SCALABLE METHOD FOR RAPIDLY DETECTING POTENTIAL GROUND VEHICLE UNDER COVER USING VISUALIZATION OF TOTAL OCCLUSION FOOTPRINT IN POINT CLOUD POPULATION

• US 20080123961A1
• Filed: 07/10/2007
• Published: 05/29/2008
• Est. Priority Date: 09/19/2003
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Nelson, James M.
• Granted Patent: US 8,294,712 B2
• Time in Patent Office: Days
• US Class Current: 382/190
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes

Abstract

Techniques for facilitating detection of an object in a point cloud of three-dimensional imaging data representing an area of study where the object potentially is obscured by intervening obstacles are provided. The imaging data is processed to identify elements in the point cloud having substantially common attributes signifying that the identified elements correspond to a feature in the area of study. An isosurface is generated associating the elements having substantially common attributes. A reversed orientation visualization model for a region of interest is generated. The reversed orientation visual model areas of total occlusion that potentially signify presence of the object.

Claims

1. A method of detecting a possible presence in an area of study of a ground-level object, the method comprising:

gathering a point cloud of three-dimensional imaging data representing the area of study from an aerial position where an intervening obstacle impedes a line of sight between the aerial position and a ground-level object;

processing the imaging data to identify elements in the point cloud having substantially common attributes signifying that the identified elements correspond to a feature in the area of study that is at least partially obscured by the intervening obstacle;

generating at least one isosurface associating the elements having substantially common attributes;

selecting a region of interest from the area of study;

generating from the imaging data gathered from the aerial position an up from underground oriented visualization model of the region of interest; and

displaying the up from underground oriented visualization model exposing the feature in the area of study that is at least partially obscured by the intervening obstacle in the line of sight between the aerial position and the ground-level object.

2. The method of claim 1, wherein the three-dimensional imaging data of the area of study is gathered using ladar.

3. The method of claim 1, wherein imaging data is processed using a population function computed on a sampling mesh by a Fast Binning Method (FBM).

4. The method of claim 1, wherein the isosurface of the population function is computed using a marching cubes method.

5. The method of claim 1, further comprising allowing an operator to manually select the region of interest from the area of study.

6. The method of claim 1, wherein the up from underground oriented visualization model exposes areas of total ground occlusion.

7. The method of claim 1, further comprising regenerating the up from underground oriented visualization model using interactive user input from a slider resolution control.

8. The method of claim 7, wherein the slider resolution control dynamically regenerates the up from underground oriented visualization model when a user changes the slider resolution control position.

9. The method of claim 1, wherein the up from underground oriented visual model disambiguates areas of total ground occlusion from porous ground occluders.

10. A method, comprising:

viewing a reversed orientation visualization model of an isosurface;

selecting a region of interest from the reversed orientation visualization model;

viewing the region of interest of the isosurface as a top-down orientation visualization model;

selectively varying the point resolution of the region of interest to adjust the isosurface sampling resolution; and

identifying an object within the isosurface.

11. The method of claim 10, wherein the isosurface includes an area of partial ground occlusion and an area of total ground occlusion, the area of total ground occlusion depicted as a cavity within the isosurface when viewed in the revered orientation visualization model.

12. The method of claim 10, wherein selecting the region of interest includes selecting the cavity with the isosurface.

13. The method of claim 10, wherein selectively varying the point resolution includes user interaction with a slider control.

14. The method of claim 10, wherein identifying an object within the isosurface includes identifying a target that is at least partially obscured in a top-down image.

15. The method of claim 10, wherein the isosurface is generated from a point cloud population generated from ladar.

16. A user interface, comprising:

a display portion configured to display an isosurface formed from a point cloud population, the point cloud population having a sampling resolution; and

a control portion facilitating manipulation of the display portion, the control portion including a resolution control to adjust the sampling resolution of the point cloud population forming the isosurface, the resolution control providing user interactive modification of the isosurface display.

17. The user interface of claim 16, wherein the resolution control dynamically updates the isosurface based on user interaction.

18. The user interface of claim 16, wherein the display portion is configured to initially display an automatically selected isosurface level.

19. The user interface of claim 18, wherein the control portion further comprises a focus control to adjust the automatically selected isosurface level.

20. The user interface of claim 16, wherein the display portion is configured to display elevation of the isosurface.