Patents by Inventor Marc P. Christensen

Marc P. Christensen 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: 10768339
    Abstract: The present disclosure describes an imaging system, method, and apparatus for identifying a latent image of a hidden object. A light source generates a first beam of narrow-band light and a second beam of narrow-band light that has temporal fluctuations correlated with the first beam. A frequency modulator shifts a temporal frequency of at least one of the first beam or the second beam. The first beam is directed towards a first scattering surface and the second beam is directed towards a second scattering surface. The first scattering surface scatters the first beam to a scattered light that illuminates a hidden object. The hidden object reflects at least a portion of the scattered light towards the second scattering surface, the reflected light interferes with the second beam and produces an interference pattern on the second scattering surface.
    Type: Grant
    Filed: July 25, 2017
    Date of Patent: September 8, 2020
    Assignee: Southern Methodist University
    Inventors: Marc P. Christensen, Prasanna Rangarajan
  • Patent number: 10638030
    Abstract: The present disclosure includes a method for operating a camera. A lens or a sensor of the camera is rotated about an axis to a plurality of positions, and the rotation generates a rotation of a plane of sharp focus of the camera. At each of the plurality of positions, an image is captured. For each image, a substantially in-focus region is determined. The substantially in-focus regions are combined to generate a composite image.
    Type: Grant
    Filed: January 30, 2018
    Date of Patent: April 28, 2020
    Assignee: Southern Methodist University
    Inventors: Indranil Sinharoy, Marc P. Christensen, Prasanna Rangarajan
  • Patent number: 10516874
    Abstract: A system includes a camera and a projector for capturing spatial detail having resolution exceeding that afforded by the imaging optics, and recovering topographic information lost to the projective nature of imaging. The projector projects a spatial pattern onto the scene to be captured. The spatial patterns may include any pattern or combination of patterns that result in complex sinusoidal modulation. Spatial detail such as texture on the objects in the scene modulate the amplitude of the spatial pattern, and produce Moiré fringes that shifts previously unresolved spatial frequencies into the camera's optical passband. The images may be demodulated, and the demodulated components may be combined with the un-modulated components. The resulting image has spatial detail previously inaccessible to the camera owing to the band-limited nature of the camera optics. A spatial pattern may also be projected and received by the camera to estimate topographic information about the scene.
    Type: Grant
    Filed: September 4, 2015
    Date of Patent: December 24, 2019
    Assignee: Southern Methodist University
    Inventors: Prasanna Rangarajan, Vikrant R. Bhakta, Marc P. Christensen, Panos Papamichalis
  • Patent number: 10453211
    Abstract: The present disclosure discloses an imaging system, method, and apparatus for identifying information of a hidden object. A light source generates a first beam of narrow-band light and a second beam of narrow-band light that has temporal fluctuations correlated with the first beam. The first beam is directed towards a first scattering surface and the second beam is directed towards a second scattering surface. The first scattering surface scatters the first beam to a scattered light that illuminates a hidden object, the hidden object reflects at least a portion of the scattered light towards the second scattering surface, the reflected light interferes with the second beam and produces an interference pattern on the second scattering surface. An image sensor detects irradiance of the interference pattern on the second scattering surface.
    Type: Grant
    Filed: July 25, 2017
    Date of Patent: October 22, 2019
    Assignee: Southern Methodist University
    Inventors: Marc P. Christensen, Prasanna Rangarajan
  • Publication number: 20160080726
    Abstract: A system includes a camera and a projector for capturing spatial detail having resolution exceeding that afforded by the imaging optics, and recovering topographic information lost to the projective nature of imaging. The projector projects a spatial pattern onto the scene to be captured. The spatial patterns may include any pattern or combination of patterns that result in complex sinusoidal modulation. Spatial detail such as texture on the objects in the scene modulate the amplitude of the spatial pattern, and produce Moiré fringes that shifts previously unresolved spatial frequencies into the camera's optical passband. The images may be demodulated, and the demodulated components may be combined with the un-modulated components. The resulting image has spatial detail previously inaccessible to the camera owing to the band-limited nature of the camera optics. A spatial pattern may also be projected and received by the camera to estimate topographic information about the scene.
    Type: Application
    Filed: September 4, 2015
    Publication date: March 17, 2016
    Applicant: SOUTHERN METHODIST UNIVERSITY
    Inventors: Prasanna Rangarajan, Vikrant R. Bhakta, Marc P. Christensen, Panos Papamichalis
  • Patent number: 9131223
    Abstract: A system includes a camera and a projector for capturing spatial detail having resolution exceeding that afforded by the imaging optics, and recovering topographic information lost to the projective nature of imaging. The projector projects a spatial pattern onto the scene to be captured. The spatial patterns may include any pattern or combination of patterns that result in complex sinusoidal modulation. Spatial detail such as texture on the objects in the scene modulate the amplitude of the spatial pattern, and produce Moiré fringes that shifts previously unresolved spatial frequencies into the camera's optical passband. The images may be demodulated, and the demodulated components may be combined with the un-modulated components. The resulting image has spatial detail previously inaccessible to the camera owing to the band-limited nature of the camera optics. A spatial pattern may also be projected and received by the camera to estimate topographic information about the scene.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: September 8, 2015
    Assignee: Southern Methodist University
    Inventors: Prasanna Rangarajan, Vikrant R. Bhakta, Marc P. Christensen, Panos Papamichalis
  • Patent number: 9030594
    Abstract: Systems and methods can be configured to perform operations related to digital image processing. In a general aspect, this disclosure describes systems and methods relating to processing digital images for imaging system characterization and image quality enhancement. In some implementations, a method for digital image processing includes measuring a first phase transfer function (PTF) of a first digital image and a second PTF of a second digital image. The second digital image captures a spatially shifted version of the first digital image. The first PTF and the second PTF are compared and a spatial shift of the second image to the first image is determined.
    Type: Grant
    Filed: April 19, 2012
    Date of Patent: May 12, 2015
    Assignee: Southern Methodist University
    Inventors: Vikrant R. Bhakta, Manjunath Somayaji, Marc P. Christensen
  • Patent number: 8823822
    Abstract: Systems and methods can be configured to perform operations related to determining a phase transfer function of a digital imaging system. A digital image that includes at least one edge is received, the at least one edge includes a plurality of pixels with disparate pixel values. The at least one edge from the digital image is identified and an edge spread function is generated based on the identified edge. The edge spread function can be generated by taking at least one slice across the identified at least one edge. A line spread function is generated based on the edge spread function. An optical transfer function is generated based on a Fourier transform of the line spread function. A phase error is also identified. The phase transfer function of the digital image is identified based on the phase of the generated optical transfer function and the identified phase error.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: September 2, 2014
    Assignee: Southern Methodist University
    Inventors: Vikrant R. Bhakta, Marc P. Christensen
  • Patent number: 8665361
    Abstract: A system for capturing super-resolved images includes a camera and a projector. The projector projects a spatially periodic illumination pattern onto the scene to be captured. The spatially periodic illumination patterns may include any pattern or combination of patterns that result in complex modulation. The objects of the scene modulate the spatially periodic illumination patterns, shifting high spatial frequencies into the passband of the camera's optical transfer function. The images may be demodulated, and the demodulated components may be combined with un-modulated components. The resulting image has characteristics of the high spatial frequencies previously beyond the optical passband of the camera.
    Type: Grant
    Filed: May 21, 2010
    Date of Patent: March 4, 2014
    Assignee: Southern Methodist University
    Inventors: Prasanna Rangarajan, Vikrant R. Bhakta, Marc P. Christensen
  • Patent number: 6326600
    Abstract: An optical interconnection for connecting a first integrated circuit to a second integrated circuit includes a plurality of light sources, a plurality of light detectors, a symmetric imaging system, and a plurality of beam steering elements, one for each of the plurality of light sources. Each of the beam steering elements is configured to steer light from its corresponding light source to a new angle which causes the symmetric imaging system to have an effective aperture closer to its plane of symmetry. A mirror may be inserted in the plane of symmetry of the imaging system that folds the system back upon itself, making the object plane and image plane co-incident.
    Type: Grant
    Filed: June 21, 1999
    Date of Patent: December 4, 2001
    Assignee: Applied Photonics, Inc.
    Inventors: Marc P. Christensen, Predrag Milojkovic, Michael W. Haney
  • Patent number: 5467211
    Abstract: A sliding banyan switching network is disclosed for signal switching in an electrical or an optical network. The sliding banyan network routes up to N signals through a plurality of stages, each containing a plurality of switches. The sliding banyan network determines when a signal reaches its destination address by keeping track of the number of successful consecutive routings through the stages of the network. When this number reaches a predetermined number, the signal has reached its destination. The nodes of each stage are formed on a single substrate and the interconnections are implemented by optical connections. Only a single input line and a single output line for each set of nodes connects the sliding banyan network to the external system.
    Type: Grant
    Filed: January 25, 1995
    Date of Patent: November 14, 1995
    Assignee: Capital Photonics, Inc.
    Inventors: Michael W. Haney, Marc P. Christensen