Synchronizing multiple user devices in an immersive media environment using time-of-flight light patterns

Abstract

In one example, a device, computer-readable medium, and method for synchronizing multiple user devices in an immersive media environment using time-of-flight (ToF) light patterns are provided. In one example, a method performed by a processing system of a first device includes detecting a fiducial that is present in a light pattern projected by a second device, wherein the second device is present in a same surrounding environment as the first device, determining an identity of the second device based on an appearance of the fiducial, identifying an expected orientation of the fiducial within the light pattern, based on the identity of the second device, and determining a location of the second device relative to the first device, based on an observed orientation of the fiducial relative to the expected orientation of the fiducial.

What is claimed is: 
     
         1 . A method comprising:
 detecting, by a processing system of a first device, a fiducial that is present in a light pattern projected by a second device, wherein the second device is present in a same surrounding environment as the first device;   determining, by the processing system, an identity of the second device based on an appearance of the fiducial;   identifying, by the processing system, an expected orientation of the fiducial within the light pattern, based on the identity of the second device; and   determining, by the processing system, a location of the second device relative to the first device, based on an observed orientation of the fiducial relative to the expected orientation of the fiducial.   
     
     
         2 . The method of  claim 1 , wherein the processing system is part of a positional tracking system of the first device, and wherein the positional tracking system tracks a position of the first device in the surrounding environment based on time of flight depth estimation. 
     
     
         3 . The method of  claim 1 , wherein the appearance of the fiducial is unique to the second device. 
     
     
         4 . The method of  claim 1 , wherein the appearance of the fiducial and the expected orientation of the fiducial within the light pattern are unique to the second device. 
     
     
         5 . The method of  claim 1 , wherein the fiducial comprises a machine readable code. 
     
     
         6 . The method of  claim 5 , wherein the machine readable code encodes the identity of the second device. 
     
     
         7 . The method of  claim 6 , wherein the machine readable code further encodes at least one of: the expected orientation of the fiducial within the light pattern, a throw distance of the second device, an appearance of the light pattern, and an intensity of the light pattern. 
     
     
         8 . The method of  claim 1 , wherein the location of the second device relative to the first device is determined using an inverse homography. 
     
     
         9 . The method of  claim 1 , wherein the fiducial is one of a plurality of fiducials detected in the light pattern, and the location of the second device relative to the first device is determined using a keystone correction. 
     
     
         10 . The method of  claim 1 , further comprising:
 connecting, by the processing system, to a processing system of the second device.   
     
     
         11 . The method of  claim 10 , wherein the processing system connects to the processing system of the second device using a device identifier that is associated with the fiducial. 
     
     
         12 . The method of  claim 10 , further comprising:
 modifying, by the processing system and in response to the connecting, a light pattern projected by the first device into the surrounding environment.   
     
     
         13 . The method of  claim 12 , wherein the modifying comprises modifying the light pattern projected by the first device to reduce interference with the light pattern projected by the second device. 
     
     
         14 . The method of  claim 12 , wherein the modifying comprises combining the light pattern projected by the first device with the light pattern projected by the second device to generate a combined light pattern. 
     
     
         15 . The method of  claim 14 , wherein the combined light pattern covers a larger surface area in the surrounding environment than the light pattern projected by the first device or the light pattern projected by the second device individually. 
     
     
         16 . The method of  claim 14 , wherein the combined light pattern provides a denser pattern than the light pattern projected by the first device or the light pattern projected by the second device individually. 
     
     
         17 . The method of  claim 14 , further comprising:
 providing, by the processing system, feedback to a centralized device regarding a usage of the combined light pattern.   
     
     
         18 . A non-transitory computer-readable medium storing instructions which, when executed by a processing system of a first device including at least one processor, cause the processing system to perform operations, the operations comprising:
 detecting a fiducial that is present in a light pattern projected by a second device, wherein the second device is present in a same surrounding environment as the first device;   determining an identity of the second device based on an appearance of the fiducial;   identifying an expected orientation of the fiducial within the light pattern, based on the identity of the second device; and   determining a location of the second device relative to the first device, based on an observed orientation of the fiducial relative to the expected orientation of the fiducial.   
     
     
         19 . A first device comprising:
 a processing system including at least one processor; and   a non-transitory computer-readable medium storing instructions which, when executed by the processing system, cause the processing system to perform operations, the operations comprising:
 detecting a fiducial that is present in a light pattern projected by a second device, wherein the second device is present in a same surrounding environment as the first device; 
 determining an identity of the second device based on an appearance of the fiducial; 
 identifying an expected orientation of the fiducial within the light pattern, based on the identity of the second device; and 
 determining a location of the second device relative to the first device, based on an observed orientation of the fiducial relative to the expected orientation of the fiducial. 
   
     
     
         20 . The first device of  claim 19 , wherein the processing system is part of a positional tracking system of the first device, and wherein the positional tracking system tracks a position of the first device in the surrounding environment based on time of flight depth estimation.