System and method for determining location of a device using opposing cameras

Abstract

System and method for determining location of a device using opposing cameras are disclosed. In one embodiment, the method includes activating a front-facing camera and a back-facing camera of the device, capturing a first pair of images from a first orientation using the front-facing camera and the back-facing camera, where the first pair of images includes a first front image and a first back image, monitoring the device being rotated to a second orientation, capturing a second pair of images from the second orientation using the front-facing camera and the back-facing camera, where the second pair of images includes a second front image and a second back image, and determining a location of the device using the first pair of images and the second pair of images.

We claim: 
     
         1 . A method, on a mobile device, for determining an approximate location of the mobile device, comprising:
 activating one or more cameras of said mobile device;   capturing one or more first images from a first orientation using said one or more cameras;   monitoring said mobile device being rotated to a second orientation;   capturing one or more second images from said second orientation using said one or more cameras; and   determining said approximate location of said mobile device based, at least in part, on said captured one or more first images, said captured one or more second images, said first orientation, and said second orientation.   
     
     
         2 . The method of  claim 1 , wherein activating said one or more cameras of said mobile device comprises:
 activating said one or more cameras of said mobile device with a gesture, wherein said gesture includes applying one or more user-defined movements to said mobile device.   
     
     
         3 . The method of  claim 1 , wherein said capturing of said one or more first images from said first orientation and said capturing of said one or more second images from said second orientation occurs within a predetermined period of time. 
     
     
         4 . The method of  claim 1 , and further comprising:
 determining parameters of said first orientation and said second orientation using one or more of an accelerometer, a gyroscope, or a magnetometer.   
     
     
         5 . The method of  claim 1 , wherein determining said approximate location of said mobile device comprises:
 determining a first line passing through at least one of said captured one or more first images and said mobile device;   determining a second line passing through at least one of said captured one or more second images and said mobile device; and   computing an approximate cross point based, at least in part, on said first line and said second line and an approximate rotation angle between said first line and said second line.   
     
     
         6 . The method of  claim 5 , wherein computing said approximate cross point comprises extrapolating feature points in one or more sub-regions of at least one of said captured one or more first images and extrapolating feature points in one or more sub-regions of at least one of said captured one or more second images. 
     
     
         7 . The method of  claim 5 , wherein determining said approximate location of said mobile device further comprises:
 comparing at least one first image of said captured one or more first images with images in a database of image features of a venue;   determining said first line passing through said at least one first image of said captured one or more first images and said mobile device based, at least in part, on an approximate location of said at least one first image;   comparing at least one second image of said captured one or more second images with images in said database of image features of said venue; and   determining said second line passing through said at least one second image of said captured one or more second images and said mobile device based, at least in part, on an approximate location of said at least one second image.   
     
     
         8 . The method of  claim 7 , wherein comparing said at least one first image comprises:
 selecting a first set of images from said database of image features based, at least in part, on said first orientation of said mobile device, wherein said first set of images covers a first region in view of said one or more cameras of said mobile device.   
     
     
         9 . The method of  claim 7 , wherein comparing said at least one second image comprises:
 selecting a second set of images from said database of image features based, at least in part, on said second orientation of said mobile device, wherein said second set of images covers a second region in view of said one or more cameras of said mobile device.   
     
     
         10 . The method of  claim 1 , further comprising:
 transmitting said approximate location to a positioning engine; and   determining final location of said mobile device using said approximate location at said positioning engine.   
     
     
         11 . A non-transitory storage medium, comprising computer executable code for determination of an approximate location of a mobile device, comprising:
 code for activating one or more cameras of said mobile device;   code for capturing one or more first images from a first orientation using said one or more cameras;   code for monitoring said mobile device being rotated to a second orientation;   code capturing one or more second images from said second orientation using said one or more cameras; and   code for determining said approximate location of said mobile device based, at least in part, on said captured one or more first images, said captured one or more second images, said first orientation, and said second orientation.   
     
     
         12 . The non-transitory storage medium of  claim 11 , further comprising:
 code for capturing said one or more first images from said first orientation, and for capturing said one or more second images from said second orientation, within a predetermined period of time.   
     
     
         13 . The non-transitory storage medium of  claim 11 , wherein code for determining said approximate location of said mobile device comprises:
 code for determining a first line passing through at least one of said captured one or more first images and said mobile device;   code for determining a second line passing through at least one of said captured one or more second images and said mobile device; and   code for computing an approximate cross point based, at least in part, on said first line and said second line and an approximate rotation angle between said first line and said second line.   
     
     
         14 . The non-transitory storage medium of  claim 13 , wherein code for determining said first line comprises:
 code for comparing at least one first image of said captured one or more first images with images in a database of image features of a venue;   code for determining said first line passing through said at least one first image of said captured one or more first images and said mobile device based, at least in part, on an approximate location of said at least one first image;   code for comparing at least one second image of said captured one or more second images with images in said database of image features of said venue; and   code for determining said second line passing through said at least one second image of said captured one or more second images and said mobile device based, at least in part, on an approximate location of said at least one second image.   
     
     
         15 . The non-transitory storage medium of  claim 14 , wherein code for comparing said at least one first image comprises:
 code for selecting a first set of images from said database of image features based, at least in part, on said first orientation of said mobile device, wherein said first set of images covers a first region in view of said one or more cameras of said mobile device.   
     
     
         16 . The non-transitory storage medium of  claim 15 , wherein code for comparing said at least one first image comprises:
 code for selecting a second set of images from said database of image features based, at least in part, on said second orientation of said mobile device, wherein said second set of images covers a second region in view of said one or more cameras of said mobile device.   
     
     
         17 . The non-transitory storage medium of  claim 11  further comprising:
 code for transmitting said approximate location to a positioning engine; and 
 code for determining final location of said mobile device using said approximate location at said positioning engine. 
 
     
     
         18 . A mobile device, comprising:
 a camera;   one or more processors configured to:   activate one or more cameras of said mobile device;   capture one or more first images from a first orientation using said one or more cameras;   monitor said mobile device being rotated to a second orientation;   capture one or more second images from said second orientation using said one or more cameras; and   determine an approximate location of said mobile device based, at least in part, on said captured one or more first images, said captured one or more second images, said first orientation, and said second orientation; and   a memory configured to store said approximate location of said mobile device.   
     
     
         19 . The one or more processors of  claim 18 , further configured to:
 capture said one or more first images from said first orientation, and capture said one or more second images from said second orientation, within a predetermined period of time.   
     
     
         20 . The mobile device of  claim 18 , further comprising:
 one or more of an accelerometer, a gyroscope, or a magnetometer, or combination thereof, to determine parameters of said first orientation and said second orientation.   
     
     
         21 . The one or more processors of  claim 18 , further configured to:
 determine a first line passing through at least one of said captured one or more first images and said mobile device;   determine a second line passing through at least one of said captured one or more second images and said mobile device; and   compute an approximate cross point based, at least in part, on said first line and said second line and an approximate rotation angle between said first line and said second line.   
     
     
         22 . The one or more processors of  claim 21 , further configured to:
 compare at least one first image of said captured one or more first images with images in a database of image features of a venue;   determine said first line passing through said at least one first image of said captured one or more first images and said mobile device based, at least in part, on an approximate location of said at least one first image;   compare at least one second image of said captured one or more second images with images in said database of image features of said venue; and   determine said second line passing through said at least one second image of said captured one or more second images and said mobile device based, at least in part, on an approximate location of said at least one second image.   
     
     
         23 . The one or more processors of  claim 22 , wherein comparing said at least one first image comprises:
 selecting a first set of images from said database of image features based, at least in part, on said first orientation of said mobile device, wherein said first set of images covers a first region in view of said one or more cameras of said mobile device.   
     
     
         24 . The one or more processors of  claim 23 , wherein comparing said at least one second image comprises:
 selecting a second set of images from said database of image features based, at least in part, on said second orientation of said mobile device, wherein said second set of images covers a second region in view of said one or more cameras of said mobile device.   
     
     
         25 . The one or more processors of  claim 18 , further configured to:
 transmit said approximate location to a positioning engine; and   determine final location of said mobile device using said approximate location at said positioning engine.   
     
     
         26 . A mobile device for determining an approximate location, comprising:
 one or more processors; and   a camera assist module, operating with said one or more processors, wherein said camera assist module comprises:   means for activating one or more cameras of said mobile device;   means for capturing one or more first images from a first orientation using said one or more cameras;   means for monitoring said mobile device being rotated to a second orientation;   means for capturing one or more second images from said second orientation using said one or more cameras; and   means for determining said approximate location of said mobile device based, at least in part, on said captured one or more first images, said captured one or more second images, said first orientation, and said second orientation.   
     
     
         27 . The mobile device of  claim 26 , further comprising:
 means for capturing said one or more first images and for capturing said one or more second images within a predetermined period of time.   
     
     
         28 . The mobile device of  claim 26 , further comprising:
 means for determining parameters of said first orientation and said second orientation of said one or more cameras.   
     
     
         29 . The mobile device of  claim 26 , wherein said means for determining said approximate location of said mobile device comprises:
 means for determining a first line passing through at least one of said captured one or more first images and said mobile device;   means for determining a second line passing through at least one of said captured one or more second images and said mobile device; and   means for computing an approximate cross point based, at least in part, on said first line and said second line and an approximate rotation angle between said first line and said second line.   
     
     
         30 . The mobile device of  claim 29 , wherein determining said approximate location of said mobile device further comprises:
 means for comparing at least one first image of said captured one or more first images with images in a database of image features of a venue;   means for determining said first line passing through said at least one first image of said captured one or more first images and said mobile device based, at least in part, on an approximate location of said at least one first image;   means for comparing at least one second image of said captured one or more second images with images in said database of image features of said venue; and   means for determining said second line passing through said at least one second image of said captured one or more second images and said mobile device based, at least in part, on an approximate location of said at least one second image.