Patents by Inventor Ravi K. Sharma

Ravi K. Sharma 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: 9953390
    Abstract: Signal processing devices and methods estimate transforms between signals using a least squares technique. From a seed set of transform candidates, a direct least squares method applies a seed transform candidate to a reference signal and then measures correlation between the transformed reference signal and a suspect signal. For each candidate, update coordinates of reference signal features are identified in the suspect signal and provided as input to a least squares method to compute an update to the transform candidate. The method iterates so long as the update of the transform provides a better correlation. At the end of the process, the method identifies a transform or set of top transforms based on a further analysis of correlation, as well as other results.
    Type: Grant
    Filed: November 9, 2015
    Date of Patent: April 24, 2018
    Assignee: Digimarc Corporation
    Inventors: Ravi K. Sharma, John D. Lord, Robert G. Lyons
  • Patent number: 9928560
    Abstract: The present invention relate generally to signal encoding and decoding.
    Type: Grant
    Filed: May 25, 2017
    Date of Patent: March 27, 2018
    Assignee: Digimarc Corporation
    Inventors: Alastair M. Reed, Ravi K. Sharma
  • Patent number: 9891883
    Abstract: Methods and arrangements involving electronic devices, such as smartphones, tablet computers, wearable devices, etc., are disclosed. One arrangement involves a low-power processing technique for discerning cues from audio input. Another involves a technique for detecting audio activity based on the Kullback-Liebler divergence (KLD) (or a modified version thereof) of the audio input. Still other arrangements concern techniques for managing the manner in which policies are embodied on an electronic device. Others relate to distributed computing techniques. A great variety of other features are also detailed.
    Type: Grant
    Filed: June 24, 2016
    Date of Patent: February 13, 2018
    Assignee: Digimarc Corporation
    Inventors: Ravi K. Sharma, Shankar Thagadur Shivappa, Osama M. Alattar, Brett A. Bradley, Scott M. Long, Ajith M. Kamath, Vojtech Holub, Hugh L. Brunk, Robert G. Lyons, Aparna R. Gurijala
  • Publication number: 20180005341
    Abstract: The present invention relate generally to signal encoding and decoding.
    Type: Application
    Filed: May 25, 2017
    Publication date: January 4, 2018
    Inventors: Alastair M. Reed, Ravi K. Sharma
  • Publication number: 20180005343
    Abstract: A steganographic digital watermark signal is decoded from host imagery without requiring a domain transformation for signal synchronization, thereby speeding and simplifying the decoding operation. In time-limited applications, such as in supermarket point-of-sale scanners that attempt watermark decode operations on dozens of video frames every second, the speed improvement allows a greater percentage of each image frame to be analyzed for watermark data. In battery-powered mobile devices, avoidance of repeated domain transformations extends battery life. A great variety of other features and arrangements, including machine learning aspects, are also detailed.
    Type: Application
    Filed: July 3, 2017
    Publication date: January 4, 2018
    Inventors: Geoffrey B. Rhoads, Tony F. Rodriguez, Eric D. Evans, Ravi K. Sharma, Tomas Filler, Vahid Sedighianaraki
  • Patent number: 9852736
    Abstract: Audio signal processing enhances audio watermark embedding and detecting processes. Audio signal processes include audio classification and adapting watermark embedding and detecting based on classification. Advances in audio watermark design include adaptive watermark signal structure data protocols, perceptual models, and insertion methods. Perceptual and robustness evaluation is integrated into audio watermark embedding to optimize audio quality relative the original signal, and to optimize robustness or data capacity. These methods are applied to audio segments in audio embedder and detector configurations to support real time operation. Feature extraction and matching are also used to adapt audio watermark embedding and detecting.
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: December 26, 2017
    Assignee: Digimarc Corporation
    Inventors: Ravi K. Sharma, Brett A. Bradley, Yang Bai, Shankar Thagadur Shivappa, Ajith Kamath, Aparna Gurijala, David A. Cushman
  • Patent number: 9842163
    Abstract: This disclosure describes a distributed reader architecture for a mobile computing device such as cellular telephone handset.
    Type: Grant
    Filed: April 25, 2016
    Date of Patent: December 12, 2017
    Assignee: Digimarc Corporation
    Inventors: Ravi K. Sharma, Tony F. Rodriguez
  • Publication number: 20170345126
    Abstract: A phase deviation method determines an offset between a reference and suspect signal by analyzing a phase deviation surface created by computing a deviation metric for phase shift and then analyzing a surface formed from the deviation metrics for an array of offsets. The phase deviation method analyzes the deviation surface to determine an offset that minimizes phase deviation. This method is applied at increasing levels of detail to refine the determination of the offset.
    Type: Application
    Filed: May 15, 2017
    Publication date: November 30, 2017
    Inventors: Ravi K. Sharma, John D. Lord
  • Patent number: 9832353
    Abstract: The disclosure relates to digital watermarking, steganography, and specifically to message coding protocols used in conjunction with digital watermarking and steganographic encoding/decoding and payload interpretation methods. One claim recites a method for interpreting a data structure having fixed and variable message portions, the method comprising: processing the fixed message portion to determine a version of the variable message portion; decoding the entire payload field of the variable message portion according to the determined version; and interpreting only a portion of the decoded payload field according to the determined version. Of course, other features and claims are provided too.
    Type: Grant
    Filed: February 2, 2015
    Date of Patent: November 28, 2017
    Assignee: Digimarc Corporation
    Inventors: Matthew M. Weaver, Ravi K. Sharma
  • Patent number: 9819950
    Abstract: There are many advantages to implementing a watermark-based system using dedicated hardware, rather than using software executing on a general purpose processor. These include higher speed and lower power consumption. However, hardware implementations incur substantial design and development costs. Moreover, because each watermarking application has its own design constraints and parameters, it has not been cost-effective to develop a hardware chip design for each, since such chips would typically not be manufactured in volumes sufficient to bring per-unit costs down to an acceptable level. The present technology provides various techniques for making watermarking hardware adaptable, so that a single chip can serve multiple diverse watermark applications. By so-doing, the advantages of hardware implementation are made available where it was formerly cost-prohibitive, thereby enhancing operation of a great variety of watermark-based systems.
    Type: Grant
    Filed: September 1, 2015
    Date of Patent: November 14, 2017
    Assignee: Digimarc Corporation
    Inventors: Jacob L. Boles, Ravi K. Sharma, John D. Lord
  • Patent number: 9811757
    Abstract: A multidimensional histogram is used to characterize an image (or object), and is used to identify candidate matches with one or more reference images (or objects). An exemplary implementation employs hue information for two of the dimensions, and a second derivative function based on luminance for a third dimension. The simplicity and speed of the detailed arrangements make them well suited for use with cell phones and other mobile devices, which can use the technology for image/object recognition, e.g., in visual search applications.
    Type: Grant
    Filed: August 1, 2016
    Date of Patent: November 7, 2017
    Assignee: Digimarc Corporation
    Inventor: Ravi K. Sharma
  • Patent number: 9773504
    Abstract: Spectral encoding methods are more robust when used with improved weak signal detection and synchronizations methods. Further robustness gains are achieved by using informed embedding, error correction and embedding protocols that enable signal to noise enhancements by folding and pre-filtering the received signal.
    Type: Grant
    Filed: October 10, 2016
    Date of Patent: September 26, 2017
    Assignee: Digimarc Corporation
    Inventors: Ravi K. Sharma, Adnan M. Alattar
  • Publication number: 20170236037
    Abstract: Methods and arrangements involving portable user devices such smartphones and wearable electronic devices are disclosed, as well as other devices and sensors distributed within an ambient environment. Some arrangements enable a user to perform an object recognition process in a computationally- and time-efficient manner. Other arrangements enable users and other entities to, either individually or cooperatively, register or enroll physical objects into one or more object registries on which an object recognition process can be performed. Still other arrangements enable users and other entities to, either individually or cooperatively, associate registered or enrolled objects with one or more items of metadata. A great variety of other features and arrangements are also detailed.
    Type: Application
    Filed: October 24, 2016
    Publication date: August 17, 2017
    Inventors: Geoffrey B. Rhoads, Yang Bai, Tony F. Rodriguez, Eliot Rogers, Ravi K. Sharma, John D. Lord, Scott Long, Brian T. MacIntosh, Kurt M. Eaton
  • Publication number: 20170230533
    Abstract: Sparse signal modulation schemes encode a data channel on a substrate in a manner that is robust, flexible to achieve perceptual quality constraints, and provides improved data capacity. The substrate is printed by any of a variety of means to apply the image, with sparse signal, to an object. After image capture of the object, a decoder processes the captured image to detect and extract data modulated into the sparse signal. The sparse signal may incorporate implicit or explicit synchronization components, which are either formed from the data signal or are complementary to it.
    Type: Application
    Filed: April 25, 2017
    Publication date: August 10, 2017
    Inventors: Vojtech Holub, Donald Haaga, Ravi K. Sharma
  • Patent number: 9710870
    Abstract: The present disclosures relates generally to digital watermarking and data hiding.
    Type: Grant
    Filed: March 3, 2015
    Date of Patent: July 18, 2017
    Assignee: Digimarc Corporation
    Inventors: Alastair M. Reed, Ravi K. Sharma
  • Publication number: 20170193628
    Abstract: Signal processing devices and methods estimate a geometric transform of an image signal. From a seed set of transform candidates, a direct least squares method applies a seed transform candidate to a reference signal and then measures correlation between the transformed reference signal and an image signal in which the reference signal is encoded. Geometric transform candidates encompass differential scale and shear, which are useful in approximating a perspective transform. For each candidate, update coordinates of reference signal features are identified in the image signal and provided as input to a least squares method to compute an update to the transform candidate. The method iterates so long as the update of the transform provides a better correlation. At the end of the process, the method identifies a geometric transform or set of top transforms based on a further analysis of correlation, as well as other results.
    Type: Application
    Filed: July 15, 2016
    Publication date: July 6, 2017
    Inventors: Ravi K. Sharma, John D. Lord, Robert G. Lyons, Osama M. Alattar, Jacob L. Boles
  • Patent number: 9665919
    Abstract: The present invention relate generally to digital watermarking and data hiding. One claim recites an apparatus comprising: electronic memory for storing first color data and second color data, the first color data and the second color data represent data from a color image signal or color video signal, and a digital watermark signal, the digital watermark signal serving to facilitate detection of a watermark message; means for separating the digital watermark signal into first frequency components and second frequency components; means for modifying the first color data by hiding the first frequency components therein; and means for modifying the second color data by hiding the second frequency components therein. Of course, other combinations and claims are provided too.
    Type: Grant
    Filed: April 18, 2016
    Date of Patent: May 30, 2017
    Assignee: Digimarc Corporation
    Inventors: Alastair M. Reed, Ravi K. Sharma
  • Publication number: 20170143249
    Abstract: Reference imagery of dermatological conditions is compiled in a crowd-sourced database (contributed by clinicians and/or the lay public), together with associated diagnosis information. A user later submits a query image to the system (e.g., captured with a smartphone). Image-based derivatives for the query image are determined (e.g., color histograms, FFT-based metrics, etc.), and are compared against similar derivatives computed from the reference imagery. This comparison identifies diseases that are not consistent with the query image, and such information is reported to the user. Depending on the size of the database, and the specificity of the data, 90% or more of candidate conditions may be effectively ruled-out, possibly sparing the user from expensive and painful biopsy procedures, and granting some peace of mind (e.g., knowledge that an emerging pattern of small lesions on a forearm is probably not caused by shingles, bedbugs, malaria or AIDS).
    Type: Application
    Filed: November 28, 2016
    Publication date: May 25, 2017
    Inventors: Bruce L. Davis, Tony F. Rodriguez, Alastair M. Reed, John Stach, Geoffrey B. Rhoads, William Y. Conwell, Shankar Thagadur Shivappa, Ravi K. Sharma, Richard F. Gibson
  • Patent number: 9652821
    Abstract: A phase deviation method determines an offset between a reference and suspect signal by analyzing a phase deviation surface created by computing a deviation metric for phase shift and then analyzing a surface formed from the deviation metrics for an array of offsets. The phase deviation method analyzes the deviation surface to determine an offset that minimizes phase deviation. This method is applied at increasing levels of detail to refine the determination of the offset.
    Type: Grant
    Filed: June 10, 2014
    Date of Patent: May 16, 2017
    Assignee: Digimarc Corporation
    Inventors: Ravi K. Sharma, John D. Lord
  • Publication number: 20170133022
    Abstract: Audio signal processing enhances audio watermark embedding and detecting processes. Audio signal processes include audio classification and adapting watermark embedding and detecting based on classification. Advances in audio watermark design include adaptive watermark signal structure data protocols, perceptual models, and insertion methods. Perceptual and robustness evaluation is integrated into audio watermark embedding to optimize audio quality relative the original signal, and to optimize robustness or data capacity. These methods are applied to audio segments in audio embedder and detector configurations to support real time operation. Feature extraction and matching are also used to adapt audio watermark embedding and detecting.
    Type: Application
    Filed: July 26, 2016
    Publication date: May 11, 2017
    Inventors: Aparna R. Gurijala, Yang Bai, Ravi K. Sharma, Brett A. Bradley