Patent ID: 6970578
Filing Date: 2005-11-29
Classification: G06K

Abstract:
1. A method of generating an isolated image of manmade objects residing in an underwater environment, comprising the steps of: illuminating an image area underwater with light of a wavelength selected to generate elastic scattering of said light when incident on manmade objects and on naturally-occurring environmental features, and to generate fluorescence substantially only when incident on said naturally-occurring environmental features; sensing said elastic scattering of said light from said image area at said wavelength; forming an image of said image area using said elastic scattering of said light; sensing light indicative of said fluorescence at a plurality of fluorescence wavelengths; forming a fluorescence-based image of said image area at each of said plurality of fluorescence wavelengths wherein a plurality of fluorescence-based images are generated; forming a local standard deviation (LSD) image of said image area based on each of said image and said plurality of fluorescence-based images wherein a plurality of LSD images are generated; comparing each element of each of said plurality of LSD images to a threshold criteria to generate a corresponding plurality of first binary images, each of said plurality of first binary images defined by elements at one of a first image state and a second image state as determined by said step of comparing, wherein portions of each of said plurality of first binary images at said first image state are indicative of said manmade objects and said naturally-occurring environmental features, and wherein portions of each of said plurality of first binary images at said second image state are indicative of background in said image area that is neither said manmade objects or said naturally-occurring environmental features; logically combining said plurality of first binary images to generate a composite image mask, wherein portions of said composite image mask indicative of said background have the same binary value; generating a statistical threshold criteria for each of said plurality of fluorescence-based images using only portions thereof identified by said portions of said composite image mask; comparing each element of each of said plurality of fluorescence-based images to said statistical threshold criteria corresponding thereto to generate a corresponding plurality of second binary images, each of said plurality of second binary images defined by elements at one of a first image state and a second image state as determined by said step of comparing, wherein only portions of each of said plurality of second binary images at said first image state are indicative of said manmade objects; and logically combining at least two of said plurality of second binary images to generate a binary manmade object image mask, wherein first portions of said binary manmade object image mask indicative of said manmade objects have the same binary value while second portions of said manmade object image mask not indicative of said manmade objects have a different binary value than said first portions.