Three-dimensional surface/contour processing based on electromagnetic radiation interrogation

• US 20060066469A1
• Filed: 09/24/2004
• Published: 03/30/2006
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: McMakin, Douglas L., Hall, Thomas E., Foote, Harlan P.
• Granted Patent: US 7,253,766 B2
• Time in Patent Office: Days
• US Class Current: 342/22
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics
• CPC Class Codes: G06T 2207/20168 Radial search
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 2219/008 Cut plane or projection plane definition
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/149 involving deformable models, e.g. active contour models
• CPC Class Codes: G06T 7/168 involving transform domain methods

Abstract

One embodiment of the present invention includes scanning a target with electromagnetic radiation including one or more frequencies in a range of about 200 MHz to about 1 THz; establishing a point cloud representation of the surface of the target from the scan; and performing one or more curve-fitting operations as a function of at least a portion of the points of the point cloud representation to represent at least a portion of the surface of the target.

Claims

1. A method, comprising:

interrogating a person at least partially covered by clothing with electromagnetic radiation including one or more frequencies in a range of about 200 MHz to about 1 THz;

establishing spatially varying data corresponding to a three-dimensional representation of a surface beneath the clothing based on said interrogating;

selecting a cross-sectional region of the representation; and

defining a number of points representative of a contour of the surface beneath the clothing as a function of spatial variation of the data along a corresponding one of a number of reference axes extending through the cross-sectional region.

2. The method of claim 1, wherein the cross-sectional region corresponds to a sectional plane, the reference axes each correspond to a line segment coplanar with the sectional plane, and at least a portion of the reference axes are approximately parallel to one another.

3. The method of claim 1, wherein the cross-sectional region corresponds to a sectional plane, the reference axes each correspond to a radial line segment extending from an origin and coplanar to the sectional plane, and the contour at least partially surrounds the origin.

4. The method of claim 3, wherein the origin is coincident with a line segment of a skeletal vector model.

5. The method of claim 1, which includes performing a curve-fitting operation to define the contour.

6. The method of claim 5, which includes determining a dimension of the contour.

7. The method of claim 5, wherein the curve-fitting operation includes elliptical curve fitting.

8. The method of claim 7, which includes performing fourier boundary fitting.

9. The method of claim 1, wherein said establishing includes combining a number of data sets, the data sets each corresponding to a different cylindrical image of the person from a different view.

10. A method, comprising:

scanning a person at least partially covered by clothing with electromagnetic radiation including one or more frequencies in a range of about 200 MHz to about 1 THz;

establishing a point cloud representation of a surface beneath the clothing of the person from said scanning; and

performing one or more curve-fitting operations as a function of at least a portion of the points of the point cloud representation to represent at least a portion of the surface beneath the clothing.

11. The method of claim 10, wherein the one or more curve-fitting operations includes elliptical curve fitting.

12. The method of claim 10, wherein the one or more curve-fitting operations includes fourier boundary fitting.

13. The method of claim 10, wherein said establishing includes:

generating data representative of a topographical image of the person from electromagnetic radiation returned by said scanning;

evaluating subsets of the data, the subsets each corresponding to one of a number of different two-dimensional cross sections of the person, the subsets each including a varying degree of uncertainty with respect to position of the surface; and

for each of the subsets, determining a point of the point cloud representation of the surface as a function of the electromagnetic radiation returned relative to a different one of a number of reference axes.

14. The method of claim 10, wherein said performing includes defining a number of contours of the surface and determining a dimension of each of the contours.

15. The method of claim 14, wherein said one or more curve fitting operations include elliptical curve fitting and fourier boundary fitting, and further comprising determining a number of contours corresponding to a skeletal vector model.

21. The method of claim 14, wherein the one or more curve fitting operations include at least one of elliptical curve fitting and fourier boundary fitting, and further comprising determining the contours in correspondence to one or more of a number of line segments of a skeletal vector model.

16. A method, comprising:

scanning a target with electromagnetic radiation including one or more frequencies in a range of about 200 MHz to about 1 THz;

from said scanning, determining data corresponding to a topographical representation of the target, the topographical representation having a varying degree of spatial uncertainty with respect to position of a surface of the target; and

generating a three-dimensional point cloud representation of the surface of the target from the data, the point cloud representation including a number of points each determined by evaluating spatial variation of the data for a different portion of the topographical representation.

17. The method of claim 16, wherein said generating includes:

evaluating subsets of the data, the subsets each corresponding to one of a number of different two-dimensional sections of the target; and

for each of the subsets, determining one of the points of the point cloud representation of the surface as a function of one or more reference axes extending along a respective one of the two-dimensional sections and electromagnetic radiation returned by the target along the one or more reference axes in response to said scanning.

18. The method of claim 17, which includes generating the data from the electromagnetic radiation returned by the target from each of a number of views, the data for each of the views corresponding to a cylindrical image of the target.

19. The method of claim 16, wherein the target is a person in an interrogation area and at least a portion of the surface represented by the point cloud representation corresponds to skin of the person beneath clothing.

20. The method of claim 16, which includes defining a number of contours of the surface by performing one or more curve-fitting operations.

22. A method, comprising:

irradiating an interrogation region including a person at least partially covered by clothing;

detecting electromagnetic radiation returned from the interrogation region in response to said irradiating, the electromagnetic radiation including one or more frequencies in a range of about 200 MHz to about 1 THz; and

rendering a surface beneath the clothing based on a skeletal vector model, the skeletal vector model including a number of line segments corresponding to different body portions of the person.

23. The method of claim 22, wherein said rendering includes determining a point cloud representation of the surface as a function of the skeletal vector model and a number of reference axes.

24. The method of claim 23, wherein said rendering includes determining a number of contours of the surface by performing one or more curve fitting operations, the curve fitting operations including at least one of elliptical curve fitting and fourier boundary fitting.

25. The method of claim 22, wherein said rendering includes:

evaluating a sectional region selected relative to one of the line segments of the skeletal vector model;

determining each of a number of points representative of the surface from a different reference axis and the electromagnetic radiation returned from the interrogation region along the different reference axis; and

defining a surface contour for the sectional region from the number of points.

26. The method of claim 25, wherein the sectional region, the number of points, and the reference axis are coplanar.

27. The method of claim 22, wherein the line segments include one or more corresponding to each arm of the person, one or more corresponding to each leg of the person, and one or more corresponding to a trunk of the person.

28. A system, comprising:

an array operable to interrogate a person at least partially covered by clothing with electromagnetic radiation at one or more frequencies in a range of about 200 MHz to about 1 THz;

a processing subsystem coupled to the array, the processing subsystem being operable to establish spatially varying data corresponding to a three-dimensional representation of a surface beneath the clothing based on data generated in response to interrogation of the person with the array, the processing subsystem being further operable to evaluate a cross-sectional region of the representation and define a number of points representative of a contour of the surface beneath the clothing as a function of spatial variation of the data, the points each corresponding to one of a number of reference axes extending along the cross-sectional region; and

an output device responsive to the processing subsystem to provide an output at least partially based on the contour.

29. The system of claim 28, further comprising means for performing one or more curve-fitting operations to define the contour.

30. The system of claim 28, wherein the output device is operable to provide at least one dimension of the contour.

31. The system of claim 28, wherein the processing subsystem is further operable to determine a plurality of different surface contours and provide a measurement of each of the different surface contours based on the interrogation with the array.

32. The system of claim 31, wherein the processing subsystem further comprises means for determining each of the different surface contours as a function of a point cloud representation of the surface including the number of points and a skeletal vector model.

33. The system of claim 28, wherein the array is one of two arrays, the arrays each being arranged in a different one of two respective panels positioned opposite each other.

34. The system of claim 28, further comprising means for moving at least one of the array and the person relative to another.

35. The system of claim 28, wherein the moving means rotates the at least one of the array and the person.

36. An apparatus, comprising:

a device carrying logic executable by one or more processors operable to control scanning of a target with electromagnetic radiation including one or more frequencies in a range of about 200 MHz to about 1 THz and establish data corresponding to a topographical representation of the target based on the scanning of the target, the topographical representation having a varying range of spatial uncertainty with respect to position of a surface of the target;

the logic being further executable to generate a point cloud representation of the surface of the target from the data by performing an evaluation of each of a number of subsets of the data, the subsets each corresponding to one of a number of different two-dimensional regions of the target; and

for each of the subsets, the logic being executable to determine a point of the point cloud representation of the surface as a function of one or more reference axes extending along a respective one of the two-dimensional regions and a measurement of electromagnetic radiation returned by the target along the one or more reference axes in response to the scanning.

37. The apparatus of claim 36, wherein the device is in the form of a processor-readable memory and the logic is in the form of a number of instructions stored in the memory.

38. The apparatus of claim 36, wherein the device includes one or more parts of a computer network and the logic is encoded in one or more signals for transmission over the computer network.