Product gauge methods and apparatus for use in the optical determination of the acceptability of products
First Claim
Patent Images
1. A method of determining the acceptability of a product, comprising the steps of:
- superimposing a product gauge image over an image of the product;
identifying an acceptable image by comparing the product gauge image with the image of the product;
generating a filter from a first set of acceptable images of said product;
comparing said filter with a member of a second set of images of said product to produce a processed value, said second set including at least some acceptable images;
repeating said comparing step to produce a distribution of processed values;
generating from said distribution of processed values a first range (A) of processed values, said first range comprising processed values associated with acceptable images of said product;
generating from said distribution of processed values a second range (B) of processed values, said second range comprising processed values associated with unacceptable images of said product;
comparing said filter with a further image of said product so as to produce a further processed value;
generating an indication of acceptability or unacceptability of said further image by comparing said further processed value to said first and second ranges;
if said further processed value is outside both said first and second ranges, selecting said further image only if said further image is acceptable; and
adaptively training said filter with said selected further image to produce a modified filter such that comparing said modified filter with said selected further image produces a modified processed value which is within said first range.
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Abstract
A product gauge is disclosed for use in the optical inspection of products. The product gauge can be produced from the image of a model of the product. The product gauge can also be electronically constructed on a video screen by a computer line-drawing program. The product gauge aids in the alignment and the processing of information by the optical inspecting means including aiding an operator in determining whether a product is acceptable. The product gauge can be used to quickly and accurately tailor a generalized product inspection apparatus to specific products and thus ease the change from inspecting one product to another product.
53 Citations
38 Claims
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1. A method of determining the acceptability of a product, comprising the steps of:
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superimposing a product gauge image over an image of the product; identifying an acceptable image by comparing the product gauge image with the image of the product; generating a filter from a first set of acceptable images of said product; comparing said filter with a member of a second set of images of said product to produce a processed value, said second set including at least some acceptable images; repeating said comparing step to produce a distribution of processed values; generating from said distribution of processed values a first range (A) of processed values, said first range comprising processed values associated with acceptable images of said product; generating from said distribution of processed values a second range (B) of processed values, said second range comprising processed values associated with unacceptable images of said product; comparing said filter with a further image of said product so as to produce a further processed value; generating an indication of acceptability or unacceptability of said further image by comparing said further processed value to said first and second ranges; if said further processed value is outside both said first and second ranges, selecting said further image only if said further image is acceptable; and adaptively training said filter with said selected further image to produce a modified filter such that comparing said modified filter with said selected further image produces a modified processed value which is within said first range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. The method of determining the acceptability of the appearance of each of a plurality of products comprising the steps of:
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forming an image of each of a first subplurality of said products; superimposing a product gauge image over each of the images of said first subplurality; identifying acceptable in, ages by comparing the product gauge image with each of the images of the first subplurality; combining the images of said acceptable images to produce an initial discriminant function; forming an image of each of a second subplurality of said products; using said initial discriminant function to process each of the images of said second subplurality in order to produce a processed value for each of said images from said second subplurality which is indicative of how similar said image from said second subplurality is to said initial discriminant function; selecting first processed value thresholds between which a first majority of said processed values fall; selecting second processed value thresholds between which a second majority of said processes values fall, said second majority being larger than said first majority; forming an image of each of a third subplurality of said products; using selected images of said third subplurality to progressively refine said discriminant function by (1) using said discriminant function to process each successive image from said third subplurality in order to produce a processed value for said image from said third subplurality, (2) determining whether said processed value is substantially between said second value thresholds, and (a) if not, discarding said image from said third subplurality and skipping step (3) below, or (b) if so, determining whether said processed value is substantially between first processed value thresholds, and (i) if so, continuing with step (3) below, or (ii) if not, discarding said image from said third subplurality and skipping step (3) below unless said image from said third subplurality appears acceptable, and (3) modifying said discriminant function in accordance with said image from said third subplurality; forming an image of each of a fourth subplurality of said objects; and using the refined discriminant function to determine whether or not each of the images of said fourth subplurality has an acceptable appearance. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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24. The method of determining the acceptability of the appearance of each of a plurality of products comprising the steps of:
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forming an image of each of a first subplurality of said products; combining the images of said first subplurality to produce an initial discriminant function; forming an image of each of a second subplurality of said products; using said initial discriminant function to process each of the images of said second subplurality in order to produce a processed value for each of said images from said second subplurality which is indicative of how similar said image from said second subplurality is to said initial discriminant function; selecting first processed value thresholds between which a first majority of said processed values fall; selecting second processed value thresholds between which a second majority of said processed values fall, said second majority being larger than said first majority; forming an image of each of a third subplurality of said products; using selected images of said third subplurality to progressively refine said discriminant function by (1) using said discriminant function to process each successive image from said third subplurality in order to produce a processed value for said image from said third subplurality, (2) determining whether said processed value is substantially between said second value thresholds, and (a) if not, discarding said image from said third subplurality and skipping step (3) below, or (b) if so, determining whether said processed value is substantially between first processed value thresholds, and (i) if so, continuing with step (3) below, of (ii) if not, discarding said image from said third subplurality and skipping step (3) below unless said image from said third subplurality appears acceptable, wherein the acceptability of said image of said third subplurality is determined by superimposing a product gauge in, age over said image from said third plurality and identifying the acceptability of said image by con, paring the product gauge image with said image, and (3) modifying said discriminant function in accordance with said image from said third subplurality; forming an image of each of a fourth subplurality of said products; and using the refined discriminant function to determine whether or not each of the images of said fourth subplurality has an acceptable appearance. - View Dependent Claims (25, 26, 27, 28)
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29. The method of processing a plurality of images to produce an image discriminant function comprising the steps of:
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superimposing a desired gauge image over each of a plurality of images; identifying acceptable images by comparing the superimposed desired gauge image with each of the plurality of images; subdividing a first of said acceptable images into a plurality of pixels, each of which has an initial digital value proportional to a predetermined image characteristic of the associated portion of the associated image; assigning a first numerical value to each pixel having an initial digital value which is on one side of a predetermined threshold value and assigning a second numerical value to each pixel having an initial digital value which is on the other side of said threshold value to produce an initial discriminant function; subdividing each remaining acceptable image in said plurality of images into a plurality of pixels, each of which as an initial digital value proportional to said predetermined image characteristic of the associated portion of the associated image; assigning said first numerical value to each pixel in each remaining acceptable image having an initial digital value which is on one side of said threshold value and assigning said second numerical value to each pixel in each remaining acceptable image having an initial digital value which is on the other side of said threshold value; and producing said image discriminant function by sequentially performing the logical OR operation between each of said remaining acceptable images after assigning said numerical values and the initial discriminant function, the result of each logical OR operation replacing said initial discriminant function for the next performance of said logical OR operation. - View Dependent Claims (30, 31, 32, 33)
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34. The method of determining whether or not a sample image is substantially similar to a predetermined standard image comprising the steps of:
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(a) forming a discriminant function which is representative of said standard image; (b) comparing each or a first plurality of possible examples of said sample image to said discriminant function to produce a first processed value for each of said first plurality of examples of said sample image, each of said processed values being indicative of how similar the associated example is to said standard image; (c) comparing a further possible example of said sample image to said discriminant function to produce a further processed value indicative of how similar said further example of said sample in, age is to said standard image; (d) using said first processed values to at least partly determine whether said further possible example of said sample image is substantially similar to said standard in, age, and if so, modifying said discriminant function in accordance with said further example of said sample image; (e) repeating steps (c) and (d) for each of a plurality of further possible examples of said sample image to progressively modify said discriminant function; (f) comparing said sample image to the modified discriminant function to produce a sample processed value indicative of how similar said sample image is to said standard image, and if this comparison indicates that said sample image is not substantially similar to said standard image, performing the additional steps of; (g) superimposing a standard gauge image over said sample image; and (h) comparing the superimposed standard gauge image to said sample image to determine if said sample image is substantially similar to said standard gauge image. - View Dependent Claims (35, 36, 37, 38)
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Specification