US5204911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inspection method using unique templates and histogram analysis
Assignee: Individual
•
Filing: 1991-05-29
•
Granted: 1993-04-20
•
Expires: 2011-05-29
Abstract
Abstract A technique for detecting defects in stationary products or in products moving on a production line (102, FIG. 12) by analyzing their images uses a matrix or line-scan camera (104, FIG. 12) for taking images of products (102). The product's dimensions are measured with accuracy and the sizes and positions of their surface defects are determined. The technique is much faster and more accurate than current techniques and is based on an analysis of the histogram of the full image (C, FIG. 2). A carefully selected template image (A, FIG. 1) is created and saved in the memory of a computer (106, FIG. 12). The method also includes the steps of: creating and saving a histogram vector of the template image; loading look-up tables with a shifting and quantizing function for the image gray levels; saving a product image in memory to be superposed onto template image (FIG. 1); creating and saving a histogram vector of the result superposed image; analyzing the resulting histograms, i.e., finding discontinuations, changes the values of gray levels, appearance of new gray levels, etc. This results in the detection of product dimensions or surface defects and allows deciphering of product codes.
Inventors
- 👤 Nira Schwartz
- 👤 Arie Shahar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:27
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/0002; G06T7/0004; G06T7/001; G06V; G06V10/00; G06V10/70; G06V10/74; G06V10/75; G06V10/751; G06T2207/00; G06T2207/30; G06T2207/30108; G06T2207/30164
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
163 words
A method for inspecting products which may have defects or marks and move on a production line, with the use of a sensor and a processing unit with a memory, comprising: providing and saving in said memory a computer-generated artificial template image with a plurality of preselected gray levels; creating a histogram vector of said template image; creating a product image by sensing one of said products with said sensor, said product image comprising a multiplicity of pixels with intensity levels expressed as respective gray levels; modifying said product image to produce a modified product image by increasing the value of said gray levels of said product image by adding a constant value to all of said respective gray levels of said product image so as to make said gray levels of said modified product image higher than said grey levels of said template; and inspecting said product by superimposing said template image onto said modified product image, thereby creating a superposed image.
Claim 2
Independent Claim
163 words
A method for inspecting products which may have defects or marks and move on a production line, with the use of a sensor and a processing unit with a memory, comprising: providing and saving in said memory a computer-generated artificial template image with a plurality of preselected gray levels; creating a histogram vector of said template image; creating a product image by sensing one of said products with said sensor, said product image comprising a multiplicity of pixels with intensity levels expressed as respective gray levels; modifying said product image to produce a modified product image by increasing the value of said gray levels of said product image by adding a constant value to all of said respective gray levels of said product image so as to make said gray levels of said modified product image higher than said grey levels of said template; and inspecting said product by superimposing said template image onto said modified product image, thereby creating a superposed image.
Claim 3
Dependent Claim
36 words
The method of claim 1, where said superposing is produced by summing gray levels assigned to memory locations of said product image and said template image, and saving the results of the summation in said memory.
Claim 4
Dependent Claim
16 words
The method of claim 2, further including creating of a histogram vector of said superposed image.
Claim 5
Dependent Claim
25 words
The method of claim 3, further including analyzing said histogram vector of said superposed image by its discontinuities to indicate dimensions in numbers of pixels.
Claim 6
Dependent Claim
33 words
The method of claim 3, further including analyzing any new gray levels values which appeared in said histogram vector of said superposed image and were absent in said histogram of said template image.
Claim 7
Dependent Claim
27 words
The method of claim 3, further including comparing values of said histogram vector of said superposed image with that of said histogram vector of said template image.
Claim 8
Dependent Claim
21 words
The method of claim 3, further including counting the number of pixels equal to said gray level in said histogram vector.
Claim 9
Dependent Claim
29 words
The method of claim 3, further including analyzing said histogram vector of said superposed image by its discontinuities to detect, size and map said defects in numbers of pixels.
Claim 10
Dependent Claim
29 words
The method of claim 3, further including analyzing said histogram vector of said superposed image by its discontinuities to detect marks and express their size in numbers of pixels.
Claim 11
Dependent Claim
23 words
The method of claim 3, further including noting those of said products which have at least one said defect beyond a predetermined limit.
Claim 12
Dependent Claim
28 words
The method of claim 1, further include analyzing said histogram vector of said template image by its discontinuities to indicate dimensions of products expressed in numbers of pixels.
Claim 13
Dependent Claim
24 words
The method of claim 1 wherein said method is applied to detect, size, map, and decode code marks on the surface of said product.
Claim 14
Dependent Claim
16 words
The method of claim 1 wherein said method is applied to measure dimensions of said products.
Claim 15
Dependent Claim
22 words
The method of claim 1 wherein said method is applied to detect, size, map, and locate said defects on said products' surfaces.
Claim 16
Dependent Claim
25 words
The method of claim 1 wherein said method is applied to detect, size, map, and locate said defects on a threaded portion of said product.
Claim 17
Dependent Claim
26 words
The method of claim 1 wherein said method is applied to detect, size, map, and locate of said defects on a finished portion of said product.
Claim 18
Dependent Claim
26 words
The method of claim 1 wherein said method is applied to detect, size, map, and locate of said defects on a base portion of said product.
Claim 19
Dependent Claim
23 words
The method of claim 1 wherein said template image is composed of rectangular areas of different gray levels and a number of pixels.
Claim 20
Dependent Claim
32 words
The method of claim 1 wherein said template image is composed of a ring divided into plurality of sections, where each section has a different gray level represented by number of pixels.
Claim 21
Dependent Claim
30 words
The method of claim 1 wherein said template image is composed of a plurality of parallel strips, where each strip has a different gray level of any number of pixels.
Claim 22
Dependent Claim
10 words
The method of claim 1 wherein said products are bottles.
Claim 23
Dependent Claim
11 words
The method of claim 21 wherein said bottles are plastic bottles.
Claim 24
Dependent Claim
11 words
The method of claim 21 wherein said bottles are glass bottles.
Claim 25
Dependent Claim
10 words
The method of claim 1 wherein said products are transparent.
Claim 26
Dependent Claim
10 words
The method of claim 1 wherein said products are non-transparent.
Claim 27
Dependent Claim
15 words
The method of claim 1 wherein said inspecting includes measuring the height of said products.
Claim 28
Dependent Claim
15 words
The method of claim 1 wherein said inspecting includes measuring the width of said products.
Claim 29
Independent Claim
142 words
A method for inspecting products which may have defects or marks and move on a production line, with the use of a sensor and a processing unit with a memory, comprising: providing and saving in said memory a template image with a plurality of preselected gray levels; creating a histogram vector of said template image; creating a product image comprising a multiplicity of pixels with intensity levels expressed as respective gray levels; and modifying said product image to provide a modified product image by quantizing said gray levels of said product image, said quantizing being performed by converting said gray levels of said product image to a gray level which is higher than the highest one of said gray levels of said template; and inspecting said product by superimposing said template image onto said modified product image, thereby creating a superposed image.
Claim 30
Independent Claim
142 words
A method for inspecting products which may have defects or marks and move on a production line, with the use of a sensor and a processing unit with a memory, comprising: providing and saving in said memory a template image with a plurality of preselected gray levels; creating a histogram vector of said template image; creating a product image comprising a multiplicity of pixels with intensity levels expressed as respective gray levels; and modifying said product image to provide a modified product image by quantizing said gray levels of said product image, said quantizing being performed by converting said gray levels of said product image to a gray level which is higher than the highest one of said gray levels of said template; and inspecting said product by superimposing said template image onto said modified product image, thereby creating a superposed image.
Claim 31
Dependent Claim
60 words
The method of claim 28, further including mofifying said product image by repeating said quantizing in a plurality of steps and converting, in each step, said gray level of said product image to a gray level which is higher than the sum of said highest template gray level and the highest gray level obtained in a preceding said quantizing step.
References Cited (Backward Citations)
US4231014A
Cited
US4637054A
Cited
US4809342A
Cited
US4759074A
Cited
US5007096A
Cited
US4859863A
Cited
US4995091A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-04-19 | 1996-10-19 | 1997-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-19 | 2000-10-19 | 2001-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-19 | 2004-10-19 | 2005-04-20 | $7700.00 | Window Closed / Lapsed |