Method and device for automatically identifying a point of interest on the surface of an anomaly

Patent metadata

Field	Value
Publication number	US-9600928-B2
Application number	US-201414512835-A
Country	US
Kind code	B2
Filing date	Oct 13, 2014
Priority date	Dec 17, 2013
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A method and device for automatically identifying a point of interest (e.g., the deepest or highest point) on the surface of an anomaly on a viewed object using a video inspection device is disclosed. The video inspection device obtains and displays an image of the surface of the viewed object. A reference surface is determined along with a region of interest that includes a plurality of points on the surface of the anomaly. The video inspection device determines a depth or height for each of the plurality of points on the surface of the anomaly in the region of interest. The point on the surface of the anomaly (e.g., having the greatest depth or height) is identified as the point of interest. A profile of the object surface at the point of interest is then determined.

First claim

What is claimed is:

1. A method of automatically identifying a point of interest on a surface of an anomaly on an object surface of a viewed object, the method comprising the steps of:
displaying on a monitor an image of the object surface;
determining the three-dimensional coordinates of a plurality of points on the object surface using a central processor unit;
selecting a first reference line endpoint on a first pixel of the image using a pointing device;
selecting a second reference line endpoint on a second pixel of the image using the pointing device;
determining the three-dimensional coordinates of a plurality of points on a first reference line extending between the first reference line endpoint and the second reference line endpoint using the central processor unit;
selecting a third reference line endpoint on a third pixel of the image using the pointing device;
selecting a fourth reference line endpoint on a fourth pixel of the image using the pointing device;
determining the three-dimensional coordinates of a plurality of points on a second reference line extending between the third reference line endpoint and the fourth reference line endpoint using the central processor unit;
determining a reference surface based on the three-dimensional coordinates of at least two of the plurality of points on the first reference line and at least one of the plurality of points on the second reference line using the central processor unit;
determining a region of interest for the reference surface that comprises a plurality of points on the surface of the anomaly using the central processor unit;
determining the distances between the reference surface and the plurality of points on the surface of the anomaly in the region of interest using the central processor unit;
determining the three-dimensional coordinates of the point of interest on the surface of the anomaly in the region of interest having the greatest distance from the reference surface using the central processor unit;
determining the three-dimensional coordinates of a plurality of points of a profile surface contour line on the object surface between the first reference line and the second reference line including the point of interest on the surface of the anomaly using the central processor unit; and
determining a profile of the object surface by determining the distance from the reference surface to the plurality of points of the profile surface contour line on the object surface using the central processor unit.

2. The method of claim 1 , wherein the step of determining the three-dimensional coordinates of the plurality of points on the first reference line comprises:
determining a first reference line plane intersecting the object surface and passing through the first reference line endpoint and the second reference line endpoint; and
determining the three-dimensional coordinates of a plurality of points of a first surface contour line on the object surface proximate to the first reference line plane.

3. The method of claim 1 , wherein the first reference line is straight.

4. The method of claim 1 , wherein the reference surface is a reference plane.

5. The method of claim 1 , wherein the step of determining a region of interest for the reference surface comprises determining a polygon on the reference surface with vertices based on the at least two of the plurality of points on the first reference line and the at least one of the plurality of points on the second reference line, wherein the region of interest comprises a plurality of points on the surface of the anomaly that lie on lines normal to the reference surface and that intersect the reference surface within the polygon.

6. The method of claim 1 , wherein the step of determining a region of interest for the reference surface comprises determining a region of interest plane intersecting the reference surface and passing through the first reference line in between the at least two of the plurality of points on the first reference line, wherein the region of interest comprises a plurality of points on the surface of the anomaly that lie within a predetermined distance of the region of interest plane.

7. The method of claim 1 , further comprising the step of displaying on the monitor a graphical representation of the profile of the object surface comprising a cross-section of the viewed object at the profile surface contour line.

8. The method of claim 1 , further comprising the step of displaying on the monitor the distance between the reference surface and the point of interest on the surface of the anomaly.

9. The method of claim 1 , further comprising the step of displaying on the monitor a point cloud image comprising a three-dimensional representation of the profile surface contour line.

10. The method of claim 1 , wherein the image is a two-dimensional image.

11. The method of claim 1 , wherein the step of determining the three-dimensional coordinates of the plurality of points on the first reference line comprises performing regression on the three-dimensional coordinates of points on the object surface corresponding to pixels of the image proximate to a straight line between the first pixel and the second pixel.

12. The method of claim 1 , wherein the step of determining the three-dimensional coordinates of the plurality of points on the first reference line comprises performing low-pass filtering on the three-dimensional coordinates of points on the object surface corresponding to pixels of the image proximate to a straight line between the first pixel and the second pixel.

13. The method of claim 1 , wherein the profile surface contour line on the object surface comprises a first point on or proximate to the first reference line and a second point on or proximate to the second reference line.

14. The method of claim 6 , wherein region of interest plane intersects the reference surface normal to the reference surface.

15. A device for automatically identifying a point of interest on a surface of an anomaly on an object surface of a viewed object, the device comprising:
a monitor for displaying an image of the object surface;
a pointing device for
selecting a first reference line endpoint on a first pixel of the image,
selecting a second reference line endpoint on a second pixel of the image,
selecting a third reference line endpoint on a third pixel of the image, and
selecting a fourth reference line endpoint on a fourth pixel of the image; and

a central processor for
determining the three-dimensional coordinates of a plurality of points on the object surface,
determining the three-dimensional coordinates of a plurality of points on a first reference line extending between the first reference line endpoint and the second reference line endpoint,
determining the three-dimensional coordinates of a plurality of points on a second reference line extending between the third reference line endpoint and the fourth reference line endpoint,
determining a reference surface based on the three-dimensional coordinates of at least two of the plurality of points on the first reference line and at least one of the plurality of points on the second reference line,
determining a region of interest for the reference surface that comprises a plurality of points on the surface of the anomaly,
determining the distances between the reference surface and the plurality of points on the surface of the anomaly in the region of interest,
determining the three-dimensional coordinates of the point of interest on the surface of the anomaly in the region of interest having the greatest dis

Assignees

• Gen Electric

Inventors

• Bendall Clark Alexander
• Stancato Melissa Rose
• Ball Michael Melvin

Classifications

• G01B13/22

  for measuring roughness or irregularity of surfaces · CPC title

• G06T2207/20096

  Interactive definition of curve of interest · CPC title

• G06T17/00 Primary

  Three-dimensional [3D] modelling for computer graphics · CPC title

• G01N2021/8887

  based on image processing techniques · CPC title

• G06T7/50

  Depth or shape recovery · CPC title