Patents by Inventor Sanbao Xu

Sanbao Xu 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: 20160261789
    Abstract: The present invention relates to a method for independently determining exposure and focus settings of a digital camera having a touch screen (15). The method comprising: detecting a first touch on the touch screen for setting a metering area (30) of a first view of the digital camera; determining an exposure setting by measuring light conditions within the metering area; detecting a second touch on the touch screen for setting a focusing area (35) of a second view of the digital camera; and determining a focus setting for an object within the focusing area.
    Type: Application
    Filed: March 6, 2015
    Publication date: September 8, 2016
    Inventor: Sanbao XU
  • Patent number: 9064323
    Abstract: The invention relates to a method for estimation of interframe motion fields operating on a stream of video frames, and more particularly for accelerating video output in multiframe super-resolution thus improving the efficiency of the multiframe integration. Relative motion field estimation is used between neighboring or close images instead of with respect to a reference image, for at least some of the frames within an integration window (TOI). The integration window is slid along the time axis each time by one (or two or a few) frames so that the current integration window preferably covers the majority of the frames in the previous integration window. Using relative motion estimation and then (tracking and) summing up the related motion fields enables, in each recursion, the absolute motion fields in a new integration window to be obtained without re-computing all the motion fields of earlier frames in the new integration window.
    Type: Grant
    Filed: July 7, 2010
    Date of Patent: June 23, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Sanbao Xu, Harald Gustafsson, Per Thorell
  • Publication number: 20150170331
    Abstract: In a first aspect, a method is provided of transforming a first image representing a view of a scenery. The method comprises obtaining the first image and obtaining a reduced first image by reducing the information density of the first image. The method further comprises obtaining an image reference for the scenery, the image reference comprising a first reference to a first reference feature at a first reference location and identifying a first image feature of the scenery at a first image location in the first reduced image. The first reference feature is matched to the first image feature, if the first reference feature matches to the first image feature, an image transformation is calculated by calculating a shift of the feature from the first reference location to the first image location. Subsequently, a transformed first image is obtained by applying the image transformation to the first image using the transform parameters estimated from the reduced images, but modified to the original scale.
    Type: Application
    Filed: March 25, 2013
    Publication date: June 18, 2015
    Inventor: Sanbao Xu
  • Publication number: 20130278719
    Abstract: Control of view synthesis of a 3D scene is described. A method comprises detecting discontinuities in a depth map that comprises depth values corresponding to a view point of a reference camera (C1). The detection comprises calculation of shifts for neighbouring pixels of the depth map, the shifts being associated with a change of viewpoint from the reference camera to a virtual camera (CV). The detected discontinuities are then analyzed, which comprises identifying increase of depths associated with the change of viewpoint from the reference camera to the virtual camera. Areas of disocclusion (108) associated with the viewpoint of the virtual camera are then identified, the areas being delimited by positions of the identified increase of depths associated with the change of viewpoint from the reference camera to the virtual camera. The identified areas of disocclusion are then provided to a view synthesis process.
    Type: Application
    Filed: November 3, 2011
    Publication date: October 24, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Thomas Rusert, Sanbao Xu
  • Patent number: 8369609
    Abstract: Image processing herein reduces the computational complexity required to estimate a disparity map of a scene from a plurality of monoscopic images. Image processing includes calculating a disparity and associated matching cost for at least one pixel block in a reference image, and then predicting, based on this disparity and associated matching cost, a disparity and associated matching cost for a pixel block that neighbors the at least one pixel block. Image processing continues with calculating a tentative disparity and associated matching cost for the neighboring pixel block, by searching for a corresponding pixel block in a different monoscopic image over a reduced range of candidate pixel blocks focused around the disparity predicted. Searching over a reduced range avoids significant computational complexity. Image processing concludes with determining the disparity for the neighboring pixel block based on comparing the matching costs associated with the tentative disparity and the disparity predicted.
    Type: Grant
    Filed: February 1, 2010
    Date of Patent: February 5, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Sanbao Xu
  • Publication number: 20120218473
    Abstract: The invention relates to a method for estimation of interframe motion fields operating on a stream of video frames, and more particularly for accelerating video output in multiframe super-resolution thus improving the efficiency of the multiframe integration. Relative motion field estimation is used between neighboring or close images instead of with respect to a reference image, for at least some of the frames within an integration window (TOI). The integration window is slid along the time axis each time by one (or two or a few) frames so that the current integration window preferably covers the majority of the frames in the previous integration window. Using relative motion estimation and then (tracking and) summing up the related motion fields enables, in each recursion, the absolute motion fields in a new integration window to be obtained without re-computing all the motion fields of earlier frames in the new integration window.
    Type: Application
    Filed: July 7, 2010
    Publication date: August 30, 2012
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Sanbao Xu, Harald Gustafsson, Per Thorell
  • Patent number: 8228367
    Abstract: A radio transceiver included in or attached to an imaging camera is used to facilitate the automatic determination of a scale factor in a three-dimensional (3D) reconstruction. The radio transceiver transmits a radio signal from each of one or more camera positions and measures a reflection profile for the transmitted signal. The measured reflection profile is compared to a simulated reflection profile, generated from a 3D model of the subject/scene of interest, to determine an estimate of an unknown scale for the 3D model. In various embodiments, the radio transceiver may be adapted from a radio device that already exists in or on the imaging camera (e.g., a cellular radio, Bluetooth® radio, or the like) or may be added to an imaging camera.
    Type: Grant
    Filed: April 9, 2009
    Date of Patent: July 24, 2012
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Björn Johansson, Beatriz Grafulla-Gonzalez, Per Persson, Sanbao Xu
  • Publication number: 20110194610
    Abstract: A method of generating a motion vector with sub-pixel resolution associated with a first portion of a first image frame in a sequence of image frames for encoding the sequence of image frames is disclosed. An error surface represents a difference between image data of the first portion of the first image frame and image data of a second portion of a second image frame, displaced with a displacement vector in relation to the first portion, and is a function of the displacement vector. The motion vector is an estimate of a displacement vector that minimizes the value of the error surface. The method includes obtaining a coarse motion vector, which is an estimate of the motion vector with integer-pixel resolution, approximating the error surface in a neighborhood of the coarse motion vector with a biquartic polynomial, and representing terms of the biquartic polynomial with orthogonal polynomials.
    Type: Application
    Filed: February 10, 2011
    Publication date: August 11, 2011
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Sanbao Xu
  • Publication number: 20110188736
    Abstract: Image processing herein reduces the computational complexity required to estimate a disparity map of a scene from a plurality of monoscopic images. Image processing includes calculating a disparity and associated matching cost for at least one pixel block in a reference image, and then predicting, based on this disparity and associated matching cost, a disparity and associated matching cost for a pixel block that neighbors the at least one pixel block. Image processing continues with calculating a tentative disparity and associated matching cost for the neighboring pixel block, by searching for a corresponding pixel block in a different monoscopic image over a reduced range of candidate pixel blocks focused around the disparity predicted. Searching over a reduced range avoids significant computational complexity. Image processing concludes with determining the disparity for the neighboring pixel block based on comparing the matching costs associated with the tentative disparity and the disparity predicted.
    Type: Application
    Filed: February 1, 2010
    Publication date: August 4, 2011
    Inventor: Sanbao Xu
  • Publication number: 20100259594
    Abstract: A radio transceiver included in or attached to an imaging camera is used to facilitate the automatic determination of a scale factor in a three-dimensional (3D) reconstruction. The radio transceiver transmits a radio signal from each of one or more camera positions and measures a reflection profile for the transmitted signal. The measured reflection profile is compared to a simulated reflection profile, generated from a 3D model of the subject/scene of interest, to determine an estimate of an unknown scale for the 3D model. In various embodiments, the radio transceiver may be adapted from a radio device that already exists in or on the imaging camera (e.g., a cellular radio, Bluetooth® radio, or the like) or may be added to an imaging camera.
    Type: Application
    Filed: April 9, 2009
    Publication date: October 14, 2010
    Inventors: Bjorn Johansson, Beatriz Grafulla-Gonzalez, Per Persson, Sanbao Xu
  • Publication number: 20100182511
    Abstract: Increasing spatial resolution of image frames in a sequence of image frames is described. Processing of a reference image frame and a current image frame is performed that involves updating a resulting image frame with data resulting from the processing. Calculation (203) of an upsampled current frame is performed by upsampling the current frame with an upsampling factor and interpolating the pixel data of the current frame. Calculation (205) of a plurality of motion vectors is performed via two-dimensional block motion estimation between the upsampled current frame and the reference frame resulting in a respective motion vector for each block. A motion mode in terms of whether the motion of the upsampled current frame is any of a global translation, a rotation and a complex motion is decided, involving analyzing the calculated motion vectors.
    Type: Application
    Filed: January 14, 2010
    Publication date: July 22, 2010
    Inventor: Sanbao Xu