Patents by Inventor G. V. Varaprasad

G. V. Varaprasad 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: 10025988
    Abstract: A video noise analyzer for detecting residual point noise in a video generates a list of candidate defective pixels by joining results of a temporal invariance detector and a spatial outlier detector. A data store is structured to contain data describing the candidate defective pixels and/or the blocks from which the pixels were selected. In other embodiments, a video noise analyzer includes a first salient analyzer structured to compare pixels within a block to a mean value of other pixels within the same block, a first threshold processor to generate a first pixel candidate list including pixels that differ significantly from their neighboring pixels, a second salient analyzer structured to generate a difference value between a subject pixel, its neighboring pixels, and neighbors of the neighboring pixels, and an identifier to label as a candidate dead pixel those pixels having a frequency occurrence of visual saliency greater than a predefined frequency threshold.
    Type: Grant
    Filed: September 8, 2015
    Date of Patent: July 17, 2018
    Assignee: Tektronix, Inc.
    Inventors: Jie Yuan, Onkar Nath Tiwari, Arvind Nayak, G. V. Varaprasad
  • Publication number: 20160342843
    Abstract: A video noise analyzer for detecting residual point noise in a video generates a list of candidate defective pixels by joining results of a temporal invariance detector and a spatial outlier detector. A data store is structured to contain data describing the candidate defective pixels and/or the blocks from which the pixels were selected. In other embodiments, a video noise analyzer includes a first salient analyzer structured to compare pixels within a block to a mean value of other pixels within the same block, a first threshold processor to generate a first pixel candidate list including pixels that differ significantly from their neighboring pixels, a second salient analyzer structured to generate a difference value between a subject pixel, its neighboring pixels, and neighbors of the neighboring pixels, and an identifier to label as a candidate dead pixel those pixels having a frequency occurrence of visual saliency greater than a predefined frequency threshold.
    Type: Application
    Filed: September 8, 2015
    Publication date: November 24, 2016
    Inventors: Jie Yuan, Onkar Nath Tiwari, Arvind Nayak, G.V. Varaprasad
  • Patent number: 9148644
    Abstract: Methods for detecting structured artifacts in a video may begin by accepting a video frame at a video input and then generating a filtered frame from the video frame. After a differenced image is produced, groups of connected pixels (blobs) within the differenced frame are identified, and isolated blobs are removed to produce a cleaned image. A Fourier transform is performed on the cleaned image, and structured artifacts may be identified based on a comparison of magnitudes of the Fourier components of the cleaned image. Devices that detect and identify structured artifacts are also described.
    Type: Grant
    Filed: December 13, 2013
    Date of Patent: September 29, 2015
    Assignee: TEKTRONIX, INC.
    Inventors: Arvind Nayak, G. V. Varaprasad
  • Publication number: 20140169763
    Abstract: Methods for detecting structured artifacts in a video may begin by accepting a video frame at a video input and then generating a filtered frame from the video frame. After a differenced image is produced, groups of connected pixels (blobs) within the differenced frame are identified, and isolated blobs are removed to produce a cleaned image. A Fourier transform is performed on the cleaned image, and structured artifacts may be identified based on a comparison of magnitudes of the Fourier components of the cleaned image. Devices that detect and identify structured artifacts are also described.
    Type: Application
    Filed: December 13, 2013
    Publication date: June 19, 2014
    Applicant: Tektronix, Inc.
    Inventors: Arvind Nayak, G. V. Varaprasad
  • Patent number: 7671856
    Abstract: A unique test pattern is used for measuring timing parameters of RGBHV analog video signals. For horizontal timing a horizontal line includes within an active video region left and right portions at a first level and a central portion at a second level, the left, right and central portions having a defined percentage relationship to the number of pixels of the horizontal line within the active video region. Also optionally included are left and right border portions just prior to and just after the left and right portions respectively. Measurements are done in pixels for the horizontal line from a horizontal sync pulse to each transition of the unique test pattern, and the horizontal timing parameters are derived from such measurements.
    Type: Grant
    Filed: January 3, 2005
    Date of Patent: March 2, 2010
    Assignee: Tektronix, Inc.
    Inventors: G. V. Varaprasad, Anindya Dutta