Method and apparatus for inspecting objects using multiple images having varying optical properties

• US 8,073,234 B2
• Filed: 08/27/2007
• Issued: 12/06/2011
• Est. Priority Date: 08/27/2007
• Status: Active Grant

• Current Assignee: Acushnet Company (FILA Holdings Corp.)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Harris, Kevin M., Furze, Paul A.
• Primary Examiner(s): Mariam, Daniel
• Assistant Examiner(s): RICE, ELISA M
• Application Number:
  US11/845,177
• Publication Number:
  US 20090060315A1
• Time in Patent Office: 1,562 Days
• Field of Search: None
• US Class Current: 382/141
• CPC Class Codes: G01N 21/951 Balls
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 2207/10144 Varying exposure
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 2207/30224 Ball; Puck
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 2201/06 Recognition of objects for industrial automation

Abstract

An automated object inspection system is presented. The inspection system includes an imaging system to produce at least two images of said object having different optical properties and an analyzer coupled to the imaging system to receive the images and to perform a variety of inspection operations on said images. The imaging system may produce images of the object under inspection in the visible range having varying exposure values. A vision engine included in the analyzer may combine said images through an algorithmic process into one image having high light dynamic range. Alternatively, the imaging system may produce images of the object in the visible or non-visible electromagnetic range. The analyzer may perform inspection routines on said images. An imaging system capable of producing digital video is presented, wherein each frame of video produced by said camera is composed of multiple images having different optical properties.

Claims

1. A method for automatically inspecting a golf ball, said method comprising the steps of:

(i) producing at least two images of said first golf ball having different optical properties using an imaging system having at least two image sensors, wherein said image sensors produce at least two separate images in the same spectral range of the electromagnetic spectrum from the same perspective using a common light source to provide incident light for each image, said images being produced at different times in succession and wherein each image is of different brightness so that each image shows the same surface of the golf ball, each image having a different light exposure time so that different levels of incident light are captured and each image shows different visible areas and shadowed areas of the surface;

combining said images from step (i) into one image, the single combined image showing the same surface of the golf ball as shown in the separate images, the different areas of the surface being equally visible on the combined image; and

(iii) comparing the combined image to master images of an exemplary golf ball using an analyzer coupled to said imaging system via an electronic link so that defects on the surface of the first golf ball are detected.

2. The method of claim 1, wherein said analyzer employs an algorithmic image combining process to blend the tonal and luminance attributes of said images.

3. The method of claim 1, wherein said analyzer further comprises:

(i) a vision engine to perform analytical operations on said images;

(ii) a monitor to display images processed at said vision engine; and

(iii) a keyboard.

4. The automated inspection system method of claim 3, wherein said image sensors are photosensitive pixel array image sensors arranged to collect at least two images of said golf ball in the visible electromagnetic range.

5. The method of claim 4, wherein each image sensor

(i) is a charged-coupled device (CCD),

(ii) is a complementary metal-oxide-semiconductor (CMOS) sensor,

(iii) has a high electrical dynamic range,

(iv) has a bit depth of 10 bits per pixel, or

(v) has a bit depth of 12 bits per pixel.

6. The method of claim 5, wherein said images have varying light exposure values.

7. The method of claim 6, wherein said vision engine combines said images through an algorithmic process to produce one image with a high light dynamic range.

8. The of claim 7, wherein the image produced by the vision engine has a light dynamic range of 1000:

1 to 2000;

1.

9. The method of claim 7, wherein the image produced by the vision engine has a light dynamic range of 2000:

1 to 4000;

1.

10. The method of claim 7, wherein the image produced by the vision engine has a light dynamic range of greater than 4000:

1.

11. The automated inspection system method of claim 3, wherein said monitor is a high dynamic range display device.

12. The automated inspection system method of claim 7, wherein said vision engine utilizes a tone-mapping technique to convert the tonal values of said combined image.

13. The automated inspection system method of claim 7, further comprising a light meter to measure luminance values of a scene containing said golf ball.

14. The method of claim 4, wherein a camera includes the at least two photosensitive pixel array image sensors and wherein the array of pixels of each image sensor absorbs light to a different degree.

15. The method of claim 14, wherein said vision engine employs an algorithmic image combining process to blend the images produced by each of the image sensors into one image having high light dynamic range.

16. The method of claim 15, wherein said camera includes three photosensitive pixel array image sensors.

17. The method of claim 15, wherein each image sensor is a charged-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) sensor.

18. The method of claim 15, wherein said camera further comprises a beam splitter to direct photons to each of the image sensors.

19. The automated inspection system method of claim 15, wherein said camera includes a number of half-silvered mirrors to direct photons to each of the image sensors.