Systems and methods for detecting light sources

Abstract

A method for detecting light sources, including capturing an image including a sub-infrared light emitter, applying a filter to a pixel of the captured image to isolate a signal strength of a range of frequencies, and comparing the signal strength of the filtered pixel to an expected signal strength of a background spectra for the range of frequencies. As a result of a difference between the signal strength of the filtered pixel and the expected signal strength exceeding a predetermined threshold, the method includes identifying the pixel as corresponding to a light emitter. As a result of the difference between the signal strength of the filtered pixel and the expected signal strength not a predetermined threshold, the method includes identifying the pixel as not corresponding to a light emitter.

What is claimed is: 
     
         1 . A method comprising:
 capturing an image including a sub-infrared light emitter;   applying a filter to a pixel of the captured image to isolate a signal strength of a range of frequencies;   comparing the signal strength of the filtered pixel to an expected signal strength of a background spectra for the range of frequencies; and   as a result of a difference between the signal strength of the filtered pixel and the expected signal strength exceeding a predetermined threshold, identifying the pixel as corresponding to a light emitter; or   as a result of the difference between the signal strength of the filtered pixel and the expected signal strength not a predetermined threshold, identifying the pixel as not corresponding to a light emitter.   
     
     
         2 . The method of  claim 1 , further comprising:
 analyzing a spectral radiance of the light emitter and identifying a spectral peak of the light emitter; and   utilizing a range of frequencies corresponding to the spectral peak in applying the filter.   
     
     
         3 . The method of  claim 2 , wherein more than one spectral peak is identified, the method further comprising applying a plurality of filters to the pixel, each of the plurality of filters configured to isolate a signal strength of a range of frequencies corresponding to one of the spectral peaks. 
     
     
         4 . The method of  claim 2 , further comprising:
 analyzing a spectral radiance of the light emitter and identifying a spectral trough of the light emitter; and   applying a filter to the pixel of the captured image to isolate a signal strength of a range of frequencies corresponding to the spectral trough.   
     
     
         5 . The method of  claim 1 , further comprising:
 repeating the steps of applying, comparing, and identifying for each of a plurality of pixels of the captured image; and   generating a bitmap image wherein pixels corresponding to a light emitter are assigned a first value and pixels not corresponding to a light emitter are assigned a second value.   
     
     
         6 . The method of  claim 5 , further comprising:
 overlaying the bitmap image on the captured image; and   projecting the overlaid image as a heads-up display including indications of the light emitters.   
     
     
         7 . A system comprising:
 an image sensor configured to capture an image including a sub-infrared light emitter;   a memory configured to store the captured image;   a processor coupled to the image sensor and the memory, the processor being configured to:
 receive the captured image and apply a filter to a pixel of the captured image to isolate a signal strength of a range of frequencies; 
 compare the signal strength of the filtered pixel to an expected signal strength of a background spectra for the range of frequencies; and 
 as a result of a difference between the signal strength of the filtered pixel and the expected signal strength exceeding a predetermined threshold, identify the pixel as corresponding to a light emitter; or 
 as a result of the difference between the signal strength of the filtered pixel and the expected signal strength not a predetermined threshold, identify the pixel as not corresponding to a light emitter. 
   
     
     
         8 . The system of  claim 7 , wherein the processor is further configured to:
 analyze a spectral radiance of the light emitter and identify a spectral peak of the light emitter; and   utilize a range of frequencies corresponding to the spectral peak when the filter is applied.   
     
     
         9 . The system of  claim 8 , wherein more than one spectral peak is identified, and the processor is further configured to apply a plurality of filters to the pixel, each of the plurality of filters is configured to isolate a signal strength of a range of frequencies corresponding to one of the spectral peaks. 
     
     
         10 . The system of  claim 8 , wherein the processor is further configured to:
 analyze a spectral radiance of the light emitter and identifying a spectral trough of the light emitter; and   apply a filter to the pixel of the captured image to isolate a signal strength of a range of frequencies corresponding to the spectral trough.   
     
     
         11 . The system of  claim 7 , wherein the processor is further configured to:
 repeat the steps to apply, compare, and identify light emitters for each of a plurality of pixels of the captured image; and   generate a bitmap image wherein pixels corresponding to a light emitter are assigned a first value and pixels not corresponding to a light emitter are assigned a second value.   
     
     
         12 . The system of  claim 11 , wherein the processor is further configured to:
 overlay the bitmap image on the captured image; and   cause a heads-up display to project the overlaid image including indications of the light emitters.   
     
     
         13 . A non-transitory computer readable medium comprising instructions that, when executed by a processor, cause the processor to:
 receive a captured image including a sub-infrared light emitter;   apply a filter to a pixel of the captured image to isolate a signal strength of a range of frequencies;   compare the signal strength of the filtered pixel to an expected signal strength of a background spectra for the range of frequencies; and   as a result of a difference between the signal strength of the filtered pixel and the expected signal strength exceeding a predetermined threshold, identify the pixel as corresponding to a light emitter; or   as a result of the difference between the signal strength of the filtered pixel and the expected signal strength not a predetermined threshold, identify the pixel as not corresponding to a light emitter.   
     
     
         14 . The non-transitory computer readable medium of  claim 13 , wherein the instructions further cause the processor to:
 analyze a spectral radiance of the light emitter and identify a spectral peak of the light emitter; and   utilize a range of frequencies corresponding to the spectral peak when the filter is applied.   
     
     
         15 . The non-transitory computer readable medium of  claim 14 , wherein the instructions further cause the processor to apply a plurality of filters to the pixel, each of the plurality of filters configured to isolate a signal strength of a range of frequencies corresponding to an identified spectral peak of a spectral radiance of the light emitter. 
     
     
         16 . The non-transitory computer readable medium of  claim 14 , wherein the processor is further configured to:
 analyze a spectral radiance of the light emitter and identifying a spectral trough of the light emitter; and   apply a filter to the pixel of the captured image to isolate a signal strength of a range of frequencies corresponding to the spectral trough.   
     
     
         17 . The non-transitory computer readable medium of  claim 13 , wherein the instructions further cause the processor to:
 repeat the steps to apply, compare, and identify light emitters for each of a plurality of pixels of the captured image; and   generate a bitmap image wherein pixels corresponding to a light emitter are assigned a first value and pixels not corresponding to a light emitter are assigned a second value.   
     
     
         18 . The non-transitory computer readable medium of  claim 17 , wherein the instructions further cause the processor to:
 overlay the bitmap image on the captured image; and   cause a heads-up display to project the overlaid image including indications of the light emitters.