Spectral filter

In a surveillance system, the improvement comprising:

• means for receiving a visible multispectral image of a field of view, said image containing desired object images and clutter images and being formed of a plurality of spectral components of different wavelengths within the spectrum range of infrared to ultraviolet;
• and image processing means for processing said image to provide an output image containing essentially only said desired objects;
• said processing means, including:
• first means for separating said image into a plurality of separate constituent spectral components and spatially dispersing said separate spectral components simultaneously over a predetermined area, with the highest wavelength spectra located at one end of said area and the lowest wavelength spectra thereof at the opposed end of said area and with the intermediate ones of said spectral components spaced therebetween;
• second means for selectively modifying individual ones of said spectral components to individually and selectively reduce the intensity of one or more of said spectral components representative of said clutter image and for outputting said spectral components, including said modified spectral components;
• third means responsive to said output of said second means for reconstituting said spectral components into a visible image of said field to produce an output image different than said input image, whereby certain of said spectral components representative of said clutter image are eliminated;

Optical Processor means for receiving a multispectral light image at an input and providing a spectrally modified image at an output, comprising:

• input means for receiving a light image;
• means coupled to said input means for dispersing said received image into a constituent plurality of spectral components and distributing said plurality of spectral components over a predetermined area;
• means located in said area responsive to said spectral components located in said space for modifying at least one of said spectral components and for reflecting said spectral components, including modified spectral components, to a common plane in essentially overlapping registered relationship to reconstitute a multispectral image;
• and output means for outputting said reconstituted image from said common plane.

In a surveillance system for monitoring objects within a field of view that presents an image containing objects distinguishable from one another by having different spectral attributes, the improvement comprising:

• first and second image processor means for processing and spectrally modifying an optical image received at an input to a spectrally different image at an output;
• said first image processor means for modifying said image along a first axis and said second image processor means for modifying said image along a second axis perpendicular to said first axis;
• and means for coupling the output of said first image processor means to the input of said second image processor means to provide an output image processed along two axes;
• and wherein each of said image processor means comprises:
• light splitter means for passing incident light traveling in a first direction and for reflecting incident light traveling from a second direction, opposite to said first direction;
• optical lens means responsive to light passed by said splitter means traveling in a first direction for condensing said light image into a stripe and responsive to a light stripe traveling in a second direction, opposed to said first direction, for enlarging said stripe into a larger light image;
• dispersing means responsive to said incident stripe of light produced by said optical lens means for dispersing said light stripe into a plurality of spectral components, each of said spectral components being in the form of a stripe and each traveling from said dispersing means at a different angle with respect thereto;
• mirror means, said mirror means having a series of individual mirror segments spaced from one another over a predetermined area;
• each of said segments having a reflectivity characteristic that is adjustable in level responsive to the level of a control input applied thereto;
• said mirror means being positioned to receive said spectral light components from said dispersing means, different ones of said spectral light components being incident upon different individual ones of said mirror segments and for attenuating and reflecting said incident spectral components back to said dispersing means;
• control means for individually controlling the reflectivity of each of said mirror segments to permit said segments to possess different reflectivity and thereby control the level of spectral components within the light reflected by said mirror means;
• said dispersing means being further responsive to said return light stripes reflected from said mirror means for reflecting said return stripes in a second direction of travel to said optical lens means, and said lens means enlarging said reflected stripes and registering such enlargements into a larger multispectral image representative of said input image, whereby the spectral components of the image formed by said reflected light may be different from and eliminate certain of the spectral components of said light stripe formed by said optical lens means.