by the device.
    Type: Application
    Filed: February 28, 2006
    Publication date: August 30, 2007
    Inventors: Richard Wales, Philip Graham, Wen-hsiung Chen, William May