Patents by Inventor Ramakrishna Kakarala

Ramakrishna Kakarala 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: 20060108503
    Abstract: A spatial filter includes a number of photodetectors that generate individual signals in the time domain. The individual signals are subsequently divided and grouped to create the I and Q channels output from the spatial filter. Prior to the formation of the I and Q channels, a window function is used to shape the spatial response of the spatial filter.
    Type: Application
    Filed: November 19, 2004
    Publication date: May 25, 2006
    Inventors: Stephan Hengstler, Ramakrishna Kakarala
  • 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
  • Patent number: 7015961
    Abstract: A digital image system and method for combining bad pixel correction and demosaicing in a single process is provided by interpolating sensor values for pixels immediately spatially adjacent to the current pixel being examined to detect defective pixels, and using the interpolated values for demosaicing. If the sensor value of the current pixel being examined is outside of a range of sensor values determined from the interpolated values by more than a configurable threshold amount, the current pixel is considered defective, and replaced using an estimated value from the neighboring pixels.
    Type: Grant
    Filed: August 16, 2002
    Date of Patent: March 21, 2006
    Inventor: Ramakrishna Kakarala
  • 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: 20060033014
    Abstract: An optical navigation system, e.g. optical mouse, determines optical navigation quality by examining some or all of the photosensors of a frame or monitoring intermediate or final results of the motion estimation system. The optical navigation quality is then used to determine the navigation output produced by the optical navigation system.
    Type: Application
    Filed: August 13, 2004
    Publication date: February 16, 2006
    Inventors: David Feldmeier, Ramakrishna Kakarala, John Wenstrand
  • Patent number: 6989862
    Abstract: A system and method for processing mosaiced or raw data images operates to concurrently demosaic and resize the mosaiced images in a combined process. The combined demosaic/resize process allows the system to perform demosaicing and resizing more efficiently than conventional systems, which perform these processes separately and sequentially. Furthermore, the combined demosaic/resize process allows the system to produce demosaiced and resized images of higher quality as compared to demosaiced and resized images produced by the conventional systems.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: January 24, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Izhak Baharav, Ramakrishna Kakarala, Dietrich W. Vook
  • Publication number: 20050206614
    Abstract: An apparatus for controlling the position of a screen pointer includes an at least partially coherent light source for illuminating an imaging surface, thereby generating reflected images. The apparatus includes a navigation sensor for generating digital images based on the reflected images, performing a movement computation based on the digital images, generating movement data based on the movement computation that is indicative of relative motion between the imaging surface and the apparatus, wherein the movement computation has a low sensitivity to effects in the digital images caused by particle contamination.
    Type: Application
    Filed: March 22, 2004
    Publication date: September 22, 2005
    Inventors: Michael Brosnan, Ramakrishna Kakarala, Roopinder Grewal, Mark Butterworth, Vincent Moyer, Tong Xie, Marshall Depue
  • Publication number: 20050195163
    Abstract: An apparatus for controlling the position of a screen pointer includes a light source for illuminating an imaging surface, thereby generating reflected images. The apparatus includes a navigation sensor for generating digital images based on the reflected images, detecting defective pixel locations in the digital images, and generating movement data based on the digital images that is indicative of relative motion between the imaging surface and the apparatus.
    Type: Application
    Filed: March 8, 2004
    Publication date: September 8, 2005
    Inventors: Roopinder Grewal, Ramakrishna Kakarala
  • Publication number: 20050083303
    Abstract: A system, method, and device for tracking motion across a surface by creating an interference pattern by reflecting light from the surface. There is produced, as a result of sensor moving across the surface, at least one signal pattern corresponding to a detection of a dimension of the interference pattern. This detected dimension is associated with an assumed dimensional value to determine a distance traveled by the sensor.
    Type: Application
    Filed: October 16, 2003
    Publication date: April 21, 2005
    Inventors: Dale Schroeder, Marshall DePue, Ramakrishna Kakarala, Tong Xie, Gregory VanWiggeren
  • Publication number: 20050024503
    Abstract: Methods for reducing artifacts caused by illuminant flicker are provided. One such method comprises: providing pixel circuits; and operating the pixel circuits in a bi-directional mode during which first information corresponding to a scene is acquired in forward row-sequential order of the pixel circuits and then second information corresponding to the scene is acquired in a reverse row-sequential order of the pixel circuits. Systems also are provided.
    Type: Application
    Filed: July 28, 2003
    Publication date: February 3, 2005
    Inventors: Richard Baer, Ramakrishna Kakarala
  • Publication number: 20040239630
    Abstract: Feedback is provided when an optical navigation device acquires an image that is not suitable for navigation purposes. An image sensor embedded within the optical navigation device acquires an image of a surface. An image monitor determines the navigability of the captured image and generates a signal indicative of the image's navigability. A comparator compares the signal to a threshold navigability level. When the image navigability is determined to be below the threshold and thus non-navigable, the comparator asserts a feedback signal. The feedback signal may trigger a variety of feedback mechanisms to alert the user that the surface is non-navigable. Possible feedback mechanisms include a warning message on a display screen, an illuminated light on the optical navigation device, or an audible sound.
    Type: Application
    Filed: May 30, 2003
    Publication date: December 2, 2004
    Inventors: Ramakrishna Kakarala, Roopinder Singh Grewal, Vincent C. Moyer
  • Patent number: 6819801
    Abstract: A system and method is provided for processing a demosaiced image using a color aliasing artifact reduction (CAAR) algorithm in order to reduce color aliasing artifacts. The CAAR algorithm computes the L level wavelet transform for the demosaiced color planes R, G and B. Thereafter, the CAAR algorithm estimates the correct color value at each pixel location for the colors not associated with that pixel location. For example, to determine the green value at red pixel locations, the CAAR algorithm performs an inverse wavelet transform using the green approximation signal and the red detail signals. This process is repeated for each of the colors (e.g., green values at blue pixel locations, red values at green pixel locations, etc.). In addition, the CAAR algorithm performs an inverse wavelet transform on each of the color planes themselves, so that the pixel values of the color associated with each pixel location are not altered.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: November 16, 2004
    Assignee: Agilent Technologies, Inc.
    Inventors: Ramakrishna Kakarala, Izhak Baharav
  • Publication number: 20040201721
    Abstract: A system and method for processing mosaiced or raw data images operates to concurrently demosaic and resize the mosaiced images in a combined process. The combined demosaic/resize process allows the system to perform demosaicing and resizing more efficiently than conventional systems, which perform these processes separately and sequentially. Furthermore, the combined demosaic/resize process allows the system to produce demosaiced and resized images of higher quality as compared to demosaiced and resized images produced by the conventional systems.
    Type: Application
    Filed: August 23, 2001
    Publication date: October 14, 2004
    Inventors: Izhak Baharav, Ramakrishna Kakarala, 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: 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
  • Publication number: 20040146217
    Abstract: A repetitive surface detector includes an image capture device capturing an image. An autocorrelator receives the image and generates a signal indicative of a repetitive background of the image. A controller determines a maximum and minimum value in the auto-correlated signal. An adder determines the signed difference between the maximum and minimum value. A comparator compares the signed difference with a threshold and generates an output that indicates when the image includes a repetitive background.
    Type: Application
    Filed: January 23, 2003
    Publication date: July 29, 2004
    Inventors: Ramakrishna Kakarala, Michael John Brosnan
  • 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
  • Publication number: 20040086177
    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: Application
    Filed: October 30, 2002
    Publication date: May 6, 2004
    Inventors: Xuemei Zhang, Ramakrishna Kakarala, Todd S. Sachs
  • Publication number: 20040086152
    Abstract: A system and method is provided for event detection for video surveillance systems using a compressed prior image. Transform coefficients for a current image are computed and compared to transform coefficients representing the prior image. A determination is made whether a change has occurred sufficient to cause the detection of an event based on the results of the comparison.
    Type: Application
    Filed: October 30, 2002
    Publication date: May 6, 2004
    Inventors: Ramakrishna Kakarala, Kevin W. Tibbs, Dietrich Vook