Method and apparatus for coordinate system conversions

• US 6,766,343 B1
• Filed: 02/04/2000
• Issued: 07/20/2004
• Est. Priority Date: 02/04/2000
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Culp, Timothy R., Bell, David M., Maly, Dennis L.
• Primary Examiner(s): Ngo, Chuong Dinh
• Assistant Examiner(s): Do, Chat C
• Application Number:
  US09/499,061
• Time in Patent Office: 1,628 Days
• Field of Search: 708/100, 708/206, 708/422, 709/224, 707/1, 707/503, 707/2, 455/436, 345/419
• US Class Current: 708/442
• CPC Class Codes: G06T 3/00 Geometric image transformations in the plane of the image

Abstract

A method for converting between source coordinates in a source coordinate system and target coordinates in a target coordinate system includes the step of defining a coordinate system conversion tree extending from a root coordinate system and branching to a plurality of other coordinate-systems including the source and target coordinate systems so that the source and target coordinate systems are connected to a common coordinate system other than the root coordinate system. Coordinate conversions are performed between the source and target coordinates along branches extending from the source coordinate system to the common coordinate system and to the target coordinate system without returning to the root coordinate system. Contextual data is associated with the coordinates to permit conversion to an adjacent coordinate system. Since coordinate conversions are performed with respect to a common coordinate system, a distributed framework of coordinate systems is provided for reliably converting coordinates between source and target coordinate systems. New coordinate systems can be readily added to the tree.

Claims

1. A method for converting between source coordinates in a source coordinate system and target coordinates in a target coordinate system comprising the steps of:

defining a coordinate system conversion tree extending from a root coordinate system and branching to a plurality of other coordinate systems including the source and target coordinate systems so that the source and target coordinate systems are connected to a common coordinate system other than the root coordinate system, the root coordinate system is not being defined relative to another coordinate system so that it represents a root node in the conversion tree, and the common coordinate system is being defined relative to the root coordinate system; and

performing coordinate conversions between the source and target coordinates along branches extending from the source coordinate system to the common coordinate system and to the target coordinate system without returning to the root coordinate system.

2. A method according to claim 1 further comprising the step of associating contextual data with respective coordinates of each coordinate system for performing coordinate conversions with at least one adjacent coordinate system.

3. A method according to claim 2 wherein the step of associating contextual data comprises associating contextual data with respective coordinates of each coordinate system for performing coordinate conversion with only one adjacent coordinate system.

4. A method according to claim 1 wherein performing coordinate conversions comprises sequentially performing coordinate conversions up the coordinate system conversion tree from the source coordinate system to at least one adjacent coordinate system until a conversion is made with the common coordinate system.

5. A method according to claim 1 wherein performing coordinate conversions comprises sequentially performing coordinate conversions down the coordinate system conversion tree from the common coordinate system to at least one adjacent coordinate system until a conversion is made with the target coordinate system.

6. A method according to claim 1 further comprising the step of displaying an image of the converted coordinates in the target coordinate system.

7. A method according to claim 1 further comprising the steps of:

adding an additional coordinate system to the coordinate system conversion tree; and

verifying whether the additional coordinate system is connected to at least one other coordinate system via a common coordinate system, and performing conversions if the verifying is successful.

8. A method according to claim 7 further comprising the step of providing a warning if the step of verifying is unsuccessful.

9. A method according to claim 1 wherein each of the coordinate systems comprises a geospatial coordinate system.

10. A method according to claim 1 wherein each of the coordinate systems comprises an n-dimensional coordinate system.

11. A method for converting between source coordinates in a source coordinate system and target coordinates in a target coordinate system comprising the steps of:

defining a coordinate system conversion tree extending from a root coordinate system and branching to a plurality of other coordinate systems including the source and target coordinate systems so that the source and target coordinate systems are connected to a common coordinate system other than the root coordinate system with at least one intervening intermediate conversion system therebetween, the root coordinate system is not being defined relative to another coordinate system so that it represents a root node in the conversion tree, and the common coordinate system is being defined relative to the root coordinate system; and

performing coordinate conversions between the source and target coordinates along branches extending from the source coordinate system to the common coordinate system and to the target coordinate system without returning to the root coordinate system, the coordinates having contextual data associated therewith for each respective coordinate system for performing coordinate conversions with at least one adjacent coordinate system.

12. A method according to claim 11 wherein the coordinates have contextual data associated therewith for each respective coordinate system for performing coordinate conversion with only one adjacent coordinate system.

13. A method according to claim 11 wherein performing coordinate conversions comprises sequentially performing coordinate conversions up the portion of the coordinate system conversion tree from the source coordinate system to at least one adjacent coordinate system until a conversion is made with the common coordinate system.

14. A method according to claim 11 wherein performing coordinate conversions comprises sequentially performing coordinate conversions down the portion of the coordinate system conversion tree from the common coordinate system to at least one adjacent coordinate system until a conversion is made with the target coordinate system.

15. A method according to claim 11 further comprising the step of displaying an image of the converted coordinates in the target coordinate system.

16. A method according to claim 11 further comprising the steps of:

adding an additional coordinate system to the portion of the coordinate system conversion tree; and

verifying whether the additional coordinate system is connected to at least one other coordinate system via a common coordinate system, and performing conversions if the verifying is successful.

17. A method according to claim 16 further comprising the step of providing a warning if the step of verifying is unsuccessful.

18. A method according to claim 11 wherein each of the coordinate systems comprises a geospatial coordinate system.

19. A method according to claim 11 wherein each of the coordinate systems comprises an n-dimensional coordinate system.

20. A machine readable medium having machine readable instructions thereon for causing a computer to convert between source coordinates in a source coordinate system and target coordinates in a target coordinate system by performing the steps of:

defining a coordinate system conversion tree extending from a root coordinate system and branching to a plurality of other coordinate systems including the source and target coordinate systems so that the source and target coordinate systems are connected to a common coordinate system other than the root coordinate system with at least one intervening intermediate conversion system therebetween, the root coordinate system is not being defined relative to another coordinate system so that it represents a root node in the conversion tree, and the common coordinate system is being defined relative to the root coordinate system; and

performing coordinate conversions between the source and target coordinates along branches extending from the source coordinate system to the common coordinate system and to the target coordinate system without returning to the root coordinate system, the coordinates having contextual data associated therewith for each respective coordinate system for performing coordinate conversions with at least one adjacent coordinate system.

21. A machine readable medium according to claim 20 wherein the coordinates have contextual data associated therewith for each respective coordinate system for performing coordinate conversion with only one adjacent coordinate system.

22. A machine readable medium according to claim 20 wherein performing coordinate conversions comprises sequentially performing coordinate conversions up the portion of the coordinate system conversion tree from the source coordinate system to at least one adjacent coordinate system until a conversion is made with the common coordinate system.

23. A machine readable medium according to claim 20 wherein performing coordinate conversions comprises sequentially performing coordinate conversions down the portion of the coordinate system conversion tree from the common coordinate system to at least one adjacent coordinate system until a conversion is made with the target coordinate system.

24. A machine readable medium according to claim 20 further comprising the step of displaying an image of the converted coordinates in the target coordinate system.

25. A machine readable medium according to claim 20 further comprising the steps of:

adding an additional coordinate system to the portion of the coordinate system conversion tree; and

verifying whether the additional coordinate system is connected to at least one other coordinate system via a common coordinate system, and performing conversions if the verifying is successful.

26. A machine readable medium according to claim 25 further comprising the step of providing a warning if the step of verifying is unsuccessful.

27. A machine readable medium according to claim 20 wherein each of the coordinate systems comprises a geospatial coordinate system.

28. A machine readable medium according to claim 20 wherein each of the coordinate systems comprises an n-dimensional coordinate system.

29. An apparatus comprising:

a processor for converting image data at source coordinates in a source coordinate system to converted image data at target coordinates in a target coordinate system, said processor performing the steps of

defining a coordinate system conversion tree extending from a root coordinate system and branching to a plurality of other coordinate systems including the source and target coordinate systems so that the source and target coordinate systems are connected to a common coordinate system other than the root coordinate system with at least one intervening intermediate conversion system therebetween, the root coordinate system is not being defined relative to another coordinate system so that it represents a root node in the conversion tree, and the common coordinate system is being defined relative to the root coordinate system, and

performing coordinate conversions between the source and target coordinates along branches extending from the source coordinate system to the common coordinate system and to the target coordinate system without returning to the root coordinate system, the coordinates having contextual data associated therewith for each respective coordinate system for performing coordinate conversions with at least one adjacent coordinate system; and

a display connected to said processor for displaying converted image data in the target coordinate system.

30. An apparatus according to claim 29 wherein the coordinates have contextual data associated therewith for each respective coordinate system for performing coordinate conversion with only one adjacent coordinate system.

31. An apparatus according to claim 29 wherein performing coordinate conversions comprises sequentially performing coordinate conversions up the portion of the coordinate system conversion tree from the source coordinate system to at least one adjacent coordinate system until a conversion is made with the common coordinate system.

32. An apparatus according to claim 29 wherein performing coordinate conversions comprises sequentially performing coordinate conversions down the portion of the coordinate system conversion tree from the common coordinate system to at least one adjacent coordinate system until a conversion is made with the target coordinate system.

33. An apparatus according to claim 29 further comprising the steps of:

adding an additional coordinate system to the portion of the coordinate system conversion tree; and

verifying whether the additional coordinate system is connected to at least one other coordinate system via a common coordinate system, and performing conversions if the verifying is successful.

34. An apparatus according to claim 33 further comprising the step of providing a warning to said display if the step of verifying is unsuccessful.

35. An apparatus according to claim 29 wherein each of the coordinate systems comprises a geospatial coordinate system.

36. An apparatus according to claim 29 wherein each of the coordinate systems comprises an n-dimensional coordinate system.