Tiled projections for planar processing of round earth data

• US 8,638,327 B2
• Filed: 05/08/2008
• Issued: 01/28/2014
• Est. Priority Date: 11/14/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kallay, Michael, Kunen, Isaac Kenneth
• Primary Examiner(s): Xiao, Ke
• Assistant Examiner(s): Imperial, Jed-Justin
• Application Number:
  US12/117,572
• Publication Number:
  US 20090123088A1
• Time in Patent Office: 2,091 Days
• Field of Search: 345/418, 345/419, 345/423, 345582-588, 382276-308
• US Class Current: 345/418
• CPC Class Codes: G06T 3/12 Panospheric to cylindrical image transformations

Abstract

A system and method that facilitates planar processing of round earth data by employing a tiled projection is provided. The tiled projection is a two-step projection from the surface of the earth to a common plane that preserves polygons and polygonal paths. During the first step, the system performs a gnomonic projection to the facets of a circumscribed platonic solid, which maps spherical polygons to spatial polygons on the facets of the solid. During the second step, the system performs a polygon-preserving projection from the facets of the platonic solid to tiles in common plane. Thus, projections from multiple facets of the platonic solid on the common plane are processed by employing a planar algorithm.

Claims

1. A computer implemented system configured to facilitate tiled projections for planar processing of spherical data, the computer implemented system comprising:

a processor;

a mapping component configured to project the spherical data, mapped onto facets of a polyhedron, to a single plane while preserving at least one of polygons or polygonal paths via insertion of at least one fake crease vertex;

a processing component configured to employ a planar algorithm to compute query results from data mapped to the single plane, wherein the processing component is further configured to display a planar processing result of the planar algorithm on a sphere corresponding to the spherical data; and

a computer-readable storage medium storing instructions that, when executed by the processor, cause the processor to implement at least one of the mapping component or the processing component.

2. The computer implemented system of claim 1, wherein the polyhedron is at least one of an octahedron, a tetrahedron or a cube, the polyhedron providing circumscription of a sphere associated with the spherical data.

3. The computer implemented system of claim 1, wherein the mapping component is configured to project at least one of an entire hemisphere or an entire sphere onto the single plane based in part on the polyhedron employed for the mapping, such that polygons and polygonal paths are preserved during the mapping.

4. The computer implemented system of claim 1, further comprising a first projection component configured to map one or more points on a sphere to one or more points on corresponding facets of the polyhedron by employing a gnomonic projection.

5. The computer implemented system of claim 4, further comprising a second projection component configured to map the one or more points on the corresponding facets to one or more points on corresponding tiles of the single plane by employing a central projection.

6. The computer implemented system of claim 1, further comprising a crease vertex addition component configured to insert the fake crease vertex on a projection in the single plane at a crease that separates the projection onto two tiles.

7. The computer implemented system of claim 1, further comprising a node vertex addition component configured to insert a fake node vertex on a projection in the single plane at a seam that separates the projection onto two planes.

8. The computer implemented system of claim 1, further comprising, an inverse mapping component configured to perform a polygon-preserving inverse mapping to map a result of the computation from the single plane to spherical coordinates.

9. The computer implemented system of claim 1, further comprising a polyhedron selection component configured to determine a type of polyhedron employed for the mapping based in part on at least one of a user input or an artificial intelligence(AI)-based scheme.

10. A computer implemented method that facilitates mapping of data from a surface of a sphere to a common plane, the computer implemented method comprising:

executing by a processor, instructions that, when executed, cause operations to be performed comprising;

generating a projection by projecting data mapped to facets of a polyhedron onto the common plane;

preserving a polygon of the polyhedron on the projection via insertion of a fake crease vertex;

performing at least one query operation on the projection by employing a planar algorithm, the at least one query operation comprising computing query results from data projected onto the common plane; and

projecting a planar processing result of the planar algorithm onto the surface of the sphere.

11. The computer implemented method of claim 10, wherein the polyhedron is at least one of an octahedron, a tetrahedron or a cube that circumscribes the sphere.

12. The computer implemented method of claim 10, further comprising inserting the at least one fake crease vertex on the projection at a crease that separates the projection onto two tiles in the common plane.

13. The computer implemented method of claim 10, further comprising employing a gnomonic projection to map at least one point from the surface of the sphere to at least one point on one or more corresponding facets of the polyhedron.

14. The computer implemented method of claim 13, further comprising employing a central projection to map the at least one point on the one or more corresponding facets to at least one point on one or more corresponding tiles in the common plane.

15. The computer implemented method of claim 10, further comprising projecting at least one of an entire hemisphere or the entire sphere onto a single plane based in part on the polyhedron employed for mapping.

16. A computer-readable storage medium having computer executable instructions that, when executed by a processor, cause operations to be performed, comprising:

generating a projection by projecting spherical data mapped to facets of a polyhedron onto a common plane;

preserving a polygon of the polyhedron on the projection via insertion of a fake crease vertex;

processing data projected onto the common plane by employing a planar algorithm to perform at least one query operation, the at least one query operation comprising computing query results from the projection; and

projecting a planar processing result of the planar algorithm onto a sphere corresponding to the spherical data.

17. The computer readable storage medium of claim 16, wherein the polyhedron is at least one of an octahedron, a tetrahedron or a cube that circumscribes a sphere.

18. The computer readable storage medium of claim 16, wherein the projection onto the common plane is at least one of an affine projection or a central projection.

19. The computer readable storage medium of claim 16, further comprising, mapping an arc on a sphere as a straight line in the common plane, when a projection of the arc on the common plane is contained in one tile.

20. The computer readable storage medium of claim 16, further comprising, mapping an arc on the sphere as a broken straight line by inserting the at least one fake crease vertex, when a projection of the arc on the common plane is contained in two or more tiles.