Generalized biased centroid edge locator
First Claim
1. In a tracking system for locating a leading edge of an object within a video frame of data, the video frame having pixels arranged generally vertically and horizontally, and the object is defined within the video frame in accordance with the intensity of the pixels,a processor for examining the intensity of the pixels and for determining the leading edge of the object within the video frame, the processor comprising:
- (a) means for defining a gate having a position within the video frame,(b) means for determining a centroid of a portion of the object within the gate, the centroid having a position defined by a line having a slope,(c) means for testing if the centroid falls within a preselected section of the gate, and moving an edge of the gate to define a new gate if the centroid does not fall within the preselected section of the gate, and redetermining the centroid for the portion of the object appearing within the new gate, and(d) means for determining the leading edge of the object in accordance with the position of the gate, the position of the centroid, and the slope,wherein said processor outputs the position of the leading edge of the object for use in tracking and intercepting the object.
2 Assignments
0 Petitions
Accused Products
Abstract
An edge locator processor having memory and which employs a generalized biased centroid edge locator process to determining the leading edge of an object in a scene moving in a generally horizontal direction across a video screen. The generalized biased centroid edge locator process includes defining a gate and determining the centroid position for that portion of the object within the gate. This occurs for a succession of gates, until predetermined conditions are met. By constructing this series of successively expanding gates, a left gate edge position and centroid position may be determined for each gate to define a series of left edge and centroid positions. These values may be linearly correlated to provide a slope and an intercept, from which the edge may be determined.
-
Citations
17 Claims
-
1. In a tracking system for locating a leading edge of an object within a video frame of data, the video frame having pixels arranged generally vertically and horizontally, and the object is defined within the video frame in accordance with the intensity of the pixels,
a processor for examining the intensity of the pixels and for determining the leading edge of the object within the video frame, the processor comprising: -
(a) means for defining a gate having a position within the video frame, (b) means for determining a centroid of a portion of the object within the gate, the centroid having a position defined by a line having a slope, (c) means for testing if the centroid falls within a preselected section of the gate, and moving an edge of the gate to define a new gate if the centroid does not fall within the preselected section of the gate, and redetermining the centroid for the portion of the object appearing within the new gate, and (d) means for determining the leading edge of the object in accordance with the position of the gate, the position of the centroid, and the slope, wherein said processor outputs the position of the leading edge of the object for use in tracking and intercepting the object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for locating a leading edge of an object within a video frame of data, the video frame having pixels arranged generally vertically and horizontally, and the object is defined within the video frame in accordance with the intensity of the pixels, the method comprising the steps of:
-
defining a gate having a predetermined width and position within the video frame, determining a centroid of the object within the gate, the centroid having a position defined by a line having a slope; testing if the centroid falls within a preselected section of the gate, and moving an edge of the gate to define a new gate if the centroid does not fall within the preselected section of the gate and redetermining the centroid for the portion of the object appearing within the new gate, where the determining and testing steps are repeated until the centroid falls within the preselected section of the gate; and determining the leading edge of the object in accordance with the position of the gate, the position of the centroid, and the slope. - View Dependent Claims (12, 13, 14, 15, 16)
-
-
17. An airborne object tracking and defeat system comprising:
-
a sensor for capturing an image of the object; a track processor for receiving the image captured by the sensor and for locating a leading edge of the object appearing in the image within a single video frame of data, where the video frame has pixels arranged generally vertically and horizontally, and where the object is defined within the video frame in accordance with the intensity of the pixels; an edge detector within the track processor for examining the intensity of the pixels from the memory and for determining the leading edge of the object within the video frame, the edge detector performing the steps of; (a) defining a gate having a position within the video frame, (b) calculating partial sums and a normalization value in accordance with the intensity of the pixels and in accordance with the position of the pixels, (c) determining a centroid of a portion of the object within the gate in accordance with the partial sums and the normalization value, the centroid having a position defined by a line having a slope, (d) testing if the centroid falls within a preselected section of the gate, and moving an edge of the gate to define a new gate if the centroid does not fall within the preselected section of the gate, and redetermining the centroid for the portion of the object appearing within the new gate, and (e) determining the leading edge of the object in accordance with the position of the gate, the position of the centroid, and the slope; an aim controller receiving the position of the leading edge of the object from the track processor and generating output commands based on the position of the leading edge of the object; and a positional gimble receiving the output commands and translating in response thereto.
-
Specification