Orthorectifying stitched oblique imagery to a nadir view, and applications thereof
First Claim
1. A method for orthorectifying oblique photographic imagery, comprising:
- (a) projecting an oblique photographic image onto three-dimensional model of terrain;
(b) sampling points of the projected photographic image from a viewport having a nadir perspective, the points being at the intersection of the three-dimensional model of terrain and parallel rays extended from the viewport;
(c) assembling the sampled points into an orthorectified image; and
(d) adjusting the orthorectified image or the sampled points approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image,wherein each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.
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Accused Products
Abstract
Embodiments of this invention relates to orthorectifying oblique imagery to a nadir view. In an embodiment, a method orthorectifies oblique photographic imagery. An oblique photographic image is projected onto a three-dimensional model of terrain. Points are sampled from the projected photographic image at the intersection of the three-dimensional model of terrain and parallel rays extended from a virtual viewport having a nadir perspective. The sampled points are assembled into an orthorectified image. Finally, the orthorectified image or the sampled points are adjusted approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image. Each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.
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Citations
23 Claims
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1. A method for orthorectifying oblique photographic imagery, comprising:
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(a) projecting an oblique photographic image onto three-dimensional model of terrain; (b) sampling points of the projected photographic image from a viewport having a nadir perspective, the points being at the intersection of the three-dimensional model of terrain and parallel rays extended from the viewport; (c) assembling the sampled points into an orthorectified image; and (d) adjusting the orthorectified image or the sampled points approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image, wherein each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for orthorectifying oblique photographic imagery, comprising:
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a projector module configured to project an oblique photographic image onto three-dimensional model of terrain; and a sampler module configured to; sample points from the projected photographic image from a viewport having a nadir perspective, the points being located at the intersection of the three-dimensional model of terrain and parallel rays extended from the viewport, and assemble the sampled points into an orthorectified image; and a foreshortening module configured to adjust the orthorectified image or the sampled points approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image, wherein each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method for orthorectifying oblique photographic imagery, comprising:
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(a) determining a point on a three-dimensional model of terrain for each point in a nadir viewport, each point being at the intersection of the three-dimensional model of terrain and parallel rays extended from the nadir viewport; (b) projecting each point determined in (a) to a position of a camera model that took an oblique photographic image to sample a point on the oblique photographic image; (c) assembling the sampled points into an orthorectified image; and (d) adjusting the orthorectified image or the sampled points approximately according to a difference in tilt angle between a camera that captured the oblique photographic image and the viewport having the nadir perspective to generate a foreshortened orthorectified image, wherein each location in the foreshortened orthorectified image corresponds linearly to a corresponding location in a two-dimensional map.
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Specification