Positional measurement of a feature within an image
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0 Petitions
Accused Products
Abstract
The position of a feature within an image is determined by determining an initial estimate of the feature position to within a fraction of a pixel, translating the feature by an amount equal to that fraction of a pixel, determining further estimate of the translated feature position to within a fraction of a pixel and summing the pixel fraction of the previous estimate with the further estimate of the position to arrive at a refined estimate of the feature position.
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Citations
89 Claims
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1-60. -60. (canceled)
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61. A method for determining coordinates of a feature comprising:
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providing a first image including the feature, the first image comprising a plurality of pixels;
determining a first estimate of coordinates of the feature to within a fraction of a pixel;
translating the feature by a pixel translation value, wherein the sum of the pixel fraction and pixel translation value is an integer value;
determining a second estimate of coordinates of the translated feature to within a fraction of a pixel; and
summing the pixel fractions of the first estimate with the second estimate to derive a refined estimate of coordinates. - View Dependent Claims (62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 83)
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77. A method for determining coordinates of a feature comprising:
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providing at least one image including the feature, the at least one image comprising a plurality of pixels;
correlating the feature and the at least one image using a predetermined correlation function to determine coordinates of the feature to the nearest pixel;
evaluating the correlation function at a plurality of sub-pixel positions in the neighborhood of the determined coordinates to provide a plurality of values and fitting the plurality of values to a further function; and
differentiating the further function to determine its maximum, whereby coordinates corresponding to the maximum are coordinates of the feature to within a fraction of a pixel.
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78. A method for monitoring an aircraft structure comprising the steps of:
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attaching one or more image captures devices to a first portion of an aircraft structure;
attaching one or more targets to a second portion of the aircraft structure, the one or more targets being within a field of view of the one or more image capture devices;
capturing a series of images from the one or more image capture devices; and
processing the series of images to determine movement of the one or more targets. - View Dependent Claims (79, 80, 81, 82, 84)
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85. An apparatus for monitoring an aircraft structure comprising:
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at least one image capture device arranged to be attached to a first portion of the aircraft structure;
at least one target arranged to be attached to a second portion of the aircraft structure, whereby the at least one target is within the field of view of the at least one image capture device; and
an image processor arranged to receive a plurality of images from the at least one image capture device and to process the plurality of images to determine movement of the at least one target, wherein movement is selected from the group consisting of magnitude, direction, and combinations thereof. - View Dependent Claims (86, 87, 88, 89)
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Specification