Method and System for Filtering Elongated Features
First Claim
1. A method of filtering an input image for producing an output image, said input image comprising image points comprising intensity levels to which are associated spatial coordinates, said method comprising the steps of, for a first image point located at first spatial coordinates:
- analysing intensity levels of the input image in a first vicinity of the first image point for calculating a first direction of filtering at said first image point;
computing an intensity level of a first output image point of a first output image by applying a first steerable filter kernel to the input image, which is centered at the first image point and oriented along the calculated first direction of filtering;
selecting at least a second image point in a second vicinity of said first image point in the first output image;
computing an intensity level of at least one second output image point of a second output image by applying at least a second steerable filter kernel to the input image, which is centered at the at least second image point and oriented along a second direction of filtering;
calculating a linear combination of the first output image point and of the at least second output image point for providing an output intensity level;
applying said output intensity level to an output image point of said output image, said output image point having said first spatial coordinates.
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Accused Products
Abstract
The present invention relates to a method of filtering an input image for producing an output image. The method comprising the steps of, for a first image point located at first spatial coordinates:—analysing intensity levels of the input image in a first vicinity of the first image point for calculating a first direction of filtering at said first image point;—computing an intensity level of a first output image point of a first output image by applying a first steerable filter kernel to the input image, which is centered at the first image point and oriented along the calculated first direction of filtering; selecting at least a second image point in a second vicinity of said first image point in the first output image;—computing an intensity level of at least one second output image point of a second output image by applying at least a second steerable filter kernel to the input image, which is centered at the at least second image point and oriented along a second direction of filtering;—calculating a linear combination of the first output image point and of the at least second output image point for providing an output intensity level;—applying said output intensity level to an output image point of said output image, said output image point having said first spatial coordinates.
8 Citations
14 Claims
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1. A method of filtering an input image for producing an output image, said input image comprising image points comprising intensity levels to which are associated spatial coordinates, said method comprising the steps of, for a first image point located at first spatial coordinates:
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analysing intensity levels of the input image in a first vicinity of the first image point for calculating a first direction of filtering at said first image point; computing an intensity level of a first output image point of a first output image by applying a first steerable filter kernel to the input image, which is centered at the first image point and oriented along the calculated first direction of filtering; selecting at least a second image point in a second vicinity of said first image point in the first output image; computing an intensity level of at least one second output image point of a second output image by applying at least a second steerable filter kernel to the input image, which is centered at the at least second image point and oriented along a second direction of filtering; calculating a linear combination of the first output image point and of the at least second output image point for providing an output intensity level; applying said output intensity level to an output image point of said output image, said output image point having said first spatial coordinates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14)
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13. A system for filtering an input image and producing an output image, said input image comprising image points comprising intensity levels, to which are associated spatial coordinates, said system comprising:
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means for analysing an intensity level of the input image in a first vicinity of a first image point for calculating a first direction of filtering at said first image point; means for computing an intensity level of a first output image point by applying first steerable filter kernel, which is centered at the first image point and oriented along the calculated first direction of filtering; means for selecting at least one second image point in a second vicinity of said first output image point; means for computing an intensity level of at least one second output image point by applying a second steerable filter kernel, which is centered at said second image point and oriented along a second direction of filtering; means for calculating a linear combination of the intensity levels of the first output image point and of the at least second output image point; means for applying said calculated linear combination to an intensity level of a final output image point of said output image, to which are associated said first spatial coordinates.
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Specification