Artifact mitigation in three-dimensional imaging

• US 7,742,635 B2
• Filed: 09/22/2006
• Issued: 06/22/2010
• Est. Priority Date: 09/22/2005
• Status: Expired due to Fees

• Current Assignee: 3M Company
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Zhang, Tong, Rohaly, Janos, Hart, Douglas P.
• Primary Examiner(s): Hung; Yubin
• Application Number:
  US11/534,570
• Publication Number:
  US 20070075997A1
• Time in Patent Office: 1,369 Days
• Field of Search: 382/106, 382/154, 348/42, 348 47- 51
• US Class Current: 382/154
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 2207/30036 Dental; Teeth
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
• CPC Class Codes: G06T 7/85 Stereo camera calibration

Abstract

Accuracy of a three-dimensional imaging system is improved through the use of model-based calibration and lookup tables to resolve distance according to, e.g., x-displacement, y-displacement, or image disparity data. In an embodiment, the lookup table(s) stores localized parameterization data used to calculate calibrated results.

Claims

1. A method for refining calibration of an imaging system comprising:

acquiring image data with the imaging system from a measurement volume that includes a three-dimensional object having one or more known parameters;

identifying a first projection contour of the three-dimensional object in the image data;

analytically determining a second projection contour of the three-dimensional object using the one or more known parameters and a model of the imaging system;

refining a calibration of the imaging system by minimizing a deviation between the first projection contour and the second projection contour; and

storing the calibration in the imaging system for use in recovering calibrated coordinates during a three-dimensional scan.

2. The method of claim 1 wherein the three-dimensional object is a sphere and the one or more known parameters includes a radius of the sphere.