System, a method and a computer program product for patch-based defect detection
First Claim
1. A computerized method for inspecting an article for defects based on processing of inspection images generated by collecting signals arriving from the article, the method comprising:
- obtaining a candidate pixel of the inspection image, the candidate pixel being representative of a candidate article defect location;
in a reference image, defining a source patch associated with a reference source pixel of the reference image which corresponds to the candidate pixel;
in the reference image, based on the source patch and a predefined patch-similarity criterion, determining a similarity level with respect to each of a plurality of reference patches, each of which is associated with a reference image pixel;
in the inspection image, rating each inspected pixel out of multiple inspected pixels with a representative score which is based on the similarity level of a reference patch associated with a reference pixel corresponding to the inspected pixel;
in the inspection image, selecting multiple selected inspected pixels based on the representative scores of the multiple inspected pixels;
determining a presence of a defect in the candidate pixel based on an inspected value of the candidate pixel and inspected values of the selected inspected pixels; and
in each image of a plurality of images which includes the reference image;
(a) defining multiple source patches of different shapes, wherein each of the multiple source patches is associated with a reference source pixel of the image; and
(b) for each of the source patches of the image;
based on the source patch and a respective patch-similarity criterion, determining a similarity level with respect to each of a plurality of reference patches, each of which is associated with a pixel of the image;
thereby for each of a plurality of pixels of the image, determining a plurality of similarity levels that are determined for multiple reference patches of different shapes which are associated with the respective pixel of the image;
wherein the rating comprises rating each inspected pixel out of at least one of the multiple inspected pixels with a representative score which is based on multiple similarity levels of reference patches associated with pixels of the plurality of images which correspond to the inspected pixel.
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Accused Products
Abstract
A system capable of inspecting an article for defects, the system including: a patch comparator, configured to determine with respect to each of a plurality of reference patches in a reference image a similarity level, based on a predefined patch-similarity criterion and on a source patch defined in the reference image; an evaluation module, configured to rate each inspected pixel out of multiple inspected pixels of the inspection image with a representative score which is based on the similarity level of a reference patch associated with a reference pixel corresponding to the inspected pixel; a selection module, configured to select multiple selected inspected pixels based on the representative scores of the multiple inspected pixels; and a defect detection module, configured to determine a presence of a defect in the candidate pixel based on an inspected value of the candidate pixel and inspected values of the selected inspected pixels.
55 Citations
17 Claims
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1. A computerized method for inspecting an article for defects based on processing of inspection images generated by collecting signals arriving from the article, the method comprising:
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obtaining a candidate pixel of the inspection image, the candidate pixel being representative of a candidate article defect location; in a reference image, defining a source patch associated with a reference source pixel of the reference image which corresponds to the candidate pixel; in the reference image, based on the source patch and a predefined patch-similarity criterion, determining a similarity level with respect to each of a plurality of reference patches, each of which is associated with a reference image pixel; in the inspection image, rating each inspected pixel out of multiple inspected pixels with a representative score which is based on the similarity level of a reference patch associated with a reference pixel corresponding to the inspected pixel; in the inspection image, selecting multiple selected inspected pixels based on the representative scores of the multiple inspected pixels; determining a presence of a defect in the candidate pixel based on an inspected value of the candidate pixel and inspected values of the selected inspected pixels; and in each image of a plurality of images which includes the reference image; (a) defining multiple source patches of different shapes, wherein each of the multiple source patches is associated with a reference source pixel of the image; and (b) for each of the source patches of the image;
based on the source patch and a respective patch-similarity criterion, determining a similarity level with respect to each of a plurality of reference patches, each of which is associated with a pixel of the image;thereby for each of a plurality of pixels of the image, determining a plurality of similarity levels that are determined for multiple reference patches of different shapes which are associated with the respective pixel of the image; wherein the rating comprises rating each inspected pixel out of at least one of the multiple inspected pixels with a representative score which is based on multiple similarity levels of reference patches associated with pixels of the plurality of images which correspond to the inspected pixel. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system capable of inspecting an article for defects, the system comprising:
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a memory; and a processor electronic device operatively coupled to the memory, the processor electronic device to; determine with respect to each of a plurality of reference patches in a reference image a similarity level, based on a predefined patch-similarity criterion and on a source patch which is defined in the reference image and which is associated with a reference source pixel of the reference image;
wherein the reference source pixel corresponds to a candidate pixel of an inspection image that is generated by collecting signals arriving from the article, the candidate pixel being representative of a candidate article defect location;
wherein each of the plurality of reference patches is associated with a reference image pixel;rate each inspected pixel out of multiple inspected pixels of the inspection image with a representative score which is based on the similarity level of a reference patch associated with a reference pixel corresponding to the inspected pixel; select multiple selected inspected pixels based on the representative scores of the multiple inspected pixels; and determine a presence of a defect in the candidate pixel based on an inspected value of the candidate pixel and inspected values of the selected inspected pixels, wherein in each image of a plurality of images, which includes the reference image, multiple source patches of different shapes are defined, each of the multiple source patches is associated with a reference source pixel of the image; wherein to determine the similarity level comprises the processor electronic device to determine in each image of the plurality of images, for each of the source patches of the image a similarity level with respect to each of a plurality of reference patches based on the source patch and a respective patch-similarity criterion, wherein each of the plurality of reference patches is associated with a pixel of the image; thereby for each of a plurality of pixels of the image, determining a plurality of similarity levels that are determined for multiple reference patches of different shapes which are associated with the respective pixel of the image; wherein to rate each inspected pixel comprises the processor electronic device to rate each inspected pixel out of at least one of the multiple inspected pixels with a representative score which is based on multiple similarity levels of reference patches associated with pixels of the plurality of images which correspond to the inspected pixel. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform a method for inspecting an article for defects based on processing of inspection images generated by collecting signals arriving from the article, the method comprising:
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obtaining a candidate pixel of the inspection image, the candidate pixel being representative of a candidate article defect location; in a reference image, defining a source patch associated with a reference source pixel of the reference image which corresponds to the candidate pixel; in the reference image, based on the source patch and a predefined patch-similarity criterion, determining a similarity level with respect to each of a plurality of reference patches, each of which is associated with a reference image pixel; in the inspection image, rating each inspected pixel out of multiple inspected pixels with a representative score which is based on the similarity level of a reference patch associated with a reference pixel corresponding to the inspected pixel; in the inspection image, selecting multiple selected inspected pixels based on the representative scores of the multiple inspected pixels; determining a presence of a defect in the candidate pixel based on an inspected value of the candidate pixel and inspected values of the selected inspected pixels; and in each image of a plurality of images which includes the reference image; (a) defining multiple source patches of different shapes, wherein each of the multiple source patches is associated with a reference source pixel of the image; and (b) for each of the source patches of the image;
based on the source patch and a respective patch-similarity criterion, determining a similarity level with respect to each of a plurality of reference patches, each of which is associated with a pixel of the image;thereby for each of a plurality of pixels of the image, determining a plurality of similarity levels that are determined for multiple reference patches of different shapes which are associated with the respective pixel of the image; wherein the rating includes rating each inspected pixel out of at least one of the multiple inspected pixels with a representative score which is based on multiple similarity levels of reference patches associated with pixels of the plurality of images which correspond to the inspected pixel. - View Dependent Claims (14, 15, 16, 17)
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Specification