Machine vision methods and systems for boundary feature comparison of patterns and images
AssigneeCognex Corporation
InventorsLeonid Taycher, Arman Garakani
Life of this patent
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Abstract
The invention provides boundary-based machine vision methods and systems for comparing a pattern to an image. These contemplate the steps of finding points on a boundary in the image; identifying one or more boundary features, at least one of which is made up of multiple such points; determining point-by-point relationships, if any, between each point defining the boundary feature in the image and points on a boundary in the pattern; and determining a relationship between the boundary feature in the image and the pattern (e.g., whether the boundary feature in the image matches a corresponding feature in the pattern) as a function of the point-by-point relationships.
Claims32
In a machine vision method for comparing a pattern and an image, the improvement comprising:
- A. finding points on a boundary in the image,
- B. identifying a boundary feature in the image, the boundary feature being defined by a plurality of the points on the boundary in the image,
- C. determining one or more point-to-point relationships, if any, between each point defining the boundary feature and a corresponding point, if any, on a boundary in the pattern, and
- C1. step (c) including assigning a numerical score that is a function of differences in any of location, angle or contrast of the point on the boundary feature in the image and the corresponding point, if any, on the boundary in the boundary in the pattern,
- D. determining a relationship between the boundary feature in the image and the pattern as a function of the relationship determined in step (C),
- D1. step (D) includes determining whether the boundary feature in the image is extra with respect to the pattern as a function of whether the numerical score determined in step (C1) falls below either a first threshold or a second threshold.
In a machine vision method for comparing a pattern and an image, the improvement comprising:
- A. finding points on a boundary in the image,
- B. identifying a boundary feature in the image, the boundary feature being defined by a plurality of the points on the boundary in the image,
- C. determining a quantitative point-to-point relationships, if any, between each point defining the boundary feature and a corresponding point, if any, on a boundary in the pattern, and
- C1. step (C) includes assigning a numerical score that is a function of differences in any of the location, angle or contrast of the point on the boundary feature in the image and the corresponding point, if any, on the boundary in the boundary in the pattern,
- D. determining a relationship between the boundary feature in the image and the patterns a function of the quantitative relationships determined in step (C),
- D1. step (D) includes determining whether the boundary feature in the image is extra with respect to the pattern as a function of whether the score determined in step (C1) falls below either a first threshold or a second threshold.
In a machine vision method for comparing a pattern and an image, the improvement comprising:
- A. finding points on a boundary in the image,
- B. identifying a boundary feature in the image, the boundary feature being defined by a plurality of the points on the boundary in the image,
- C. determining one or more point-to-point relationships, if any, between each point defining the boundary feature and a corresponding point, if any, on a boundary in the pattern, and
- C1. step (c) including assigning a numerical score that is a function of differences in any of location, angle or contrast of the point on the boundary feature in the image and the corresponding point, if any, on the boundary in the boundary in the pattern,
- D. determining a relationship between the boundary feature in the image and the pattern as a function of the relationship determined in step (C),
- D1. step (D) includes determining whether the boundary feature in the image is extra with respect to the pattern as a function of whether the score determined in step (C1) falls below either a first threshold or a second threshold.
In a machine vision method for comparing a pattern and an image, the improvement comprising:
- A. finding points on a boundary in the image,
- B. identifying a boundary feature in the image, the boundary feature being defined by a plurality of the points on the boundary in the image,
- C. determining a quantitative point-to-point relationships, if any, between each point defining the boundary feature and a corresponding point, if any, on a boundary in the pattern, and
- C1. step (C) includes assigning a numerical score that is a function of differences in any of the location, angle or contrast of the point on the boundary feature in the image and the corresponding point, if any, on the boundary in the boundary in the pattern,
- D. determining a relationship between the boundary feature in the image and the patterns a function of the quantitative relationships determined in step (C),
- D1. step (D) includes determining whether the boundary feature in the image is extra with respect to the pattern as a function of whether the score determined in step (C1) falls below either a first threshold or a second threshold.
Dependencies are inferred from the claim text.