Methods and apparatus for automatic image inspection of continuously moving objects
First Claim
1. The method of determining whether an image is substantially like a predetermined image which is subject to some minor but acceptable variations, said method comprising the steps of:
- (1) forming a template image which is representative of said predetermined image and said minor but acceptable variations by performing the steps of;
(a) identifying a plurality of training images, each of which is substantially like said image, and at least some of which includes at least some of said minor but acceptable variations from said image;
(b) representing each of a plurality of portions of each of said training images by a pixel value, each of said portions of each of said training images respectively corresponding to an associated one of said portions of said template image; and
(c) for each portion of said template image, using as the template image pixel value the largest of the pixel values for the associated portion in said training images;
(2) representing each of a plurality of portions of said template image by a pixel value;
(3) representing each of a plurality of portions of said image of a pixel value, each of said portions of said image respectively corresponding to an associated one of said portions of said template image;
(4) for each of said portions of said image, determining the difference between the pixel value of that portion of said image and the pixel value for the associated template image portion;
(5) cumulating said differences for at least some of said portions of said image to produce a cumulative difference value;
(6) comparing said cumulative difference value to a predetermined threshold value; and
(7) identifying said image as unlike said predetermined image if said cumulative differences value bears a predetermined relationship to said threshold value.
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Accused Products
Abstract
The acceptability of images is determined by comparing each image to a template image which may be an average of several images which are known to be acceptable. The amount by which the image deviates from the template image is used as a measure of the acceptability of the image. Portions of the image at or near edges in the images may be automatically excluded from this test. Another test which includes the edge portions excluded from the first test may be performed to ensure that all portions of the image are inspected. For example, this other test may include ensuring that the correct number of edge pixels are present in the image as a whole.
109 Citations
14 Claims
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1. The method of determining whether an image is substantially like a predetermined image which is subject to some minor but acceptable variations, said method comprising the steps of:
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(1) forming a template image which is representative of said predetermined image and said minor but acceptable variations by performing the steps of; (a) identifying a plurality of training images, each of which is substantially like said image, and at least some of which includes at least some of said minor but acceptable variations from said image; (b) representing each of a plurality of portions of each of said training images by a pixel value, each of said portions of each of said training images respectively corresponding to an associated one of said portions of said template image; and (c) for each portion of said template image, using as the template image pixel value the largest of the pixel values for the associated portion in said training images; (2) representing each of a plurality of portions of said template image by a pixel value; (3) representing each of a plurality of portions of said image of a pixel value, each of said portions of said image respectively corresponding to an associated one of said portions of said template image; (4) for each of said portions of said image, determining the difference between the pixel value of that portion of said image and the pixel value for the associated template image portion; (5) cumulating said differences for at least some of said portions of said image to produce a cumulative difference value; (6) comparing said cumulative difference value to a predetermined threshold value; and (7) identifying said image as unlike said predetermined image if said cumulative differences value bears a predetermined relationship to said threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. Apparatus for determining whether an image is substantially like a predetermined image which is subject to some minor but acceptable variation, said apparatus comprising:
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(1) means for forming a template image which is representative of said predetermined image and said minor but acceptable variation wherein said means for forming a template image comprises; (a) means for identifying a plurality of training images, each of which is substantially like said image, and at least some of which include at least some of said minor but acceptable variations from said image; (b) means for representing each of a plurality of portions of each of said training images by a pixel value, each of said portions of each of said training images respectively corresponding to an associated one of said portions of said template image; and (c) means for, for each portion of said template image, using as the template image pixel value the largest of the pixel values for the associated portion in said training images; (2) means for representing each of a plurality of portions of said template image by a pixel value; (3) means for representing each of a plurality of portions of said image by a pixel value, each of said portions of said image respectively corresponding to an associated one of said portions of said template image; (4) means for, for each of said portions of said image, determining the difference between the pixel value for that portion of said image and the pixel value for the associated template image portion; (5) means for cumulating said differences for at least some of said portions of said image to produce a cumulative difference value; (6) means for comparing said cumulative difference value to a predetermined threshold value; and (7) means for identifying said image as unlike said predetermined image of said cumulative difference value bears a predetermined relationship to said threshold value. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification