Fusion night vision system

Abstract

A fusion night vision system having image intensification and thermal imaging capabilities includes an edge detection filter circuit to aid in acquiring and identifying targets. An outline of the thermal image is generated and combined with the image intensification image without obscuration of the image intensification image. The fusion night vision system may also include a parallax compensation circuit to overcome parallax problems as a result of the image intensification channel being spaced from the thermal channel. The fusion night vision system may also include a control circuit configured to maintain a perceived brightness through an eyepiece over a mix of image intensification information and thermal information. The fusion night vision system may incorporate a targeting mode that allows an operator to acquire a target without having the scene saturated by a laser pointer. The night vision system may also include a detector, an image combiner for forming a fused image from the detector and a display, and a camera aligned with image combiner for recording scene information processed by the first detector.

1 . A fusion night vision system, comprising:
 a housing;   a first channel at least partially disposed within the housing for processing information in a first range of wavelengths;   a second channel at least partially disposed within the housing for processing information in a second range of wavelengths;   an edge detection filter circuit coupled to the second channel;   a display for projecting an output from the edge detection filter circuit; and   an optical image combiner aligned with the display for combining information from the first channel with the output of the edge detection filter circuit.   
     
     
         2 . The fusion night vision system of  claim 1 , wherein the first channel has an objective focus and an image intensification tube optically aligned with the optical image combiner and an eyepiece to enable direct viewing of a scene by an operator and the second channel has an objective focus and a focal plane array. 
     
     
         3 . The fusion night vision system of  claim 1 , further comprising an eyepiece optically aligned with the optical image combiner to enable an operator to view a fused image from the first channel and the second channel. 
     
     
         4 . The fusion night vision system of  claim 3 , wherein the edge detection filter circuit calculates a value for a target pixel based on received values of surrounding pixels and the calculated value is displayed in the display for viewing by the operator. 
     
     
         5 . The fusion night vision system of  claim 1 , wherein the first range of wavelengths is approximately 400 nm to approximately 900 nm and the second range of wavelengths is approximately 7,000 nm to approximately 14,000 nm. 
     
     
         6 . The fusion night vision system of  claim 4 , wherein the calculated value is the sum of the product of a first multiplier and the target pixel value, the product of a second multiplier and the immediately surrounding received pixel values, and the product of a third multiplier and the next surrounding received pixel values. 
     
     
         7 . The fusion night vision system of  claim 4 , wherein the edge detection filter circuit multiples a received target pixel value by a first multiplier, multiples a plurality of immediately surrounding received pixel value by a second multiplier, and multiples a plurality of next surrounding received pixel value by a third multiplier to obtain the calculated value. 
     
     
         8 . The fusion night vision system of  claim 1 , wherein the edge detection filter circuit comprises a multi-row, multi-column buffer and a multi-row, multi-column convolution kernel. 
     
     
         9 . A fusion night vision system, comprising:
 a housing;   a first channel at least partially disposed within the housing for processing information in a first range of wavelengths;   a second channel at least partially disposed within the housing for processing information in a second range of wavelengths;   an edge detection filter circuit coupled to the second channel;   a display for projecting an output from the edge detection filter circuit; and   an optical image combiner aligned with the display for combining information from the first channel with the output of the edge detection filter circuit.   
     
     
         10 . The fusion night vision system of  claim 9 , wherein the first channel has an objective focus and an image intensification tube optically aligned with the optical image combiner and an eyepiece to enable direct viewing of a scene by an operator and the second channel has an objective focus and a focal plane array. 
     
     
         11 . The fusion night vision system of  claim 9 , further comprising an eyepiece optically aligned with the optical image combiner to enable an operator to view a fused image from the first channel and the second channel. 
     
     
         12 . The fusion night vision system of  claim 11 , wherein the edge detection filter circuit calculates a value for a target pixel based on received values of surrounding pixels and the calculated value is displayed in the display for viewing by the operator. 
     
     
         13 . The fusion night vision system of  claim 9 , wherein the first range of wavelengths is approximately 400 nm to approximately 900 nm and the second range of wavelengths is approximately 7,000 nm to approximately 14,000 nm. 
     
     
         14 . The fusion night vision system of  claim 12 , wherein the calculated value is the sum of the product of a first multiplier and the target pixel value, the product of a second multiplier and the immediately surrounding received pixel values, and the product of a third multiplier and the next surrounding received pixel values. 
     
     
         15 . The fusion night vision system of  claim 12 , wherein the edge detection filter circuit multiples a received target pixel value by a first multiplier, multiples a plurality of immediately surrounding received pixel value by a second multiplier, and multiples a plurality of next surrounding received pixel value by a third multiplier to obtain the calculated value. 
     
     
         16 . The fusion night vision system of  claim 9 , wherein the edge detection filter circuit comprises a multi-row, multi-column buffer and a multi-row, multi-column convolution kernel. 
     
     
         17 . The fusion night vision system of  claim 10 , wherein the optical image combiner is a beam splitter and is aligned between an exit of the image intensifier tube and an eyepiece to enable an operator to view a fused image. 
     
     
         18 . A method of optically combining scene information in a fusion night vision system, comprising the steps of:
 acquiring information representative of a scene from a first channel, the first channel configured to process information in a first range of wavelengths;   acquiring information representative of the scene from a second channel, the second channel configured to process information in a second range of wavelengths;   filtering the acquired scene information from the second channel in a filter to locate pixel intensity discontinuities; and   combining the scene information from the first channel with an output from the filter in an optical image combiner for viewing by an operator.