ANALYSIS OF THE DIGITAL IMAGE OF THE EXTERNAL SURFACE OF A TYRE AND PROCESSING OF FALSE MEASUREMENT POINTS

• US 20140307941A1
• Filed: 03/21/2012
• Published: 10/16/2014
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: Compagnie générale des établissements Michelin, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Original Assignee: Compagnie générale des établissements Michelin, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Zanella, Jean-Paul, Noyel, Guillaume, Moreau, Claire, Shen, Yusi
• Granted Patent: US 9,230,318 B2
• Time in Patent Office: Days
• US Class Current: 382/141
• CPC Class Codes: G01M 17/027 using light, e.g. infrared, ultraviolet or holographic techniques
• CPC Class Codes: G01N 21/952 Inspecting the exterior surface of cylindrical bodies or wires G01N21/956 takes precedence
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/20036 Morphological image processing
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 3/10 Selection of transformation methods according to the characteristics of the input images
• CPC Class Codes: G06T 5/30 Erosion or dilatation, e.g. thinning
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/001 using an image reference approach

Abstract

Method for processing the three-dimensional digital image of the surface of a tyre in which the three-dimensional image of the said surface is captured while assigning to each pixel of the plane of the image an item of information relating to the elevation of this point with respect to the surface to be inspected, characterized in that, with the aid of a morphological operator using a structuring element, a first transformation of the image of the surface is performed with the aid of an opening and then of a closing, so as to tailor the grey level of the pixels situated abnormally above or below the surface to be inspected.

Claims

1-5. -5. (canceled)

6. A method for processing an image of a surface of a tyre, in which a three-dimensional digital image of the surface is captured, in which each pixel of a plane of the image is assigned an item of information relating to an elevation of the pixel with respect to the surface, the method comprising steps of:

utilizing a morphological operator that includes an opening and a closing and that uses a structuring element of given size and shape to perform a first transformation of the image of the surface so as to tailor a grey level of pixels situated abnormally above or below the surface;

determining elements of contours of relief of the surface using a gradient-type morphological operator, and then performing a thresholding operation to extract the contours of the relief of the surface; and

performing a second transformation of the image of the surface by assigning to each pixel of a contour a value of a grey level equal to a value obtained from the first transformation.

7. The method according to claim 6, wherein a grey level of a pixel is representative of an elevation of a corresponding point of the surface.

8. The method according to claim 6, wherein the morphological operator is a square.

9. The method according to claim 7, wherein the morphological operator is a square.

10. The method according to claim 8, wherein a width of the square of the morphological operator lies between 8 and 15 pixels.

11. The method according to claim 9, wherein a width of the square of the morphological operator lies between 8 and 15 pixels.

12. The method according to claim 6, wherein the image is that of an external surface of the tyre.

13. The method according to claim 7, wherein the image is that of an external surface of the tyre.

14. The method according to claim 8, wherein the image is that of an external surface of the tyre.

15. The method according to claim 9, wherein the image is that of an external surface of the tyre.

16. The method according to claim 10, wherein the image is that of an external surface of the tyre.

17. The method according to claim 11, wherein the image is that of an external surface of the tyre.