Xuemei L Zhang from Mountain View, CA, age 56

Us Patents

Method And Apparatus For Estimating True Color Values For Saturated Color Values In Digitally Captured Image Data
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US Patent:

6731794, May 4, 2004
Filed:

Apr 12, 2001
Appl. No.:

09/834807
Inventors:

Xuemei Zhang - Mountain View CA
David H Brainard - Santa Barbara CA
Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX
International Classification:

G06K 900
US Classification:

382165, 382272, 382274, 358520
Abstract:

A system and method of adjusting a saturated color value in a digital color image by estimating a true color value for the saturated color value using a statistical technique where a prior statistical distribution of color values representing the probability of captured responses of an image capture device is used to determine a posterior distribution of possible true color values for the saturated color values. The method is preformed by obtaining a first statistical distribution of color values associated with all pixel locations in the digital image that represents captured responses of an image capture device. A saturated color value of a first color component and its location is detected in the digital data. Based on the other color component color values at the detected location, a second statistical distribution is derived from the first distribution that represents a distribution of possible true color values for the detected saturated color value. The mean of the second distribution provides an estimation of the true color value for adjusting the detected saturated color value.

Bad Pixel Detection And Correction In An Image Sensing Device
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US Patent:

6737625, May 18, 2004
Filed:

Jun 28, 2001
Appl. No.:

09/895627
Inventors:

Izhak Baharav - San Jose CA
Ramakrishna Kakarala - Sunnyvale CA
Xuemei Zhang - Mountain View CA
Dietrich Werner Vook - Menlo Park CA
Assignee:

Agilent Technologies, Inc. - Palo Alto CA
International Classification:

H04N 5335
US Classification:

2502081, 3482301, 348615
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.

Linkable Digital Cameras For An Image Capture System
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US Patent:

6864911, Mar 8, 2005
Filed:

Oct 26, 2000
Appl. No.:

09/696779
Inventors:

Xuemei Zhang - Mountain View CA, US
Yingmei Lavin - Newark CA, US
Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX
International Classification:

H04N015/00
H04N005/232
US Classification:

348 42, 348 46, 3482111
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.

Method And Apparatus For Applying Tone Mapping Functions To Color Images
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US Patent:

6894720, May 17, 2005
Filed:

Aug 30, 2001
Appl. No.:

09/945094
Inventors:

Xuemei Zhang - Mountain View CA, US
Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX
International Classification:

H04N005/228
H04N009/68
H04N003/14
G03F003/08
G06K009/00
US Classification:

3482221, 348234, 348273, 382167, 358520
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.

Optical Inspection System, Apparatus And Method For Reconstructing Three-Dimensional Images For Printed Circuit Board And Electronics Manufacturing Inspection
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US Patent:

7019826, Mar 28, 2006
Filed:

Mar 20, 2003
Appl. No.:

10/392990
Inventors:

Dietrich W. Vook - Los Altos CA, US
Izhak Baharav - San Jose CA, US
Xuemei Zhang - Mountain View CA, US
Ramakrishna Kakarala - Santa Clara CA, US
Richard L. Baer - Los Altos CA, US
Assignee:

Agilent Technologies, Inc. - Palo Alto CA
International Classification:

G01N 21/00
G01N 21/88
G06K 9/00
US Classification:

3562371, 3562374, 25055934, 382150
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.

System And Method For Digital Image Tone Mapping Using An Adaptive Sigmoidal Function Based On Perceptual Preference Guidelines
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US Patent:

7023580, Apr 4, 2006
Filed:

Apr 20, 2001
Appl. No.:

09/839335
Inventors:

Xuemei Zhang - Mountain View CA, US
Robert W. Jones - Corvallis OR, US
Izhak Baharav - San Jose CA, US
Donald M. Reid - Corvallis OR, US
Assignee:

Agilent Technologies, Inc. - Palo Alto CA
International Classification:

H04N 1/407
H04N 1/56
G06T 5/40
US Classification:

358 19, 358 321, 358519, 358521, 358522, 382169
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: where α is the slope parameter and β 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. The sigmoidal tone curve calculation can be implemented efficiently using simple arithmetic operations by pre-calculating and storing various factors used in the calculation of α and β and by pre-generating a pair of fixed tone curves with two extreme slopes and interpolating between the curves.

Color Interpolation For Image Sensors Using A Local Linear Regression Method
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US Patent:

7079705, Jul 18, 2006
Filed:

Oct 30, 2002
Appl. No.:

10/284696
Inventors:

Xuemei Zhang - Mountain View CA, US
Ramakrishna Kakarala - Sunnyvale CA, US
Todd S. Sachs - Palo Alto CA, US
Assignee:

Agilent Technologies, Inc. - Palo Alto CA
International Classification:

G06K 9/00
G06K 9/32
G06K 9/36
H04N 1/46
US Classification:

382280, 382162, 382300, 358525
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.

Optical Inspection System And Method For Displaying Imaged Objects In Greater Than Two Dimensions
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US Patent:

7171037, Jan 30, 2007
Filed:

Mar 20, 2003
Appl. No.:

10/393413
Inventors:

James Mahon - Dublin, IE
S. Jeffrey Rosner - Palo Alto CA, US
Izhak Baharav - San Jose CA, US
Xuemei Zhang - Mountain View CA, US
Assignee:

Agilent Technologies, Inc. - Santa Clara CA
International Classification:

G06K 9/00
G06K 9/68
US Classification:

382145, 382154, 382218
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.