Apparatus and method for tracking a target
First Claim
1. A tracking system for tracking a target immersed inbackground clutter using as an input a sequence of two dimensional digitized images taken from a scene, said system comprising:
- correlation tracker means for matching a reference region image with a current digitized image and for generating a background reference point to be used for generating a first estimated track gate;
means coupled to said correlation tracker means for processing said background reference point to generate a first estimated track gate;
object tracker means for receiving said first estimated track gate from said means for processing, said object tracker means providing a second precisely defined target trackpoint and target size information; and
means for using said second target trackpoint and said target size information from said object tracker means to redefine said reference region image for use by said correlation tracker means during processing of a subsequent digitized image.
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Accused Products
Abstract
Target tracking capability is provided by a synergistic tracker system (5) which includes both a correlation tracker (30) and an object tracker (40) for processing sensor data input (10) and for generating tracking error signals (80). The operation of the synergistic tracker system is controlled by a central processing unit (70). The system operates by first correlating a reference region image with a portion of a current digitized image provided by an analog to digital converter (20). Secondly, the object tracker provides a precisely defined trackpoint for an object within the current image. The correlation tracker stabilizes and limits the portion of the digitized image that the object tracker must operate upon. Stabilizing and limiting this portion of the digitized image reduces the object tracker'"'"'s sensitivity to background clutter and sensitivity to a loss of lock induced by sensor motion. The object tracker provides a non-recursive update for the correlation'"'"'s reference region image. The correlation tracker and the object tracker are used simultaneously and cooperatively so that the strengths of one tracker are used to overcome the weaknesses of the other. A method of tracking a target immersed in background clutter is also disclosed.
93 Citations
20 Claims
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1. A tracking system for tracking a target immersed in
background clutter using as an input a sequence of two dimensional digitized images taken from a scene, said system comprising: -
correlation tracker means for matching a reference region image with a current digitized image and for generating a background reference point to be used for generating a first estimated track gate; means coupled to said correlation tracker means for processing said background reference point to generate a first estimated track gate; object tracker means for receiving said first estimated track gate from said means for processing, said object tracker means providing a second precisely defined target trackpoint and target size information; and means for using said second target trackpoint and said target size information from said object tracker means to redefine said reference region image for use by said correlation tracker means during processing of a subsequent digitized image. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A tracking system for tracking a target in a series of
two dimensional digitized images taken from a scene, said system comprising: -
correlation processor means for matching a reference region image with a current digitized image and for generating a background reference point to be used in generating a first estimated track gate; storage means connected to the correlation processor means for storing the first estimated track gate generated from the output of the correlation processor means; centroid processor means connected to the storage means for receiving the first estimated track gate, said centroid processor means generating a second precisely defined target trackpoint and target size information to be used in generating a second precisely defined track gate, said second track gate being stored in said storage means; and means for using said second target trackpoint from the centroid processor means to redefine the reference region image for use by the correlation processor means during processing of a subsequent digitized image. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method of tracking a target immersed in background clutter using as an input a sequence of two dimensional digitized images, said method comprising the steps of:
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(a) generating a background reference point for a current digitized image by using a correlation tracker to match a reference region image with said current digitized image, said background reference point to be used for generating a first estimated track gate; (b) generating a second precisely defined target trackpoint and target size information by using an object tracker to receive said first estimated track gate as an input; and (c) redefining said reference region image, for use by said correlation tracker during processing of a subsequent digitized image, by using said second precisely defined target trackpoint and said target size information from said object tracker. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification