Measuring distance using perspective
First Claim
Patent Images
1. A method, comprising:
- obtaining a measurement of a first distance from a camera to a first point in a scene;
characterizing perspective distortion in a photograph of the scene;
computing at least one other axial distance from the camera to at least one other point on a plane in the scene, based on the first distance measurement and the perspective characterization; and
wherein;
characterizing perspective distortion in the photograph further comprises;
detecting edges in the photograph, producing a first edge-detected image;
performing a first Hough transform on the first edge-detected image, producing a first Hough accumulator;
detecting edges in the first Hough accumulator, producing a second edge-detected image;
performing a second Hough transform on the second edge-detected image, producing a second Hough accumulator;
finding a brightness peak in the second Hough accumulator;
performing an inverse Hough transform on the peak, producing a first line in the first Hough accumulator, the first line representing a set of dominant lines in the photograph;
performing an inverse Hough transform on at least two points on the first line, producing at least two corresponding lines similar to the set of dominant lines in the photograph; and
finding an intersection of the corresponding lines.
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Abstract
A method is disclosed for measuring distance from a camera to parts of a scene using a characterization of perspective distortion in a photograph of the scene. In one example embodiment, a first distance measurement is obtained from the camera to a first point in the scene, the perspective distortion is characterized, and the distance to at least one other point on a plane in the scene is computed based on the first distance measurement and the perspective characterization.
8 Citations
27 Claims
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1. A method, comprising:
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obtaining a measurement of a first distance from a camera to a first point in a scene; characterizing perspective distortion in a photograph of the scene; computing at least one other axial distance from the camera to at least one other point on a plane in the scene, based on the first distance measurement and the perspective characterization; and
wherein;characterizing perspective distortion in the photograph further comprises; detecting edges in the photograph, producing a first edge-detected image; performing a first Hough transform on the first edge-detected image, producing a first Hough accumulator; detecting edges in the first Hough accumulator, producing a second edge-detected image; performing a second Hough transform on the second edge-detected image, producing a second Hough accumulator; finding a brightness peak in the second Hough accumulator; performing an inverse Hough transform on the peak, producing a first line in the first Hough accumulator, the first line representing a set of dominant lines in the photograph; performing an inverse Hough transform on at least two points on the first line, producing at least two corresponding lines similar to the set of dominant lines in the photograph; and finding an intersection of the corresponding lines. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A camera, comprising logic, the logic configured to perform the following method:
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obtaining a measurement of a first distance from a camera to a first point in a scene; characterizing perspective distortion in a photograph of the scene;
computing at least one other axial distance from the camera to at least one other point on a plane in the scene, based on the first distance measurement and the perspective characterization, and wherein;characterizing perspective distortion in the photograph further comprises; detecting edges in the photograph, producing a first edge-detected image; performing a first Hough transform on the first edge-detected image, producing a first Hough accumulator; detecting edges in the first Hough accumulator, producing a second edge-detected image; performing a second Hough transform on the second edge-detected image, producing a second Hough accumulator; finding a brightness peak in the second Hough accumulator; performing an inverse Hough transform on the peak, producing a first line in the first Hough accumulator, the first line representing a set of dominant lines in the photograph; performing an inverse Hough transform on at least two points on the first line, producing at least two corresponding lines similar to the set of dominant lines in the photograph; and finding an intersection of the corresponding lines. - View Dependent Claims (23, 24, 25)
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26. A system, comprising:
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a camera; a computer; and
wherein;the camera is configured to take a photograph of a scene; the camera is configured to measure a first distance from the camera to a first point in the scene; the photograph and the first distance measurement are transferred to the computer; the computer is configured to characterize perspective distortion in the photograph; the computer computes at least one other axial distance to at least one other point on a plane in the scene using the first distance measurement and the perspective characterization; and wherein characterizing perspective distortion in the photograph further comprises; detecting edges in the photograph, producing a first edge-detected image; performing a first Hough transform on the first edge-detected image, producing a first Hough accumulator; detecting edges in the first Hough accumulator, producing a second edge-detected image; performing a second Hough transform on the second edge-detected image, producing a second Hough accumulator; finding a brightness peak in the second Hough accumulator; performing an inverse Hough transform on the peak, producing a first line in the first Hough accumulator, the first line representing a set of dominant lines in the photograph; performing an inverse Hough transform on at least two points on the first line, producing at least two corresponding lines similar to the set of dominant lines in the photograph; and finding an intersection of the corresponding lines.
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27. A camera, comprising:
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means for obtaining a first measurement of a first distance from the camera to a first point in a scene; means for characterizing perspective distortion in a photograph of the scene; and means for computing at least one other axial distance to at least one other point on a plane in the scene using the first distance measurement and the characterization of perspective distortion, and wherein the means for characterizing perspective distortion in the photograph of the scene comprises; means for detecting edges in the photograph, producing a first edge-detected image; means for performing a first Hough transform on the first edge-detected image, producing a first Hough accumulator; means for detecting edges in the first Hough accumulator, producing a second edge-detected image; means for performing a second Hough transform on the second edge-detected image, producing a second Hough accumulator; means for finding a brightness peak in the second Hough accumulator; means for performing an inverse Hough transform on the peak, producing a first line in the first Hough accumulator, the first line representing a set of dominant lines in the photograph; means for performing an inverse Hough transform on at least two points on the first line, producing at least two corresponding lines similar to the set of dominant lines in the photograph; and means for finding an intersection of the corresponding lines.
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Specification