Method for inspecting channel pipes

• US 20060062444A1
• Filed: 01/24/2003
• Published: 03/23/2006
• Est. Priority Date: 03/28/2002
• Status: Abandoned Application

• Current Assignee: Ibak Helmut Hunger GmbH & Co. KG
• Original Assignee: Ibak Helmut Hunger GmbH & Co. KG
• Inventors: Rehse, Heino
• Application Number:
  US10/509,167
• Publication Number:
  US 20060062444A1
• Time in Patent Office: Days
• US Class Current: 382/141
• CPC Class Codes: F16L 2101/30 Inspecting, measuring or testing
• CPC Class Codes: G01M 3/38 by using light G01M3/02 takes precedence
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 5/006 Geometric correction correction of chromatic aberrations adapted to be used in an image pickup device containing an electronic image sensor H04N23/10; detecting, correcting, reducing or removing artefacts resulting only from the lens unit, e.g. flare, shading, vignetting or "cos4" H04N25/61
• CPC Class Codes: G06T 5/80 Geometric correction
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

The invention relates to a method for inspecting channel pipes, wherein hemispherical or fully spherical digital images captured at various locations in the pipe by means of a camera provided with a fisheye lens are calculated and perspective images enabling a virtual swiveling are produced. The intermediate images arising for any specific neighboring location of the desired fictive camera position are calculated and represented on the basis of image data captured in a location wherein the geometry of the imaged pipe is known, by computationally projecting the captured images onto the known pipe geometry and calculating the perspective image data therefrom for the neighboring location.

Claims

1-3. -3. (canceled)

4. A method for inspecting channel pipes, wherein hermispherical or fully spherical digital images recorded at specific locations in the pipe are calculated and perspective images enabling virtual swiveling are produced, the method comprising:

taking a known geometry of an imaged pipe from an image data at one location;

calculating and representing an intermediate image for a random neighboring location of a desired fictive camera position;

projecting a recorded image computationally onto the known pipe geometry; and

calculating a perspective image data resulting therefrom for a neighboring location.

5. The method according to claim 4, wherein calculating at each image point of a 2D-fisheye image P′

(Xf, Yf) with known imaging function, the angle of incidence (α

, θ

) of the spherical coordinates, and from the calculation a corresponding image point in 3D space P(Xr, Yr, Zr) on the pipe surface is represented.

6. The method according to claim 4, wherein calculating from the desired fictive camera position and its viewing angle in space, an image point located in a desired section of an image plane, and taking from image point coordinates (Xb, Yb) of the image plane and assuming a projection center at a distance F from the image plane B, calculating corresponding image point coordinates (Xr, Yr, Zr) on the inner surface of the known pipe geometry and corresponding image point coordinates (Xf, Yf) of a fisheye image, so that the color and brightness value of an image point on image plane B with P″

(Xb, Yb)=P(Xf, Yf) is obtained.