Method and apparatus for performing geo-spatial registration of imagery

• US 20010038718A1
• Filed: 03/09/2001
• Published: 11/08/2001
• Est. Priority Date: 05/09/1997
• Status: Active Grant

• Current Assignee: SRI International, Inc.
• Original Assignee: Sarnoff Corporation (SRI International, Inc.)
• Inventors: Hirvonen, David James, Zhao, Wenyi, Wildes, Richard Patrick, Klinedinst, Thomas Edward, Levienaise-Obadia, Barbara, Lehman, William Brian, Matei, Bodgan, Samarasekera, Supun, Kumar, Rakesh, Hanna, Keith, Hsu, Stephen Charles
• Granted Patent: US 6,597,818 B2
• Time in Patent Office: Days
• US Class Current: 382/284
• CPC Class Codes: G06T 3/153 using elastic snapping
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images
• CPC Class Codes: G06T 7/35 using statistical methods
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A system and method for accurately mapping between image coordinates and geo-coordinates, called geo-spatial registration. The system utilizes the imagery and terrain information contained in the geo-spatial database to precisely align geodetically calibrated reference imagery with an input image, e.g., dynamically generated video images, and thus achieve a high accuracy identification of locations within the scene. When a sensor, such as a video camera, images a scene contained in the geo-spatial database, the system recalls a reference image pertaining to the imaged scene. This reference image is aligned very accurately with the sensor'"'"'s images using a parametric transformation. Thereafter, other information that is associated with the reference image can easily be overlaid upon or otherwise associated with the sensor imagery.

Claims

1. A system for performing geo-spatial registration of an input image and geodetically calibrated reference imagery comprising:

a reference database module containing geodetically calibrated reference imagery for producing reference imagery relating to imagery in said input image;

a preprocessor for processing the input image and said reference imagery using an oriented filter; and

an alignment module for aligning said preprocessed input image and said preprocessed reference imagery.

2. The system of

claim 1

wherein said input image is an image mosaic.

3. The system of

claim 1

further comprising:

an outlier rejection module for removing inaccurate correlations between said preprocessed input image and said preprocessed reference image.

4. The system of

claim 1

wherein said alignment module registers said preprocessed input image to said preprocessed reference imagery.

5. The system of

claim 1

wherein said alignment module registers said preprocessed reference imagery to said preprocessed input image.

6. The system of

claim 1

wherein said alignment module performs oriented matching to align said preprocessed input image and said preprocessed reference imagery.

8. The system of

claim 6

wherein said input image is an image mosaic.

9. The system of

claim 6

wherein said alignment module registers said preprocessed input image to said preprocessed reference imagery.

10. The system of

claim 6

wherein said alignment module registers said preprocessed reference imagery to said preprocessed input image.

11. The system of

claim 6

wherein said alignment module performs oriented matching to align said preprocessed input image and said preprocessed reference imagery.

7. A system for performing geo-spatial registration of an input image and geodetically calibrated reference imagery comprising:

a reference database module containing geodetically calibrated reference imagery for producing reference imagery relating to imagery in said input image;

an alignment module for aligning said preprocessed input image and said preprocessed reference imagery through feature correlation; and

an outlier rejection module for removing inaccurate feature correlations between said preprocessed input image and said preprocessed reference image.

12. A system for performing geo-spatial registration of an input image and geodetically calibrated reference imagery comprising:

a reference database module containing geodetically calibrated reference imagery for producing reference imagery relating to imagery in said input image;

an alignment module for aligning said preprocessed input image and said preprocessed reference imagery by performing oriented matching of features in said preprocessed input image and said preprocessed reference imagery.

13. The system of

claim 12

wherein said input image is an image mosaic.

14. The system of

claim 12

further comprising:

an outlier rejection module for removing inaccurate feature correlations between said preprocessed input image and said preprocessed reference image.

15. The system of

claim 12

wherein said alignment module registers said preprocessed input image to said preprocessed reference imagery.

16. The system of

claim 12

wherein said alignment module registers said preprocessed reference imagery to said preprocessed input image.

17. A system for performing geo-spatial registration of a sequence of input images and geodetically calibrated reference imagery comprising:

a reference database module containing geodetically calibrated reference imagery for producing reference imagery relating to imagery in said input images;

an alignment module for simultaneously aligning a plurality of input images from said sequence of input images to said reference imagery.

18. The system of

claim 17

further comprising:

a preprocessor module for orientation filtering said reference imagery and said input images.

19. The system of

claim 18

wherein the preprocessor module further comprises an interframe alignment module.

20. The system of

claim 17

wherein said alignment module further comprises:

a coarse alignment module for coarsely aligning said reference imagery and said input images.

21. The system of

claim 20

wherein said alignment module further comprises:

a fine alignment module for accurately aligning said coarsely aligned input images and said reference image.

22. The system of

claim 17

wherein said alignment module further comprises a synthetic view generation block for warping said reference imagery to have a viewpoint similar to a viewpoint of a sensor that produced said input images.

23. The system of

claim 17

wherein said alignment module comprises:

a local matching module for aligning a plurality of said input images to one another; and

a global matching module for simultaneously aligning the aligned plurality of input images and the reference image.

24. The system of

claim 17

further comprising:

an outlier rejection module.

25. A method for performing geo-spatial registration of an input image and geodetically calibrated reference imagery comprising:

producing reference imagery relating to imagery in said input image;

processing the input image and said reference imagery using an oriented filter; and

aligning said processed input image and said processed reference imagery.

26. The method of

claim 25

wherein said input image is an image mosaic.

27. The method of

claim 25

further comprising:

correlating said processed input image with said processed reference imagery;

removing inaccurate correlations between said preprocessed input image and said preprocessed reference image.

28. A method for performing geo-spatial registration of a sequence of input images and geodetically calibrated reference imagery comprising:

producing reference imagery relating to imagery in said input images;

simultaneously aligning a plurality of input images from said sequence of input images to said reference imagery.