Generating a composite field of view using a plurality of oblique panoramic images of a geographic area

• US 9,219,858 B2
• Filed: 08/17/2013
• Issued: 12/22/2015
• Est. Priority Date: 06/10/2013
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Fan, Quanfu, Miyazawa, Sachiko, Pankanti, Sharathchandra
• Primary Examiner(s): Thompson, James A
• Application Number:
  US13/969,536
• Publication Number:
  US 20140362174A1
• Time in Patent Office: 857 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

Generating a composite geo-referenced panoramic field of view image of a geographic area is provided. Geodetic coordinates are generated for each of a plurality of pixels in a digital image capturing the geographic area based on a corrected amount of image distortion in each line of pixels in the plurality of pixels in the digital image. Each of the plurality of pixels in the digital image with the calculated geodetic coordinates is mapped to a geo-referenced map corresponding to the geographic area based on the calculated geodetic coordinates of each pixel. The composite geo-referenced panoramic field of view image of the geographic area is generated based on the mapping of each of the plurality of pixels in the digital image with the calculated geodetic coordinates to the geo-referenced map corresponding to the geographic area captured in the digital image.

Claims

1. A computer system for generating a composite geo-referenced panoramic field of view image of a geographic area, the computer system comprising:

a bus system;

a storage device connected to the bus system, wherein the storage device stores computer readable program code; and

a processor unit connected to the bus system, wherein the processor unit executes the computer readable program code to identify solid angle vectors projecting from a center of Earth along a geographic coordinate system line corresponding to a line of pixels in a digital image capturing the geographic area with known geodetic coordinates associated with a selected set of reference coordinates to form a plurality of solid angles;

calculate a distance between a vertical axis and each of the solid angle vectors along the geographic coordinate system line corresponding to the line of pixels in the digital image using a non-linear geographical distance formula;

calculate geodetic coordinates of each of a plurality of pixels in the digital image capturing the geographic area based on a corrected amount of image distortion in each line of pixels in the plurality of pixels in the digital image;

map each of the plurality of pixels in the digital image with the calculated geodetic coordinates to a geo-referenced map corresponding to the geographic area based on the calculated geodetic coordinates of each pixel; and

generate the composite geo-referenced panoramic field of view image of the geographic area based on the mapping of each of the plurality of pixels in the digital image with the calculated geodetic coordinates to the geo-referenced map corresponding to the geographic area captured in the digital image.

2. The computer system of claim 1, wherein the processor unit executes the computer readable program code to receive an image file that includes a header and the digital image of the geographic area captured at an oblique angle by an imaging device located on a mobile aerial platform.

3. The computer system of claim 2, wherein the processor unit executes the computer readable program code to select the set of reference coordinates from one or more sets of reference coordinates included in data of the header of the image file.

4. The computer system of claim 2, wherein the processor unit executes the computer readable program code to identify depression angle vectors projecting from a known location associated with the imaging device along the geographic coordinate system line corresponding to the line of pixels in the digital image with known geodetic coordinates associated with the selected set of reference coordinates to form a plurality of depression angles.

5. The computer system of claim 4, wherein the processor unit executes the computer readable program code to measure an amount of image distortion between the plurality of solid angles and the plurality of depression angles based on the calculated distance between the vertical axis and each of the solid angle vectors along the geographic coordinate system line corresponding to the line of pixels in the digital image.

6. The computer system of claim 5, wherein the processor unit executes the computer readable program code to calculate an image distortion scaling factor based on the measured amount of image distortion between the plurality of solid angles and the plurality of depression angles;

and use the calculated image distortion scaling factor to correct the measured amount of image distortion in the line of pixels in the digital image caused by an ellipsoidal geometry of the earth and the oblique angle of the digital image.

7. The computer system of claim 2, wherein the processor unit executes the computer readable program code to calculate an amount of optical distortion of pixels in the digital image caused by the imaging device based on imaging device data included in a sub header of the image file.

8. The computer system of claim 2, wherein the processor unit executes the computer readable program code to retrieve an elevation of the imaging device when the digital image was captured from the header of the image file;

and adjust the elevation of the imaging device when the digital image was captured by subtracting an elevation of a center of the geographic area captured in the digital image.

9. A computer program product stored on a computer readable storage medium having computer readable program code encoded thereon that is executable by a computer for generating a composite geo-referenced panoramic field of view image of a geographic area, the computer program product comprising:

computer readable program code for identifying solid angle vectors projecting from a center of Earth along a geographic coordinate system line corresponding to a line of pixels in a digital image capturing the geographic area with known geodetic coordinates associated with a selected set of reference coordinates to form a plurality of solid angles;

computer readable program code for calculating a distance between a vertical axis and each of the solid angle vectors along the geographic coordinate system line corresponding to the line of pixels in the digital image using a non-linear geographical distance formula;

computer readable program code for calculating geodetic coordinates of each of a plurality of pixels in the digital image capturing the geographic area based on a corrected amount of image distortion in each line of pixels in the plurality of pixels in the digital image;

computer readable program code for mapping each of the plurality of pixels in the digital image with the calculated geodetic coordinates to a geo-referenced map corresponding to the geographic area based on the calculated geodetic coordinates of each pixel; and

computer readable program code for generating the composite geo-referenced panoramic field of view image of the geographic area based on the mapping of each of the plurality of pixels in the digital image with the calculated geodetic coordinates to the geo-referenced map corresponding to the geographic area captured in the digital image.

10. The computer program product of claim 9, further comprising:

computer readable program code for receiving an image file that includes a header and the digital image of the geographic area captured at an oblique angle by an imaging device located on a mobile aerial platform.

11. The computer program product of claim 10, further comprising:

computer readable program code for selecting the set of reference coordinates from one or more sets of reference coordinates included in data of the header of the image file.

12. The computer program product of claim 10, further comprising:

computer readable program code for identifying depression angle vectors projecting from a known location associated with the imaging device along the geographic coordinate system line corresponding to the line of pixels in the digital image with known geodetic coordinates associated with the selected set of reference coordinates to form a plurality of depression angles.

13. The computer program product of claim 12, further comprising:

computer readable program code for measuring an amount of image distortion between the plurality of sold angles and the plurality of depression angles based on the calculated distance between the vertical axis and each of the solid angle vectors along the geographic coordinate system line corresponding to the line of pixels in the digital image.

14. The computer program product of claim 13, further comprising:

computer readable program code for calculating the image distortion scaling factor based on a measured amount of image distortion between the plurality of solid angles and the plurality of depression angles; and

computer readable program code for using the calculated image distortion scaling factor to correct the measured amount of image distortion in the line of pixels in the digital image caused by an ellipsoidal geometry of the earth and the oblique angle of the digital image.

15. The computer program product of claim 10, further comprising:

computer readable program code for calculating an amount of optical distortion of pixels in the digital image caused by the imaging device based on imaging device data included in a sub header of the image file.

16. The computer program product of claim 10, further comprising:

computer readable program code for retrieving an elevation of the imaging device when the digital image was captured from the header of the image file; and

computer readable program code for adjusting the elevation of the imaging device when the digital image was captured by subtracting an elevation of a center of the geographic area captured in the digital image.

17. The computer program product of claim 9, further comprising:

computer readable program code for selecting an object in the digital image of the geographic area.

18. The computer program product of claim 17, further comprising:

computer readable program code for performing geodetic mapping of the selected object in the digital image to a position on a geo-referenced map using a calculated image distortion scaling factor associated with the digital image; and

computer readable program code for calculating the position on the geo-referenced map corresponding to the selected object in the digital image based on the performed geodetic mapping.