Method and system for mitigation of image distortion due to optical turbulence

Abstract

A passive method and system for mitigating image distortion due to optical turbulence in a surveillance system is disclosed. An array of cameras forming a stereo camera array is employed to view a distant object or objects and background to obtain multi-hyperstereo image data, and the latter data are processed in accordance with statistical comparison and integration techniques to mitigate the effects of optical turbulence in near real-time. Further features of the invention involve comparison of multi-hyperstereo images with uncorrelated optical turbulence distortions, the reconstruction of the distant object and background using segmenting and time-integration techniques, and the execution of time-averaging and correlation algorithms.

What is claimed is: 
     
       1. A passive method of mitigating image distortion due to moderate to strong optical turbulence in a surveillance system, comprising: (a) providing an array of cameras each having a narrow field of view forming a stereo camera array, said cameras separated by at least one meter and having incorporated high power magnifying optics therein;   (b) employing the stereo camera array to view a distant object and background to obtain multiple uncoupled, optical turbulence distorted, multi-hyperstereo image data; and   (c) processing in real time said multiple uncoupled, optical turbulence distorted, multi-hyperstereo image data in accordance with statistical comparison and integration techniques to mitigate the effects of optical turbulence in near real-time.   
     
     
       2. The method of claim 1, wherein step (c) comprises comparing multi-hyperstereo images with uncorrelated optical turbulence distortions. 
     
     
       3. The method of claim 1, further comprising step (d) of reconstructing the distant object and background. 
     
     
       4. The method of claim 3, wherein step (d) comprises segmenting and time-integrating object edges and textures with correlations from subsequent multi-hyperstereo image data to reconstruct a stereo image of the distant object and background with substantial mitigation of distortions due to optical turbulence. 
     
     
       5. The method of claim 4, wherein step (d) comprises executing time-averaging and correlation algorithms. 
     
     
       6. The method of claim 1, wherein step (c) comprises short-time averaging a plurality of frames of imagery data. 
     
     
       7. The method of claim 1, wherein step (c) comprises carrying out a coarse fusion process determined by a solution of correspondence between all imagery stereo pairs. 
     
     
       8. The method of claim 1, wherein step (c) comprises comparing one of individual pixels and individual pixel areas for correspondence solution of a given stereo pair. 
     
     
       9. The method of claim 1, wherein step (c) comprises retaining and merging undistorted portions of image data derived during step (b). 
     
     
       10. The method of claim 1, wherein step (c) comprises producing undistorted images for each of a plurality of images and best stereo pair display based on a comparison of correspondence of all stereo pairs in the multi-hyperstereo image data. 
     
     
       11. A passive system for mitigating image distortion due to moderate to strong optical turbulence in a surveillance system, comprising: an array of cameras each having a narrow field of view forming a stereo camera array, said cameras separated by at least one meter and having incorporated high power magnifying optics therein;   control means for controlling the stereo camera array to view a distant object and background to obtain multiple uncoupled, optical turbulence distorted, multi-hyperstereo image data; and   real time processing means for processing said multiple uncoupled, optical turbulence distorted, multi-hyperstereo image data in accordance with statistical comparison and integration techniques to mitigate the effects of optical turbulence in near real-time.   
     
     
       12. The system of claim 11, wherein said processing means compares multi-hyperstereo images with uncorrelated optical turbulence distortions. 
     
     
       13. The system of claim 11, further comprising reconstruction means for reconstructing the distant object and background. 
     
     
       14. The system of claim 13, wherein said reconstruction means segments and time-integrates object edges and textures with correlations from subsequent multi-hyperstereo image data to reconstruct a stereo image of the distant object and background with substantial mitigation of distortions due to optical turbulence. 
     
     
       15. The system of claim 14, wherein said reconstruction means executes time-averaging and correlation algorithms. 
     
     
       16. The system of claim 11, wherein said processing means short-time averages a plurality of frames of image data. 
     
     
       17. The system of claim 11, wherein said processing means executes a coarse fusion process determined by a solution of correspondence between all imagery stereo pairs. 
     
     
       18. The system of claim 11, wherein said processing means compares one of individual pixels and individual pixel areas for correspondence solution of a given stereo pair. 
     
     
       19. The system of claim 11, wherein said processing means retains and merges undistorted portions of image data derived by said control means. 
     
     
       20. The system of claim 11, wherein said processing means produces undistorted images for each of a plurality of images and best stereo pair display based on a comparison of correspondence of all stereo pairs in the multi-hyperstereo image data.