Methods and apparatus for optically determining the acceptability of products
First Claim
1. The method of determining the acceptability of the appearance of each of a plurality of objects comprising the steps of:
- forming an image of each of a first subplurality of said objects;
combining the images of said first subplurality to produce an initial discriminant function;
forming an image of each of a second subplurality of said objects;
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 objects;
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.
1 Assignment
0 Petitions
Accused Products
Abstract
The acceptability of the appearance of objects such as consumer products is determined by forming an initial discriminant function as a composite of a relatively small number of images which are known to be acceptable. This initial discriminant function is then used to gather statistical information about how a first relatively large number of images compares to the initial discriminant function. Thereafter, this statistical information is used to select or aid in the selection of acceptable images from a second relatively large number of images, and the images selected as acceptable are used to refine the discriminant function. The refined discriminant function is then used (e.g., during actual product inspection) to determine which objects have an acceptable appearance and which do not.
-
Citations
44 Claims
-
1. The method of determining the acceptability of the appearance of each of a plurality of objects comprising the steps of:
-
forming an image of each of a first subplurality of said objects; combining the images of said first subplurality to produce an initial discriminant function; forming an image of each of a second subplurality of said objects; 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 objects; 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 (2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 41)
-
-
10. The method of processing a plurality of images to produce an image discriminant function comprising the steps of:
-
subdividing a first of said 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 image in said plurality of images into a plurality of pixels, each of which has 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 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 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 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 (11, 42)
-
-
14. Apparatus for determining the acceptability of the appearance of each of a plurality of objects comprising:
-
means for forming an image of each of a first subplurality of said objects; means for combining the images of said first subplurality to produce an initial discriminant function; means for forming an image of each of a second subplurality of said objects; means for 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; means for selecting first processed value thresholds between which a first majority of said processed values fall; means for selecting second processed value thresholds between which a second majority of said processed values fall, said second majority being larger than said first majority; means for forming an image of each of a third subplurality of objects; means for using selected images of said third subplurality to progressively refine said discriminant function by (1) using the 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 processed value thresholds, and (a) if not, discarding said image from said third subplurality and skipping (3) below, or (b) if so, determining whether said processed value is substantially between said first processed value thresholds, and (i) if so, continuing with (3) below, or (ii) if not, discarding said image from said third subplurality and skipping (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; means for forming an image of each of a fourth subplurality of said objects; and means for 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 (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 43, 44)
-
-
27. Apparatus for processing a plurality of images to produce an image discriminant function comprising:
-
means for subdividing a first of said 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; means for 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; means for subdividing each remaining image in said plurality of images into a plurality of pixels, each of which has an initial digital value proportional to said image characteristic of the associated portion of the associated image; means for assigning said first numerical value to each pixel in each remaining image having an initial digital value which is on one side of said threshold value which is on one side of said threshold value and assigning said second numerical value to each pixel in each remaining image having an initial digital value which is on the other side of said threshold value; and means for producing said image discriminant function by sequentially performing the logical OR operation between each of said remaining 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 (28)
-
-
29. A method of determining the acceptability of a product, comprising the steps of:
-
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 (30, 31, 32, 33)
-
-
34. Apparatus for determining the acceptability of a product, comprising:
-
means for generating a filter from a first set of acceptable images of said product; means for 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; means for repeating said comparing function to produce a distribution of processed values; means for 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; means for 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; means for comparing said filter with a further image of said product so as to produce a further processed value; means for 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 first and second ranges, means for selecting said further image only if said further image is acceptable; and means for 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 (35, 36, 37, 38)
-
-
39. The method of determining whether or not a sample image is substantially similar to a predetermined standard image comprising the steps of:
-
(a) forming a discriminant function which is representative of said standard image; (b) comparing each of 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 image 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 image, 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; and (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.
-
-
40. Apparatus for determining whether or not a sample image is substantially similar to a predetermined standard image comprising:
-
means for forming a discriminant function which is representative of said standard image; means for comparing each of 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; means for 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 image is to said standard image; means for 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 image, and of so, modifying said discriminant function in accordance with said further example of said sample image; means for repeating the two preceding functions for each of a plurality of further possible examples of said sample image to progressively modify said discriminant function; and means for 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.
-
Specification