System and method for mosaicing digital ortho-images

• US 20100020097A1
• Filed: 08/05/2009
• Published: 01/28/2010
• Est. Priority Date: 09/19/2002
• Status: Active Grant

• Current Assignee: VI Technologies, LLC (VI GP LLC (f/k/a M7 Visual Intelligence GP LLC))
• Original Assignee: M7 Visual Intelligence, LP
• Inventors: Smitherman, Chester L, Mai, Tuy Vu
• Granted Patent: US 7,925,114 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images

Abstract

The present invention provides a system and method for mosaicing multiple input images, captured by one or more remote sensors, into a seamless mosaic of an area of interest. Each set of input images captured by the remote sensors within a capture interval are ortho-rectified and mosaiced together into a composite image. Successive composite images, along a given flight path, are then mosaiced together to form a strip. Adjacent strips are then mosaiced together to form a final image of the area of interest.

Claims

1. A system residing on a computer readable medium for rendering multiple input images into a single composite image, comprising:

a first system for performing initial processing on each input image;

a second system for determining geographical boundaries of each input image, cooperatively engaged with the first system;

a third system for mapping each input image into the composite image with accurate geographical position, cooperatively engaged with the first and second systems,

a fourth system for balancing color intensity of the mapped input images into the composite image, cooperatively engaged with the first, second and third systems;

a fifth system for blending borders between adjacent input images mapped into the composite image, cooperatively engaged with the first, second, third and fourth systems, wherein multiple input images are reduced to a transformation matrix in a single transformation; and

a sixth system for establishing a seam line between adjacent images, cooperatively engaged with the first, second, third, fourth and fifth systems, wherein the seam line is altered based upon a position of an elevated feature.

2. The system of claim 1, wherein each system is implemented in a separate functional instance.

3. The system of claim 1, wherein a plurality of the systems are implemented in a single functional instance.

4. The system of claim 1, wherein each system is implemented in software.

5. The system of claim 1, wherein each system is implemented in hardware.

6. The system of claim 1, wherein the systems are implemented in a combination of hardware and software.

7. The system of claim 1, wherein the system for mapping each input image further comprises a super-sampling system.

8. The system of claim 1, where at least two single transformation matrices are reduced to a single transformation matrix.

9. The system of claim 1, wherein the first system performs a white balancing process on the input images.

10. The system of claim 1, wherein the first system performs an anti-vignetting process on the input images.

11. The system of claim 1, further comprising a sixth system for controlling the exposure time of the input images based on image intensity, cooperatively engaged with the first, second, third, fourth and fifth systems.

12. The system of claim 12, wherein the system for controlling the exposure time of the input images based on image intensity is incorporated within the fourth system for balancing color of the input images.

13. The system of claim 12, wherein the system for controlling the exposure time of the input images based on image intensity focuses on green-dominant pixels.

14. A method of geographically aligning a plurality of input images of a target terrain collected from an imaging sensor, comprising the steps of:

determining the imaging sensor'"'"'s attitude with respect to a target terrain;

providing a primary input image and at least one secondary image;

aligning the primary input image with respect to the target terrain;

aligning the secondary input image with respect to the primary input image;

establishing a seam line between adjacent images; and

altering the seam line based upon a position of an elevated feature.

15. A method of mosaicing two overlapping digital input images together to form an output image, comprising the steps of:

providing a reference image, comprising a number of green-dominant pixels having certain average color intensity and average elevation;

providing a secondary image, comprising a number of green-dominant pixels having certain average color intensity and average elevation, that overlaps the reference image in an overlap area;

scaling pixel values of the secondary image within the overlap area such that the color intensity of the secondary image green-dominant pixels within the overlap area is equivalent to the average color intensity of the reference image green-dominant pixels within the overlap area;

selecting an initial seam line within the overlap area;

determining a position of an elevated feature in a small segment of the overlapping area from a digital elevation model; and

establishing the seam line within the overlap area, wherein the route of the seam line is altered based upon the position of an elevated feature.

16. The method of claim 16, further comprising a blending process for smoothing image transition within the overlap area.

17. The method of claim 17, wherein the blending process assigns a relative weight, determinative of inclusion in the output image, to the pixels of the secondary image.

18. The method of claim 18, wherein the relative weight ranges between zero, indicating no inclusion, and unity, indicating full inclusion.