Patents by Inventor Xuemei Zhang

Xuemei Zhang 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: 20060256215
    Abstract: An image processing system subtracts dark noise out of images based on a dark noise scale factor. The image processing system includes an image sensor for capturing a current image and producing current image data representing the current image. The current image data includes both a dark noise signal and an image signal. The dark noise scale factor for the current image is estimated from the current image data and reference image data representing a reference dark noise signal. The reference dark noise signal is scaled by the dark noise scale factor to produce a scaled dark noise signal from which the current image data is subtracted to produce the image signal.
    Type: Application
    Filed: May 16, 2005
    Publication date: November 16, 2006
    Inventors: Xuemei Zhang, Richard Baer, Dietrich Vook
  • Publication number: 20060244476
    Abstract: Defect mitigation in display panels. Defects in a display panel are mapped, and the defect information is associated with the display system or associated with the panel. During panel operation, the values of pixels neighboring defective pixels are altered to minimize their visibility to the observer. In a first model, luminance error caused by a defect is compensated by adjust neighboring pixels. In a second model, Error in luminance and one of the two chrominance channels is compensated by adjusting neighboring pixels. The defect mitigation methods seek to shift the errors introduced by defective pixels into high spatial frequency elements and chromatic elements, which the human eye is not sensitive to.
    Type: Application
    Filed: April 28, 2005
    Publication date: November 2, 2006
    Inventors: Xuemei Zhang, Feng Xiao
  • Patent number: 7079705
    Abstract: An image processing system and demosaicing method are provided to calculate estimated missing color sensor values in an image using a linear prediction from the raw color sensor value at the current pixel location. The raw image is divided into regions of sensor values, and the linear relations between color planes for each region are determined by a regression method that calculates the degree to which different color planes co-vary within each region The missing color sensor values per region are calculated as a scaled and shifted version of the raw color sensor values using linear regression coefficients determined from the local linear regression process.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: July 18, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Xuemei Zhang, Ramakrishna Kakarala, Todd S. Sachs
  • Publication number: 20060126127
    Abstract: A digital image sensor comprising an array of pixels and a processor is provided. The array of pixels comprises a current pixel in a first color plane that is configured to produce a current sensor value, a first plurality of pixels in the first color plane that is configured to produce a first plurality of sensor values, and a second plurality of pixels in the second color plane that is configured to produce a second plurality of sensor values. The processor is configured to generate a plurality of estimate values using the first plurality of sensor values and a plurality of intensity ratios associated with the second plurality of sensor values, and the processor is configured to determine whether the current pixel is defective using the plurality of estimate values and the current sensor value.
    Type: Application
    Filed: December 9, 2004
    Publication date: June 15, 2006
    Inventors: John Stanback, Xuemei Zhang, Ramakrishna Kakarala, Bond Ying
  • Publication number: 20060092171
    Abstract: Difference values between selected pixels pairs in the same color plane are determined for each color plane of an image. The pixel pairs may include contiguous or non-contiguous pixels. A statistic based on the pixel difference values of each color plane is then used to estimate the white point.
    Type: Application
    Filed: November 1, 2004
    Publication date: May 4, 2006
    Inventor: Xuemei Zhang
  • Publication number: 20060085873
    Abstract: Transgenic plant cell lines and the plant cell expression systems which express HBsAg. The present invention further relates to the method of preparing the above-mentioned cell lines or expression systems, and the use of the above-mentioned cell lines or expression systems in the manufacture of HBsAg protein. The cell lines or expression systems disclosed in the invention can be used to prepare vaccine against hepatitis B virus.
    Type: Application
    Filed: September 26, 2005
    Publication date: April 20, 2006
    Inventors: Jun Sheng, Dan Liu, Xiaoyu Liu, Qiao Guo, Haipeng Yu, Juan Li, Yuejun Hui, Zhiwu Wang, Xuemei Zhang
  • Patent number: 7023580
    Abstract: An adaptive image tone mapping curve based on perceptual preference guidelines is generated as a sigmoidal function, in which the sigmoidal function parameters (slope and shift) are determined by original image statistics. Tone curves generated for different images each have a smooth sigmoidal shape, so that the tone mapping process does not change the image histogram shape drastically. The sigmoidal function has the form: t ? ( x ) = 100 1 + exp ? ( - ? ? ( x / 100 - ? ) ) , where ? is the slope parameter and ? is the shift parameter. The input value x in the sigmoidal function varies in the range [0, 100], because the tone curve is generated on an L* scale, which has values from 0 to 100.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: April 4, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Xuemei Zhang, Robert W. Jones, Izhak Baharav, Donald M. Reid
  • Patent number: 7019826
    Abstract: A three-dimensional optical inspection system reconstructs a three-dimensional image of the shape of the surface of an at least partially specular object resident on a printed circuit board by capturing two or more two-dimensional images of the object under different illumination configurations. The diffuse reflection, as well as the specular reflection can be used to reconstruct the three-dimensional image using any reconstruction method, such as photometric stereo. The different illumination configurations can be achieved using an illumination source including light-emitting elements arranged in concentric circular arrays, in which each of the circular arrays is divided into sections. Each section is independently controlled to selectively activate the sections to illuminate the object in a pre-established illumination pattern.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: March 28, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Dietrich W. Vook, Izhak Baharav, Xuemei Zhang, Ramakrishna Kakarala, Richard L. Baer
  • Publication number: 20060044276
    Abstract: An a data input system includes an encoded pad having position encoding and a data input device adapted to image a portion of the encoded pad to determine position and orientation of the data input device relative to the encoded pad. The encoding pad includes a plurality of correlation windows. Each correlation window includes a primary encoding marker in form of vertical line segment and a set of secondary encoding markers in form of diagonal line segments, at least one diagonal line segment intersecting the vertical line segment at an intersection angle. Spacing of the diagonal line segments encodes the X-axis position of the input device relative to the encoding pad. Intersection angle encodes the Y-axis position of the input device relative to the encoding pad. Angle of the primary encoding marker vertical line segment within the frame of the captured image encodes the angular orientation of the input device relative to the axes of the encoded pad.
    Type: Application
    Filed: June 17, 2004
    Publication date: March 2, 2006
    Inventors: Richard Baer, Ramakrishna Kakarala, Dietrich Vook, Xuemei Zhang, Izhak Baharav, Paul Corredoura
  • Publication number: 20060032726
    Abstract: A coin inspection system including a coin passageway, an illumination apparatus to illuminate at least one coin positioned on the coin passageway, a sensing apparatus positioned to receive light reflected from the coin and a processing apparatus to reconstruct a three-dimensional image of the coin based on the reflected light.
    Type: Application
    Filed: August 10, 2004
    Publication date: February 16, 2006
    Inventors: Dietrich Vook, Richard Baer, Xuemei Zhang, S. Rosner, Izhak Baharav
  • Patent number: 6894720
    Abstract: A pixel of a digital image is processed by applying a tone mapping function to a first color channel of the pixel, whereby a value of the first color channel is changed by a scale factor; and applying the scale factor to all other color channels of the pixel. The first color channel most closely matches relative luminance response of the human visual system.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: May 17, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Xuemei Zhang
  • Patent number: 6864911
    Abstract: A system of linked digital cameras for an image capture system is disclosed. A first and second digital camera can be linked to capture a first images and a second image that are used to form a stereo image. A first data port on the first digital camera and a second data port on the second digital camera intercommunicate data between each other when the cameras are linked. The data can include the first and second image data, camera control data, and camera synchronization data. After capturing the first and second images, the image from one of the cameras can be transferred to the other camera so that both the first and second images reside in the other camera. The system allows a user who wishes to capture stereo images the ability to do so with out having to purchase two digital cameras. A compatible digital camera can be borrowed from another user for the purpose of stereo image capture. After the stereo image is captured, the user transfers both images to his camera and returns the borrowed camera.
    Type: Grant
    Filed: October 26, 2000
    Date of Patent: March 8, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Xuemei Zhang, Yingmei Lavin
  • Publication number: 20050015683
    Abstract: A method and system for improving the reliability of a system, such as a software system, is disclosed. “Service measurements” that are routinely measured and monitored in connection with the operation of systems (e.g., QOS (Quality Of Service) measurements) are utilized in the reliability architecture of the system. Service measurements include a number of alternative data types, such as transactions completed, messages received, messages sent, calls completed, bytes transmitted, jobs processed, etc. Any operations of the system that are typically monitored for other purposes can be utilized in the reliability architecture of the present invention. Most systems track these types of statistics as, for example, part of their billing procedures or part of their performance bench-marking or QOS processes.
    Type: Application
    Filed: July 16, 2003
    Publication date: January 20, 2005
    Applicant: Lucent Technologies Inc.
    Inventors: James Clark, Daniel Jeske, Omar Salvador, Kazem Sohraby, Xuemei Zhang
  • Publication number: 20040218072
    Abstract: A pixel of a digital image is processed by applying a tone mapping function to a first color channel of the pixel, whereby a value of the first color channel is changed by a scale factor; and applying the scale factor to all other color channels of the pixel. The first color channel most closely matches relative luminance response of the human visual system.
    Type: Application
    Filed: August 30, 2001
    Publication date: November 4, 2004
    Inventor: Xuemei Zhang
  • Publication number: 20040184653
    Abstract: An optical inspection system uses an illumination gradient to gradually spatially vary the intensity and/or specular characteristics of the illumination reflected from the surface of a specular object to determine surface gradients of the object. The surface gradients can be used to reconstruct a three-dimensional image of the object. The illumination gradient can be produced by an illumination apparatus that includes circular arrays of light-emitting elements. The illumination gradient can also be produced using an optical element that gradually alters the illumination intensity of the reflected illumination in accordance with the incidence characteristics of the reflected illumination on the optical element. The illumination gradient enables the use of numerous illumination angles to reduce error in estimated surface gradients without increasing imaging or processing time.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: Richard L. Baer, Xuemei Zhang, Dietrich W. Vook
  • Publication number: 20040184031
    Abstract: A three-dimensional optical inspection system reconstructs a three-dimensional image of the shape of the surface of an at least partially specular object resident on a printed circuit board by capturing two or more two-dimensional images of the object under different illumination configurations. The diffuse reflection, as well as the specular reflection can be used to reconstruct the three-dimensional image using any reconstruction method, such as photometric stereo. The different illumination configurations can be achieved using an illumination source including light-emitting elements arranged in concentric circular arrays, in which each of the circular arrays is divided into sections. Each section is independently controlled to selectively activate the sections to illuminate the object in a pre-established illumination pattern.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: Dietrich W. Vook, Izhak Baharav, Xuemei Zhang, Ramakrishna Kakarala, Richard L. Baer
  • Publication number: 20040184032
    Abstract: A display for use in a printed circuit board inspection system for inspecting objects on a printed circuit board is capable of displaying a greater-than-two dimensional image of the shape of the surface of an object resident on the printed circuit board in at least two dimensions. The image of the object is generated based on optical imaging of the object under different illumination configurations.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: James Mahon, S. Jeffrey Rosner, Izhak Baharav, Xuemei Zhang
  • Publication number: 20040184648
    Abstract: Reconstructing the shape of the surface of an object in greater than two dimensions is performed using a noise-tolerant reconstruction process and/or a multi-resolution reconstruction process. The noise-tolerant reconstruction process can be a Bayesian reconstruction process that adds noise information representing the noise distribution in optical image(s) of the object to surface gradient information estimated from the images to determine surface height information that defines the shape of the surface of the object in greater than two dimensions. In the multi-resolution reconstruction process, for each resolution of the image, the surface gradient information is estimated and the surface height information is calculated using the estimated surface gradient information. To obtain the final surface height map, the surface height information from each resolution is combined to reconstruct the shape of the surface of the object in greater than two dimensions.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: Xuemei Zhang, Ramakrishna Kakarala, Izhak Baharav
  • Publication number: 20040160420
    Abstract: Electronic devices having image-based data input systems are described. In one aspect, an electronic device includes a window, multiple indicia, an image sensor, and a data input processor. The window has a contact surface with an input region. The multiple indicia are viewable in the input region of the contact surface. The image sensor is constructed and arranged to produce image signals corresponding to images of the input region. The data input processor is coupled to the image sensor and is operable to produce input signals based on image signals produced by the image sensor and a mapping between areas of the input region images and locations of the input indicia.
    Type: Application
    Filed: February 19, 2003
    Publication date: August 19, 2004
    Inventors: Izhak Baharav, Russell M. Iimura, Xuemei Zhang, Dietrich W. Vook, Ramakrishna Kakarala
  • Patent number: 6737625
    Abstract: A sensor includes an array of photodetectors each generating an output signal of pixel data indicative of incident light intensity. This pixel data is read out from the array one line at a time and stored in a line buffer. A bad pixel processor includes a first buffer that stores pixel data obtained from the line buffer for a certain pixel in a currently read out line and pixel signal light data for pixels adjacent to the certain pixel.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: May 18, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Izhak Baharav, Ramakrishna Kakarala, Xuemei Zhang, Dietrich Werner Vook