Patents by Inventor Chai Wah Wu

Chai Wah Wu 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: 6954290
    Abstract: Pages of books are copied without distortion due to curvature of the page near the book binding or the distortion in a copied page is corrected using the spacing of equidistant bars on tape strips applied to the top and bottom edges of a page before copying. The tape is preferably transparent and rather narrow and easily attached to a page to be copied. The first step in the distortion correction procedure is to locate the bars at the top and bottom of the page. The distortion of the spacing between the imaged bars is computed based on the known distance between the equidistant bars. The computed distortion of the spacing is then input to a distortion correction algorithm. The output of the distortion correction algorithm generates a corrected image. This image may also optionally delete the bars so that they are not printed in the copy. The corrected image is then copied.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: October 11, 2005
    Assignee: International Business Machines Corporation
    Inventors: Gordon W. Braudaway, Frank P. Giordano, Marco Martens, Charles P. Tresser, Chai Wah Wu, Charles A. Micchelli
  • Patent number: 6907527
    Abstract: A method (and system) for generating an output file from a source file where benign modifications to a content of the output file still render the output file authentic, includes constructing an index vector from the source file, quantizing the source file, generating an authentication mark from the quantized source file and the index vector, generating an authentication tag by appending the index vector to the authentication mark, and generating the output file by appending the authentication tag to the source file.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: June 14, 2005
    Assignee: International Business Machines Corporation
    Inventor: Chai Wah Wu
  • Patent number: 6873977
    Abstract: A method and system offer confidential purchase of electronic data which can be used without any need of knowledge in cryptography nor mastery of computer use beyond usual usage of the World Wide Web (WWW). The method and system which guarantee confidentiality as long as there is no collusion between agents working for a large number of reputable companies whose references can be easily checked on the Internet before proceeding to the order. In addition, the method and system allow for guaranteed payment and offer recourse in case of improper delivery.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: March 29, 2005
    Assignee: International Business Machines Corporation
    Inventors: Alok Aggarwal, Pradeep K. Dubey, Charanjit Singh Jutla, Vijay Kumar, Marco Martens, Michael Ira Shub, Charles P. Tresser, Chai Wah Wu
  • Patent number: 6870643
    Abstract: A method (and system) for producing a halftoned image, includes calculating errors corresponding to a plurality of different viewing conditions of a halftone image, and minimizing a function of the errors, such that the halftoned image appears as a different image under different viewing conditions. Alternatively, in another embodiment, the halftoned image appears as the same image under different viewing conditions.
    Type: Grant
    Filed: January 31, 2001
    Date of Patent: March 22, 2005
    Assignee: International Business Machines Corporation
    Inventors: Gerhard Robert Thompson, Steven Lorenz Wright, Chai Wah Wu
  • Publication number: 20040233477
    Abstract: A method is disclosed for halftoning images either via a direct method or a threshold array construction. The method includes comparing a pattern to an image and calculating a first potential in order to determine a first set of pixels to move; calculating a second potential in order to determine a second set of pixels in which to move the first set of pixels; and then moving pixels in the first set of pixels having high first potentials to pixel locations in the second set of pixels having low second potentials. The method may further include an inner program loop that decreases the number of pixels to move in the first and second sets and iteratively repeats the above steps; and an outer program loop that resets the number of pixels moved in the first and second sets and iteratively repeating the process to further optimize the pattern.
    Type: Application
    Filed: May 21, 2003
    Publication date: November 25, 2004
    Applicant: International Business Machines Corporation
    Inventors: Mikel J. Stanich, Gerhard R. Thompson, Chai Wah Wu
  • Patent number: 6807530
    Abstract: A method and apparatus which enables customers to remotely order goods from a merchant and receive the goods without revealing customer identity or address to the merchant, nor revealing what is bought to the bank or payment agency, and more generally to preserve as much anonymity as required such that no party except the customer has complete information about a transaction. The method uses clearing houses or encryption to break links between customer information and the merchant.
    Type: Grant
    Filed: August 5, 1998
    Date of Patent: October 19, 2004
    Assignee: International Business Machines Corporation
    Inventors: Michael Shub, Charles Philippe Tresser, Chai Wah Wu
  • Patent number: 6801220
    Abstract: Viewing angle characteristics of a liquid crystal display (LCD) are improved by reducing the number of subpixels in an image with mid-tone luminance values. In a preferred embodiment, a first table of entries associating subpixel intensity values and subpixel luminance values for a LCD in at least one viewing angle direction is provided. A target intensity value is determined from the first table, corresponding to the average subpixel luminance over a small number of adjacent subpixels. A second table of entries associates the target intensity values with intensity values above and below the target. The adjacent subpixel intensity values are modified according to the second table, thereby reducing the number of subpixels with mid-tone luminance values. The subpixel data is preferably processed within a portion of an application-specific integrated circuit (ASIC), contained within the display module.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: October 5, 2004
    Assignee: International Business Machines Corporation
    Inventors: Paul F. Greier, Kenneth C. Ho, Richard Ian Kaufman, Steven Edward Millman, Gerhard R. Thompson, Steven L. Wright, Chai Wah Wu
  • Patent number: 6687023
    Abstract: A data processing system and method are described for generating a halftone screened image from an input image. A first threshold matrix is generated which, when utilized to halftone a solid gray input image, generates a first halftoned output image which is a plurality of generally solid vertical lines. The first threshold matrix includes a plurality of matrix elements arranged in a plurality of rows and a plurality of columns. A plurality of groups of the matrix elements are shifted within the first threshold matrix to create a second threshold matrix which, when utilized to halftone the solid gray input image, generates a second halftoned output image which is a checkerboard type pattern of alternating black or white blocks. In one embodiment, groups of the plurality of the rows are shifted horizontally over by at least one adjacent column to generate the second matrix.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: February 3, 2004
    Assignee: International Business Machines Corporation
    Inventors: Danielle Dittrich, Larry Ernst, Gerhard Robert Thompson, Chai Wah Wu
  • Publication number: 20030063318
    Abstract: A digital halftoning technique for controlling a spot function to address gear noise, printer stress, and general print quality is disclosed. A method for generating a spot for use in halftoning according to the present invention includes defining a spot function that combines two functions selected to provide a predetermined spot shape for use in a halftone cell and scaling the spot function using a scaling function that varies according to a value of a first and second spot function ordinate. Asymmetric modulation of spot functions is used to control the touching of adjacent spots, and to change the shape of the spots with the gray region. The resulting non-separable shape-changing spot function can reduce printer stress and improve print quality.
    Type: Application
    Filed: July 3, 2001
    Publication date: April 3, 2003
    Applicant: International Business Machines Corporation
    Inventors: Jennifer Quirin Trelewicz, Danielle K. Dittrich, Yue Qiao, Gerhard Robert Thompson, Chai Wah Wu
  • Publication number: 20020171853
    Abstract: A method (and system) of embedding data into an image, includes producing an extended image using a halftoning algorithm on a collection of images, and projecting the extended image onto its first coordinates.
    Type: Application
    Filed: May 3, 2001
    Publication date: November 21, 2002
    Applicant: International Business Machines Corporation
    Inventor: Chai Wah Wu
  • Publication number: 20020149598
    Abstract: Viewing angle characteristics of a liquid crystal display (LCD) are improved by reducing the number of subpixels in an image with mid-tone luminance values. In a preferred embodiment, a first table of entries associating subpixel intensity values and subpixel luminance values for a LCD in at least one viewing angle direction is provided. A target intensity value is determined from the first table, corresponding to the average subpixel luminance over a small number of adjacent subpixels. A second table of entries associates the target intensity values with intensity values above and below the target. The adjacent subpixel intensity values are modified according to the second table, thereby reducing the number of subpixels with mid-tone luminance values. The subpixel data is preferably processed within a portion of an application-specific integrated circuit (ASIC), contained within the display module.
    Type: Application
    Filed: January 26, 2001
    Publication date: October 17, 2002
    Inventors: Paul F. Greier, Kenneth C. Ho, Richard Ian Kaufman, Steven Edward Millman, Gerhard R. Thompson, Steven L. Wright, Chai Wah Wu
  • Publication number: 20020140955
    Abstract: A method (and system) for producing a halftoned image, includes calculating errors corresponding to a plurality of different viewing conditions of a halftone image, and minimizing a function of the errors, such that the halftoned image appears as a different image under different viewing conditions. Alternatively, in another embodiment, the halftoned image appears as the same image under different viewing conditions.
    Type: Application
    Filed: January 31, 2001
    Publication date: October 3, 2002
    Inventors: Gerhard Robert Thompson, Steven Lorenz Wright, Chai Wah Wu
  • Patent number: 6397334
    Abstract: A system and method for authenticating an image of an object, include at least one identifier associated with the object, a receiver for interrogating the at least one identifier to produce identification information, a camera system for recording an image from the object including the at least one identifier, and a composite generator for encoding the identification information from the receiver along with the image acquired by the camera system, to produce composite data.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: May 28, 2002
    Assignee: International Business Machines Corporation
    Inventors: Timothy Joseph Chainer, Claude A. Greengard, Paul Andrew Moskowitz, Alejandro Gabriel Schrott, Charles P. Tresser, Robert Jacob von Gutfeld, Chai Wah Wu
  • Patent number: 6256736
    Abstract: A watermarking scheme which allows the watermarked image to be authenticated by an authentication agent without revealing the human-readable content of the image. There is disclosed an approach which combines privacy control with watermarking and authentication mechanisms. The watermark can be made to be imperceptible to humans. Public key cryptography allows the authentication agent to authenticate without being able to watermark an image.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: July 3, 2001
    Assignee: International Business Machines Corporation
    Inventors: Don Coppersmith, Frederick Cole Mintzer, Charles P. Tresser, Chai Wah Wu, Minerva Ming-Yee Yeung
  • Patent number: 6172769
    Abstract: A method and an apparatus to descreen a halftoned picture takes into account the actual distribution of black or colors on the print without the need for scanning printed images but, rather, using only the printing decision matrix and the printer characteristics. For the purpose of laser printing, or more generally for reproduction on any printing device with a limited number of printing levels, a color or grayscale image has to be transformed into an array of printing decisions at each pixel of the output image. Sometimes this array is the only available representation of the original image. One may desire to reconstitute a good approximation of the original grayscale image from this array, for instance to print the picture on a printer with different characteristics from the printer for which the array was originally prepared, or to display it on a high resolution monitor. The method and apparatus to solve this problem in a way which take precise account of printer characteristics is described.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: January 9, 2001
    Assignee: International Business Machines Corporation
    Inventors: Ravishankar Rao, Gerhard Robert Thompson, Charles Philipe Tresser, Chai Wah Wu
  • Patent number: 6115616
    Abstract: A detachable keyboard for a telephone set is provided in the form of a keyboard card clipped to the headset, which is completely detached from the body when unclipped. Wireless communication between the handset body and keyboard is used when the card is unclipped, while contacts are activated in the clipped position so that the wireless handset then functions as in the case of a non detachable keyboard.
    Type: Grant
    Filed: May 28, 1998
    Date of Patent: September 5, 2000
    Assignee: International Business Machines Corporation
    Inventors: Arnold Halperin, Joseph D. Rutledge, Alejandro Gabriel Schrott, Charles P. Tresser, Robert Jacob von Gutfeld, Chai Wah Wu
  • Patent number: 6101001
    Abstract: A system and method to print grey scale or color images using fewer colors of ink than in the original image. This method distributes the error made at each point (due to the embodied approximation) to the neighbors of that point while obtaining some chosen predetermined patterns for several colors kor grey levels. Getting these predetermined patterns and essentially predetermined patterns for all colors in turn reduces the anisotropic algorithmic artifacts, suppresses edge over-enhancement and allows for good performances on patches of uniform and almost uniform colors or grey levels.
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: August 8, 2000
    Assignee: International Business Machines Corporation
    Inventors: Charles Philippe Tresser, Chai Wah Wu
  • Patent number: 6088123
    Abstract: A method and apparatus for halftoning utilizes a truly aperiodic mask with memory requirements much smaller than the mask itself. The mask is constructed of several smaller compatible masks and a selector which selects between the smaller masks. In this way the computation of a large aperiodic mask is replaced by the computation of several much smaller masks. Using this technique, watermarks may be embedded for encrypting information in such a way that the quality of the image is not compromised.
    Type: Grant
    Filed: November 21, 1997
    Date of Patent: July 11, 2000
    Assignee: International Business Machines Corporation
    Inventors: Roy Lee Adler, Gerhard Robert Thompson, Charles P. Tresser, Chai Wah Wu
  • Patent number: 6069955
    Abstract: A visible seal or label containing a serial number is placed in plain view on the product packaging. The visible label contains the serial number as well as a first public key encrypted version of the serial number. A second or hidden label inside of the package has thereon a second a second encrypted version of the serial number made using a second public key. The hidden label may be secured inside of the package out of sight or may be placed on the back of the visible label and therefore viewable through a transparent case when opened or visible when peeled off. The private keys are known only to the manufacturer. Using a corresponding public key provided by the manufacturer, the consumer, law enforcement agent, or customs inspector can verify that the encrypted version matches the serial number. An advantage to this method is that only the manufacturer can produce matching pairs.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: May 30, 2000
    Assignee: International Business Machines Corporation
    Inventors: Don Coppersmith, Claude A. Greengard, Charles P. Tresser, Chai Wah Wu
  • Patent number: 6064701
    Abstract: An alternative to classical spread spectrum communication systems is based on synchronization of dynamical systems which can resist noisy transmission channels, jamming, gain modulation, multiple time delays, and self-jamming.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: May 16, 2000
    Assignee: International Business Machines Corporation
    Inventors: Charles Philippe Tresser, Chai Wah Wu