Patents by Inventor Philip A. Chou

Philip A. Chou 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: 6532562
    Abstract: “Correction of errors and losses occurring during a receiver-driven layered multicast (RLM) of real-time media over a heterogeneous packet network such as the Internet is accomplished by augmenting RLM with one or more layers of error correction information. Each receiver separately optimizes the quality of received audio and video information by subscribing to at least one error correction layer. Ideally, each source layer in a RLM would have one or more associated multicasted error correction data streams (i.e., layers). Each error correction layer contains information that can be used to replace lost packets from the associated source layer. More than one error correction layer is proposed as some of the error correction packets contained in the data stream needed to replace the packets lost in the associated source stream may themselves be lost in transmission.
    Type: Grant
    Filed: May 21, 1999
    Date of Patent: March 11, 2003
    Inventors: Philip A. Chou, Albert S. Wang, Sanjeev Mehrotra
  • Patent number: 6470469
    Abstract: A projection onto convex sets (POCS)-based method for consistent reconstruction of a signal from a subset of quantized coefficients received from an N×K overcomplete transform. By choosing a frame operator F to be the concatenization of two or more K×K invertible transforms, the POCS projections are calculated in RK space using only the K×K transforms and their inverses, rather than the larger RN space using pseudo inverse transforms. Practical reconstructions are enabled based on, for example, wavelet, subband, or lapped transforms of an entire image. In one embodiment, unequal error protection for multiple description source coding is provided. In particular, given a bit-plane representation of the coefficients in an overcomplete representation of the source, one embodiment of the present invention provides coding the most significant bits with the highest redundancy and the least significant bits with the lowest redundancy.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: October 22, 2002
    Assignee: Microsoft Corp.
    Inventors: Philip A. Chou, Sanjeev Mehrotra, Albert S. Wang
  • Patent number: 6460153
    Abstract: A projection onto convex sets (POCS)-based method for consistent reconstruction of a signal from a subset of quantized coefficients received from an N×K overcomplete transform. By choosing a frame operator F to be the concatenization of two or more K×K invertible transforms, the POCS projections are calculated in RK space using only the K×K transforms and their inverses, rather than the larger RN space using pseudo inverse transforms. Practical reconstructions are enabled based on, for example, wavelet, subband, or lapped transforms of an entire image. In one embodiment, unequal error protection for multiple description source coding is provided. In particular, given a bit-plane representation of the coefficients in an overcomplete representation of the source, one embodiment of the present invention provides coding the most significant bits with the highest redundancy and the least significant bits with the lowest redundancy.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: October 1, 2002
    Assignee: Microsoft Corp.
    Inventors: Philip A. Chou, Sanjeev Mehrotra, Albert S. Wang
  • Patent number: 6449653
    Abstract: The production of an interleaved multimedia stream for servers and client computers coupled to each other by a diverse computer network which includes local area networks (LANs) and/or wide area networks (WANs) such as the internet. Interleaved multimedia streams can include compressed video frames for display in a video window, accompanying compressed audio frames and annotation frames. In one embodiment, a producer captures separate video/audio frames and generates an interleaved multimedia file. In another embodiment, the interleaved file include annotation frames which provide either pointer(s) to the event(s) of interest or include displayable data embedded within the annotation stream. The interleaved file is then stored in the web server for subsequent retrieval by client computer(s) in a coordinated manner, so that the client computer(s) is able to synchronously display the video frames and displayable event(s) in a video window and event window(s), respectively.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: September 10, 2002
    Assignee: Microsoft Corporation
    Inventors: Anders Edgar Klemets, Philip A. Chou
  • Publication number: 20020034333
    Abstract: A transmission method for video image data using an embedded bit stream in a hierarchical table-lookup vector quantizer comprises the steps encoding an image using hierarchical vector quantization and an embedding process to obtain an embedded bit stream for lossless transmission. The bit stream is selectively truncated and decoded to obtain a reconstructed image.
    Type: Application
    Filed: July 30, 2001
    Publication date: March 21, 2002
    Applicant: Xerox Corporation.
    Inventors: Mohan Vishwanath, Philip A. Chou, Navin Chaddha
  • Patent number: 6345126
    Abstract: A transmission method for video image data using an embedded bit stream in a hierarchical table-lookup vector quantizer comprises the steps encoding an image using hierarchical vector quantization and an embedding process to obtain an embedded bit stream for lossless transmission. The bit stream is selectively truncated and decoded to obtain a reconstructed image.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: February 5, 2002
    Assignee: Xerox Corporation
    Inventors: Mohan Vishwanath, Philip A. Chou, Navin Chaddha
  • Publication number: 20010013068
    Abstract: The production of an interleaved multimedia stream for servers and client computers coupled to each other by a diverse computer network which includes local area networks (LANs) and/or wide area networks (WANs) such as the internet. Interleaved multimedia streams can include compressed video frames for display in a video window, accompanying compressed audio frames and annotation frames. In one embodiment, a producer captures separate video/audio frames and generates an interleaved multimedia file. In another embodiment, the interleaved file include annotation frames which provide either pointer(s) to the event(s) of interest or include displayable data embedded within the annotation stream. The interleaved file is then stored in the web server for subsequent retrieval by client computer(s) in a coordinated manner, so that the client computer(s) is able to synchronously display the video frames and displayable event(s) in a video window and event window(s), respectively.
    Type: Application
    Filed: March 25, 1997
    Publication date: August 9, 2001
    Inventors: ANDERS EDGAR KLEMETS, PHILIP A. CHOU
  • Patent number: 5883986
    Abstract: A method and system for automatically modifying an original transcription produced as the output of a recognition operation produces a second, modified transcription, such as, for example, automatically correcting an errorful transcription produced by an OCR operation. The invention uses information in an input text image of character images and in an original transcription associated with the input text image to modify aspects of a formal image source model that models as a grammar the spatial image structure of a set of text images. A recognition operation is then performed on the input text image using the modified formal image source model to produce a second, modified transcription. When the original transcription is errorful, the second transcription is a corrected transcription. Several aspects of the formal image source model may be modified; in particular, character templates to be used in the recognition operation are trained in the font of the glyphs occurring in the input text image.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: March 16, 1999
    Assignee: Xerox Corporation
    Inventors: Gary E. Kopec, Philip A. Chou, Leslie T. Niles
  • Patent number: 5655058
    Abstract: A method for segmenting audio data, comprising speech from a plurality of individual speakers, according to speaker is provided. The method comprises providing individual HMMs for each individual speaker, each individual HMM including at least one state, and constructing a speaker network HMM by connecting the individual HMMs in parallel. The audio data is then divided into segments by determining a most likely sequence of states through the speaker network HMM, each of the segments being associated with one of the individual HMMs. Afterward, the speaker of each of the segments is identified. The segmented data may be used to form an index into the audio data according to speaker.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: August 5, 1997
    Assignee: Xerox Corporation
    Inventors: Vijay Balasubramanian, Francine R. Chen, Philip A. Chou, Donald G. Kimber, Alex D. Poon, Karon A. Weber, Lynn D. Wilcox
  • Patent number: 5606643
    Abstract: A processor controlled system for correlating an electronic index according to speaker for audio data being recorded in real time. The system includes a source of training data for each of the plurality of individual speakers and audio input system for providing real time audio data including speech for the individual speakers. The audio data is converted into spectral feature data by an audio processor, and is simultaneously recorded on a storage medium by a recording device. A system processor accepts the training data to create individual speaker models, which are combined in parallel to form a speaker network. The system processor then accepts the spectral feature data of the audio data and, using the speaker network, determines segments in the audio data corresponding to each speaker.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: February 25, 1997
    Assignee: Xerox Corporation
    Inventors: Vijay Balasubramanian, Francine R. Chen, Philip A. Chou, Donald G. Kimber, Alex D. Poon, Karon A. Weber, Lynn D. Wilcox
  • Patent number: 5594809
    Abstract: A technique for automatically producing, or training, a set of bitmapped character templates defined according to the sidebearing model of character image positioning uses as input a text line image of unsegmented characters, called glyphs, as the source of training samples. The training process also uses a transcription associated with the text line image, and an explicit, grammar-based text line image source model that describes the structural and functional features of a set of possible text line images that may be used as the source of training samples. The transcription may be a literal transcription of the line image, or it may be nonliteral, for example containing logical structure tags for document formatting and layout, such as found in markup languages.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: January 14, 1997
    Assignee: Xerox Corporation
    Inventors: Gary E. Kopec, Philip A. Chou, Leslie T. Niles
  • Patent number: 5526444
    Abstract: An image decoding and recognition system and method comprising a fast heuristic algorithm using hidden Markov models (HMM). The new search algorithm, called an "iterative complete path" (ICP) algorithm, patterned after well-known branch-and-bound (B&B) methods, significantly reduces the complexity and improves the speed of HMM image decoding without sacrificing the optimality of the straightforward procedure. An advantageous form of the heuristic functions which is useful in applying the ICP algorithm to text-like images is described. The ICP algorithm is directly applicable to the separable type of finite-state source models. Also disclosed is a technique for transforming more general source models into such a separable form.
    Type: Grant
    Filed: May 7, 1993
    Date of Patent: June 11, 1996
    Assignee: Xerox Corporation
    Inventors: Gary E. Kopec, Anthony C. Kam, Philip A. Chou
  • Patent number: 5321773
    Abstract: An image recognition system, in particular for document image recognition, using an imaging model employing a 2-dimensional finite state automaton corresponding to a regular string grammar. This approach is not only less computationally intensive than previous grammar-based approaches to document image recognition, but also can handle a wider variety of image types. Features of the imaging model include a sidebearing model of glyph positioning, an image decoder based on linear scheduling theory for regular interative algorithms, the combining of overlapping image sub-regions, and a least-squares estimation procedure for measuring character parameters from character samples in the image.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: June 14, 1994
    Assignee: Xerox Corporation
    Inventors: Gary E. Kopec, Philip A. Chou
  • Patent number: 5020112
    Abstract: A method of automatically identifying bitmapped image objects. Each of a set of templates in an object template library is compared with all areas of like size of a bitmapped image. A set of signals is generated for each such comparison that satisfies a defined matching criteria between the template and the image area being compared. The set of signals identifies the object based on the matching template, the location of the object in the image and an indication of the goodness of the match between the object and the template. A series of possible parse trees are formed that describe the image with a probability of occurrence for each tree. Each parent node and its child nodes of each parse tree satisfies a grammatical production rule in which some of the production rules define spatial relationships between objects in the image. The one of the possible parse trees which has the largest probability of occurence is selected for further utilization.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: May 28, 1991
    Assignee: At&T Bell Laboratories
    Inventor: Philip A. Chou