Video camera-based visibility measurement system
First Claim
1. A visibility measurement system comprising an image sensing device for sensing at least a first and a second image of an environment, the visibility meansurement system comprising a digital conversion system that maps the image of the environment into a two-dimensional data array, and a processor that computes a benchmark visibility index as a summation of measurable visual characteristics that influence visibility under a benchmark environmental condition, computes a second visibility index for a second environmental condition, and computes a relative visibility value as the ratio of the second visibility index to the benchmark visibility index.
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Abstract
A visibility measurement system that computes relative visibility by comparing an images of an environment against a benchmark image. A sensing device receives an image and a digital conversion system maps the image into a two-dimensional data array. A processor converts the digital data to a value that represents visibility by identifying a region in the image that has a uniform distance from the sensing device over time, computing a benchmark visibility index for the region as a summation of measurable visual characteristics that influence visibility in the region under a benchmark environmental condition, computing a second visibility index for a second environmental condition, and computing a relative visibility value as the ration of the second visibility index in relation to the benchmark visibility index.
36 Citations
25 Claims
- 1. A visibility measurement system comprising an image sensing device for sensing at least a first and a second image of an environment, the visibility meansurement system comprising a digital conversion system that maps the image of the environment into a two-dimensional data array, and a processor that computes a benchmark visibility index as a summation of measurable visual characteristics that influence visibility under a benchmark environmental condition, computes a second visibility index for a second environmental condition, and computes a relative visibility value as the ratio of the second visibility index to the benchmark visibility index.
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6. A method for computing visibility comprising:
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sensing with a sensing device a benchmark image of an environment under a benchmark condition with a sensing device;
sensing with the sensing device a second image of an environment under a second condition;
computing a benchmark visibility index from the benchmark image as a summation of measurable visual characteristics that influence visibility;
computing a second visibility index from the second image as a summation of measurable visual characteristics that influence visibility;
computing a relative visibility value as the ratio of the second visibility index to the benchmark visibility index. - View Dependent Claims (7, 8, 9, 10, 12, 13, 14, 15)
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16. A relative visibility measurement system comprising:
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means for sensing an image of an environment;
means for identifying a region in the image that has a uniform distance from the sensing device over time;
means for computing a benchmark visibility index for the region as a summation of measurable visual characteristics that influence visibility in the region under a benchmark environmental condition;
means for computing a second visibility index for a second environmental condition;
means for computing the relative visibility in terms of the magnitude of the second visibility index in relation to the benchmark visibility index.
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17. A relative visibility measurement system comprising:
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an image sensing device for sensing an image of an environment;
a code segment for identifying a region in the image that has a uniform distance from the sensing device over time;
a code segment for computing a benchmark visibility index for the region as a summation of measurable visual characteristics that influence visibility in the region under a benchmark environmental condition;
a code segment for computing a second visibility index for a second environmental condition; and
a code segment for computing the relative visibility in terms of the magnitude of the second visibility index in relation to the benchmark visibility index.
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18. A relative visibility measurement system comprising:
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an image sensing device for sensing an image of an environment and providing a data output;
a processor for processing the data to determine relative visibility by identifying constant environmental features and comparing image contrast and luminance data relating to the environmental features against known data for the features under a benchmark condition.
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19. A relative visibility measurement system comprising:
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an image sensing device for sensing an image of an environment and providing a data output, the image sensing device placed at a first location;
a transmitting system for transmitting the data to from the first location to a second location;
a processor at the second location for processing the data to determine relative visibility by identifying constant environmental features and comparing image contrast and luminance data relating to the environmental features against known data for the features under a benchmark condition.
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20. A system for measuring relative visibility, comprising:
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a video camera that is positioned to perceive a scene including objects located at various distances from the camera, the video camera providing an output comprising an image of the scene;
a processor that computes relative visibility by approximating the distance from the camera of objects in the image and comparing a region of the image to a corresponding region in a benchmark image to determine relative visibility. - View Dependent Claims (21, 22, 23, 24, 25)
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Specification