Method and apparatus using aiming pattern for machine vision training

• US 8,302,864 B2
• Filed: 12/28/2007
• Issued: 11/06/2012
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Cognex Corporation
• Original Assignee: Cognex Corporation
• Inventors: Gerst, Carl W., Schatz, David
• Primary Examiner(s): VO, TUYEN KIM
• Application Number:
  US11/965,950
• Publication Number:
  US 20090166424A1
• Time in Patent Office: 1,775 Days
• Field of Search: 235/454, 23546201-473, 235/462.11, 235/462.14, 235/462.2, 235/462.24, 235/462.32, 235/462.45, 23547201-47203, 235/462.43
• US Class Current: 235/462.02
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned

Abstract

A method and apparatus for use with a camera that includes a field of view (FOV), the method for selecting a portion of the field of view for analysis and comprising the steps of placing at least a portion of a first object within the field of view of the camera, providing a light source separate from the camera, directing the light source toward the first object within the field of view of the camera so that the light forms an aiming pattern that is one of on and proximate a first location of interest on the first object, obtaining an image of the portion of the first object within the field of view including the aiming pattern, identifying the location of the aiming pattern in the obtained image and using the aiming pattern in the obtained image to perform a processing function.

Claims

1. A method for use with a camera that includes a field of view (FOV), the method for selecting a portion of the field of view for analysis and comprising the steps of:

(a) placing at least a portion of a first object within the field of view of the camera;

(b) providing a light source separate from the camera where the light source can be positioned separately from the camera;

(c) directing the light source toward the first object within the field of view of the camera so that the light forms an aiming pattern that is one of on and proximate a first location of interest on the first object;

(d) obtaining an image of the portion of the first object within the field of view wherein the obtained image includes the aiming pattern;

(e) identifying the location of the aiming pattern in the obtained image; and

(f) using the aiming pattern in the obtained image to perform a processing function.

2. The method of claim 1 wherein the step of performing a processing function includes performing a feature learning process on a fractional portion of the image proximate the aiming pattern to identify object features and storing learned features for subsequent object inspection.

3. The method of claim 2 wherein the aiming pattern defines an area on the object and the step of performing the feature learning process on a fractional portion includes performing the process on the portion of the image within the area defined by the aiming pattern.

4. The method of claim 2 further including the steps of placing at least a portion of a second object within the field of view of the camera, obtaining an image of the portion of the second object within the field of view and analyzing the image of the portion of the second object within the field of view to locate at least one of the learned features.

5. The method of claim 1 further including the step of storing information related to the location of the aiming pattern in the obtained image for use during analysis of subsequently obtained images of other objects.

6. The method of claim 1 wherein the obtained image is a first image, the method further including the steps of, with the aiming pattern off, obtaining a second image of the portion of the first object within the field of view and wherein the step of using the aiming pattern in the first image includes using the location of the aiming pattern in the first image to select a portion of the second image for further processing.

7. The method of claim 1 wherein the step of providing a light source includes providing a pencil beam forming light source.

8. The method of claim 1 further including the step of repeating steps (b) through (f) for at least a second location of interest.

9. The method of claim 1 further including the step of repeating steps (b) through (e) for a plurality of locations of interest, the locations of interest together defining a field of view subsection, the step of storing including storing information specifying the field of view subsection.

10. The method of claim 1 wherein the step of providing a light source includes providing a light source that can be controlled to generate any of a plurality of different aiming patterns, the method further including selecting one of the aiming patterns to be generated by the light source and, after the step of identifying the location of the aiming pattern in the obtained image, identifying the type of aiming pattern in the obtained image and identifying a specific processing function to be performed as a function of the type of aiming pattern identified.

11. The method of claim 1 wherein the step of performing a processing function includes searching a portion of the image proximate the aiming pattern for features of interest.

12. The method of claim 1 wherein the step of providing a light source separate from the camera includes providing a hand held light source.

13. A method for use with a camera having a field of view (FOV), the method for use during a commissioning procedure to identify at least a first FOV subsection, the method comprising the steps of:

(a) placing at least a portion of a first object of the first type within the field of view;

(b) directing a hand held light source toward the first object within the field of view of the camera so that the light forms an aiming pattern that is one of on and proximate a first feature of interest on the first object;

(c) obtaining an image of the portion of the first object within the field of view wherein the obtained image includes the aiming pattern;

(d) identifying the location of the aiming pattern in the obtained image; and

(e) using the location of the aiming pattern in the obtained image to perform a processing function;

wherein the light source is separate from the camera and wherein the light source can be positioned separately from the camera so that the aiming pattern can be aimed at different locations within the field of view of the camera.

14. The method of claim 13 wherein the step of using the location of the aiming pattern includes selecting a first image portion of interest which corresponds to a fraction of the obtained image proximate the aiming pattern and which also corresponds to a field of view subsection and performing a processing function on the first image portion.

15. The method of claim 14 wherein the step of performing a processing function includes examining the first image portion of interest for at least one object feature, the step of storing including, when the at least one object feature is identified, storing information associated with the at least one object feature.

16. The method of claim 13 wherein the step of directing a hand held light source includes using a pencil beam forming hand held light source.

17. A system for obtaining an image of an object within a field of view (FOV) and selecting a portion of the image for analysis, the system comprising:

a data collector for obtaining an image of a first object within a data collector field of view (FOV);

a light source that is separate from the data collector and that is separately positionable from the data collector for, when a portion of a first object is within the field of view of the data collector, directing light toward the first object within the field of view so that the light forms an aiming pattern that is one of on and proximate a first location of interest on the first object; and

a processor programmed to receive an obtained image from the data collector where the obtained image includes the aiming pattern, to identify the location of the aiming pattern in the obtained image and to use the aiming pattern in the obtained image to perform a processing function.

18. The system of claim 17 wherein the processor performs a processing function by performing a feature learning process on a fractional portion of the image proximate the aiming pattern to identify object features and storing learned features for subsequent object inspection.

19. The system of claim 17 wherein the aiming pattern defines an area on the object and the processor performs the feature learning process on a fractional portion by performing the process on the portion of the image within the area defined by the aiming pattern.

20. The system of claim 17 wherein the processor further stores information related to the location of the aiming pattern in the obtained image for use during analysis of subsequently obtained images of other objects.

21. The system of claim 17 wherein the light source is a handheld light source.

22. The system of claim 17 wherein the light source is a laser beam light source.

23. The system of claim 17 wherein the light source is controllable to generate any of a plurality of different aiming patterns, the processor programmed to, after identifying the location of the aiming pattern in the obtained image, identifying the type of aiming pattern in the obtained image and identifying a specific processing function to be performed as a function of the type of aiming pattern identified.

24. The system of claim 17 wherein the processor performs a processing function by searching a portion of the image proximate the aiming pattern for features of interest.

25. A method for use with a camera that includes a field of view (FOV), the method for selecting points within the field of view for analysis, the method comprising the step of:

(a) placing at least a portion of a first object within the field of view of the camera;

(b) directing a light source toward the first object within the field of view of the camera so that the light forms an aiming pattern on the object at a first location of interest;

(c) obtaining a first image of the portion of the first object within the field of view wherein the first image includes the aiming pattern at the first location of interest;

(d) identifying the location of the aiming pattern in the first image;

(e) with the first object still within the field of view of the camera, directing the light source toward the first object within the field of view of the camera so that the light forms an aiming pattern on the object at a second location of interest;

(f) obtaining a second image of the portion of the first object within the field of view wherein the second image includes the aiming pattern at the second location of interest;

(g) identifying the location of the aiming pattern in the second image; and

(h) using the identified locations of the aiming pattern in the first and second images to perform a processing function.

26. The method of claim 25 wherein the camera has a video mode and wherein the first and second images are obtained in rapid succession, the method further including the steps of, prior to using the identified locations of the aiming patterns to perform a processing function, directing the light source toward the first object in the field of view so that the aiming pattern is formed on the object at additional locations of interest, obtaining a plurality of additional images of the portion of the first object in the field of view with the aiming pattern at the additional locations of interest and identifying the locations of the aiming pattern in each of the obtained images, the step of using the identified locations including using at least a subset of the identified locations from all of the obtained images.

27. The method of claim 25 wherein the light source is separate from the camera and wherein the light source can be positioned separately from the camera so that the aiming pattern can be aimed at different locations within the field of view of the camera.

28. A method for use with a camera that includes a field of view (FOV), the method for selecting a function to be performed on an image obtained by the camera and comprising the steps of:

(a) forming any one of a plurality of different illumination aiming patterns on at least one surface of an object within the field of view of the camera;

(b) obtaining an image of the first object within the field of view wherein the aiming pattern appears in the obtained image;

(c) examining the obtained image to identify the aiming pattern in the obtained image;

(d) examining the aiming pattern from the obtained image to determine the type of the identified aiming pattern; and

(e) identifying a process associated with the identified type of aiming pattern wherein a different process is associated with each different type of aiming pattern.

29. The method of claim 28 further including the step of performing the identified process that is associated with the identified aiming pattern.

30. The method of claim 29 wherein a different process is associated with each of the different aiming patterns and wherein each of the processes is an inspection process.

31. The method of claim 28 further including the steps of providing a light source controllable to generate any of a plurality of different aiming patterns, selecting the one of the plurality of different aiming patterns to be generated by the light source and directing the selected aiming pattern toward the first object within the field of view of the camera so that the light forms the aiming pattern.

32. The method of claim 28 wherein the step of obtaining an image and the step of using a light source include using a light source that is separate from the imager used to obtain the image.

33. The method of claim 28 further including identifying the location of the aiming pattern in the obtained image and performing the identified process on a portion of the image associated with the location of the aiming pattern in the image.

34. A method for use with a camera that includes a field of view (FOV), the method for selecting a function to be performed on an image obtained by the camera and comprising the steps of:

(a) forming any one of a plurality of different illumination aiming patterns on at least one surface of an object within the field of view of the camera wherein the plurality of aiming patterns include at least first and second different types of aiming patterns;

(b) obtaining an image of the first object within the field of view wherein the aiming pattern appears in the obtained image;

(c) examining the obtained image to identify the aiming pattern in the obtained image;

(d) examining the aiming pattern from the obtained image to determine the type of the identified aiming pattern

(e) where the aiming pattern in the obtained image is of a first type, identifying a first process; and

(f) where the aiming pattern in the obtained image is of a second type, identifying a second process that is different than the first process.

35. The method of claim 34 further including the step of performing at least one of the identified first and second processes.

36. The method of claim 34 wherein each of the first and second processes is an inspection process.