Integrated system for quickly and accurately imaging and modeling three-dimensional objects

• US 6,473,079 B1
• Filed: 10/23/1998
• Issued: 10/29/2002
• Est. Priority Date: 04/24/1996
• Status: Expired due to Term

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Cyra Technologies, Inc. (Hexagon AB)
• Inventors: Kung, Jonathan Apollo, Thewalt, Christopher Robin, Dimsdale, Jerry, Kacyra, Ben K., Brunkhart, Mark
• Primary Examiner(s): Nguyen, Phu K.
• Application Number:
  US09/177,777
• Time in Patent Office: 1,467 Days
• Field of Search: 345/418, 345/419, 345/619, 345/606, 345/620, 345/629, 345/630
• US Class Current: 345/419
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4818 using optical fibres

Abstract

An integrated system generates a model of a three-dimensional object. A scanning laser device scans the three-dimensional object and generates a point cloud. The points of the point cloud each indicate a location of a corresponding point on a surface of the object. A first model is generated, responsive to the point cloud, that generates a first model representing constituent geometric shapes of the object. A data file is generated, responsive to the first model, that can be inputted to a computer-aided design system.

Claims

1. A method for automatically segmenting a scan field of a scene into subsets of points that represent different surfaces in the scene, comprising the steps of:

separating the scan field into a depth grid that includes depth information for scanned points of surfaces in the scene and a normal grid that includes an estimate of a normal to scanned points of the surfaces;

convolving the depth information of the depth grid to generate a depth rating image whose values represent a gradient of depth change from one scanned point to another scanned point in the scene;

convolving the components of the normal grid to generate a scalar value for each component for each point of the normal grid,

for each point of the normal grid, determining from the scalar values for the components of that particular point a gradient of the normal at that point, wherein the gradients determined for the points of the normal grid collectively constitute a normal rating image;

converting the depth rating image to a binary depth image using a recursive thresholding technique;

converting the normal rating image to a binary normal image using a recursive thresholding technique;

combining the binary depth image and the binary normal image to determine a single edge image; and

grouping subsets of non-edge points as belonging to corresponding surfaces of the scene.

2. A method as recited in claim 1 further including the steps of:

determining the type of geometric primitive that would best first each group of points; and

fitting the geometric primitive to the data points.

3. A method as recited in claim 2 further including the step of intersecting adjacent planar regions in the scene.

4. A method of warping, comprising:

selecting one or more models represented by a plurality of point clouds and geometric primitives;

specifying constraints on the locations of any number of points or geometric primitives;

creating an artificial volume that surrounds the points and geometric primitives in each view and assigning mechanical material characteristics to the surrounding volume;

computing a minimum energy configuration for the material in the surrounding volume in which the points or geometric primitives are embedded such that the configuration satisfies all applied constraints; and

displacing the points and primitives in accordance with the computed minimum energy configuration of the surrounding volume of material.

5. The method of claim 4, wherein the constraints are specified to eliminate closure errors.