초록 ▼

A plate solving methodology determines celestial coordinates of an image. Star locations are extracted from the image in terms of pixel coordinates. A group of four stars, referred to as a “test quad”, is identified. A signature for the test quad is generated. In one embodiment, this test signature

A plate solving methodology determines celestial coordinates of an image. Star locations are extracted from the image in terms of pixel coordinates. A group of four stars, referred to as a “test quad”, is identified. A signature for the test quad is generated. In one embodiment, this test signature is derived by determining the separations of the four stars in the test quad, normalized by the largest separation. In one embodiment, the signature also includes the sum of these normalized separations. A query is performed, using the generated signature, against a database of reference signatures for known groups of stars (referred to as “reference quads”). A geometric transform is determined, establishing the relationship between the test quad and a reference quad that matches within a specified tolerance. This geometric transform defines the celestial coordinates of the image. Additional verification steps can be performed to confirm the accuracy of the match.

대표청구항 ▼

1. A computer-implemented method for determining celestial coordinates corresponding to an image, comprising: receiving an image comprising a plurality of depicted objects;generating, at a processor, a list of initial coordinates indicating positions, with respect to an origin point for the image, o

1. A computer-implemented method for determining celestial coordinates corresponding to an image, comprising: receiving an image comprising a plurality of depicted objects;generating, at a processor, a list of initial coordinates indicating positions, with respect to an origin point for the image, of a plurality of depicted objects in the image;selecting, at the processor, a group of objects from the plurality of depicted objects;generating, at the processor, a test signature based on the initial coordinates of the objects in the selected group;searching a data store for at least one reference signature that matches the generated test signature within a specified tolerance;for at least one reference signature that matches the generated test signature within a specified tolerance: obtaining a celestial position corresponding to the reference signature;determining, from the obtained celestial position corresponding to the reference signature, celestial coordinates for the image; andoutputting the determined celestial coordinates at an output device;wherein searching a data store for at least one reference signature that matches the generated test signature within a specified tolerance comprises:for at least a plurality of reference signatures in the data store, performing an affine fit operation to generate a geometric transform representing the relationship between the generated test signature and the reference signature; andidentifying at least one reference signature for which the generated geometric transform indicates that the reference signature matches the generated test signature within a specified tolerance. 2. The method of claim 1, wherein the image comprises at least one selected from the group consisting of: a digital image received via a network connection;a digital image obtained from a storage device;a digital image obtained from an optical sensing device;an image received from a telescope; anda photographic image. 3. The method of claim 1, wherein the depicted objects comprise representations of celestial objects. 4. The method of claim 1, wherein the depicted objects comprise representations of stars. 5. The method of claim 1, wherein the initial coordinates comprise pixel-based locations of depicted objects. 6. The method of claim 1, wherein selecting a group of objects comprises selecting a group of four objects. 7. The method of claim 1, wherein generating a test signature comprises generating a test signature based on separation among pairs of depicted objects in the selected group. 8. The method of claim 1, wherein generating a test signature comprises generating a test signature comprising normalized representations of separation among pairs of depicted objects in the selected group. 9. The method of claim 1, wherein generating a test signature comprises: for each pair of depicted objects in the selected group, determining a separation between the depicted objects;sorting the determined separations;normalizing the determined separations with respect to the largest determined separation; andassembling a signature comprising the normalized separations. 10. The method of claim 1, wherein each reference signature in the data store corresponds to a group of celestial objects. 11. The method of claim 1, further comprising, prior to outputting the determined celestial coordinates, verifying a match between the generated test signature and a reference signature that matches the generated test signature within a specified tolerance. 12. The method of claim 11, wherein verifying a match between the generated test signature and a reference signature that matches the generated test signature within a specified tolerance comprises: determining at least one of a skew criterion and a stretch criterion for the generated test signature with respect to the reference signature;determining whether the determined at least one of a skew criterion and a stretch criterion falls within a predefined tolerance for verifying a match. 13. The method of claim 11, wherein verifying a match between the generated test signature and a reference signature that matches the generated test signature within a specified tolerance comprises: determining a transform defining a relationship between the group of objects corresponding to the test signature and a group of celestial objects corresponding to the reference signature;obtaining, from a data store, a position of an additional celestial object;applying the transform to the obtained position of the additional celestial object to obtain an expected position of the additional celestial object within the image;determining whether a depiction of the additional celestial object appears within the image at a position within a tolerance range of the expected position. 14. The method of claim 11, further comprising, responsive to a failure to verify the match, repeating the steps of selecting a group of objects, generating a test signature, searching a data store for a reference signature that matches the generated test signature within a specified tolerance, and verifying the match. 15. The method of claim 1, wherein: the reference signature that matches the generated test signature within a specified tolerance corresponds to a group of celestial objects; andthe obtained celestial position corresponding to the reference signature comprises a celestial position for the group of celestial objects;and wherein determining, from the obtained celestial position corresponding to the reference signature, celestial coordinates for the image, comprises determining a transform defining a relationship between the group of objects corresponding to the test signature and the group of celestial objects. 16. The method of claim 1, wherein receiving an image comprises receiving an image free of information describing the celestial position of the image. 17. The method of claim 1, wherein outputting the determined celestial coordinates at an output device comprises outputting the determined celestial coordinates in terms of right ascension and declination. 18. A computer-implemented method for determining celestial coordinates corresponding to an image, comprising: receiving an image comprising a plurality of depicted objects;generating, at a processor, a list of initial coordinates indicating positions, with respect to an origin point for the image, of a plurality of depicted objects in the image;selecting, at the processor, a group of objects from the plurality of depicted objects;generating, at the processor, a test signature based on the initial coordinates of the objects in the selected group;searching a data store for at least one reference signature that matches the generated test signature within a specified tolerance;for at least one reference signature that matches the generated test signature within a specified tolerance: obtaining a celestial position corresponding to the reference signature;determining, from the obtained celestial position corresponding to the reference signature, celestial coordinates for the image; andoutputting the determined celestial coordinates at an output devicewherein generating a test signature comprises:for each pair of depicted objects in the selected group, determining a separation between the depicted objects;sorting the determined separations;normalizing the determined separations with respect to the largest determined separation; andassembling a signature comprising the normalized separations and the sum of the normalized signatures. 19. A system for determining celestial coordinates corresponding to an image, comprising: an image capture device, configured to capture an image comprising a plurality of depicted objects;a plate list generator, configured to generate a list of initial coordinates indicating positions, with respect to an origin point for the image, of a plurality of depicted objects in the image;a signature generator, configured to select a group of objects from the plurality of depicted objects and for generating a test signature based on the initial coordinates of the objects in the selected group;a search module, configured to search a data store for at least one reference signature that matches the generated test signature within a specified tolerance;a processor, configured to, for at least one reference signature that matches the generated test signature within a specified tolerance: obtain a celestial position corresponding to the reference signature; anddetermine, from the obtained celestial position corresponding to the reference signature, celestial coordinates for the image; andan output device, configured to output the determined celestial coordinates;wherein the search module is configured to search a data store for at least one reference signature that matches the generated test signature within a specified tolerance by:for at least a plurality of reference signatures in the data store, performing an affine fit operation to generate a geometric transform representing the relationship between the generated test signature and the reference signature; andidentifying at least one reference signature for which the generated geometric transform indicates that the reference signature matches the generated test signature within a specified tolerance. 20. The system of claim 19, wherein the image comprises at least one selected from the group consisting of: a digital image received via a network connection;a digital image obtained from a storage device;a digital image obtained from an optical sensing device;an image received from a telescope; anda photographic image. 21. The system of claim 19, wherein the depicted objects comprise representations of celestial objects. 22. The system of claim 19, wherein the initial coordinates comprise pixel-based locations of depicted objects. 23. The system of claim 19, wherein the signature generator is configured to select a group of four objects. 24. The system of claim 19, wherein the signature generator is configured to generate the test signature based on separation among pairs of depicted objects in the selected group. 25. The system of claim 19, wherein the signature generator is configured to generate a test signature by: for each pair of depicted objects in the selected group, determining a separation between the depicted objects;sorting the determined separations;normalizing the determined separations with respect to the largest determined separation; andassembling a signature comprising the normalized separations. 26. The system of claim 19, wherein each reference signature in the data store corresponds to a group of celestial objects. 27. The system of claim 19, wherein the processor is configured to verify a match between the generated test signature and a reference signature that matches the generated test signature within a specified tolerance. 28. The system of claim 27, wherein the processor is configured to verify a match between the generated test signature and a reference signature that matches the generated test signature within a specified tolerance by: determining at least one of a skew criterion and a stretch criterion for the generated test signature with respect to the reference signature;determining whether the determined at least one of a skew criterion and a stretch criterion falls within a predefined tolerance for verifying a match. 29. The system of claim 27, wherein the processor is configured to verify a match between the generated test signature and a reference signature that matches the generated test signature within a specified tolerance by: determining a transform defining a relationship between the group of objects corresponding to the test signature and a group of celestial objects corresponding to the reference signature;obtaining, from a data store, a position of an additional celestial object;applying the transform to the obtained position of the additional celestial object to obtain an expected position of the additional celestial object within the image;determining whether a depiction of the additional celestial object appears within the image at a position within a tolerance range of the expected position. 30. The system of claim 27, wherein, responsive to a failure to verify the match, the signature generator is configured to repeat the step of selecting a group of objects and generating a test signature, and the search module is configured to repeat the step of searching a data store for a reference signature that matches the generated test signature within a specified tolerance, and the processor is configured to repeat the step of verifying the match. 31. The system of claim 19, wherein: the reference signature that matches the generated test signature within a specified tolerance corresponds to a group of celestial objects; andthe obtained celestial position corresponding to the reference signature comprises a celestial position for the group of celestial objects;and wherein the processor is configured to determine celestial coordinates for the image by determining a transform defining a relationship between the group of objects corresponding to the test signature and the group of celestial objects. 32. The system of claim 19, wherein the captured image is free of information describing the celestial position of the image. 33. The system of claim 19, wherein the output device is configured to output the determined celestial coordinates by outputting the determined celestial coordinates in terms of right ascension and declination. 34. A system for determining celestial coordinates corresponding to an image, comprising: an image capture device, configured to capture an image comprising a plurality of depicted objects;a plate list generator, configured to generate a list of initial coordinates indicating positions, with respect to an origin point for the image, of a plurality of depicted objects in the image;a signature generator, configured to select a group of objects from the plurality of depicted objects and for generating a test signature based on the initial coordinates of the objects in the selected group;a search module, configured to search a data store for at least one reference signature that matches the generated test signature within a specified tolerance;a processor, configured to, for at least one reference signature that matches the generated test signature within a specified tolerance: obtain a celestial position corresponding to the reference signature; anddetermine, from the obtained celestial position corresponding to the reference signature, celestial coordinates for the image; andan output device, configured to output the determined celestial coordinates;wherein the signature generator is configured to generate a test signature by:for each pair of depicted objects in the selected group, determining a separation between the depicted objects;sorting the determined separations;normalizing the determined separations with respect to the largest determined separation; andassembling a signature comprising the normalized signatures and the sum of the normalized signatures. 35. A computer program product for determining celestial coordinates corresponding to an image, comprising: a non-transitory computer-readable storage medium; andcomputer program code, encoded on the medium, configured to cause at least one processor to perform the steps of: receiving an image comprising a plurality of depicted objects;generating, at a processor, a list of initial coordinates indicating positions, with respect to an origin point for the image, of a plurality of depicted objects in the image;selecting, at the processor, a group of objects from the plurality of depicted objects;generating, at the processor, a test signature based on the initial coordinates of the objects in the selected group;searching a data store for at least one reference signature that matches the generated test signature within a specified tolerance;for at least one reference signature that matches the generated test signature within a specified tolerance: obtaining a celestial position corresponding to the reference signature;determining, from the obtained celestial position corresponding to the reference signature, celestial coordinates for the image; andoutputting the determined celestial coordinates at an output device;wherein the computer program code configured to cause at least one processor to search a data store for at least one reference signature that matches the generated test signature within a specified tolerance comprises computer program code configured to cause at least one processor to perform the steps of:for at least a plurality of reference signatures in the data store, performing an affine fit operation to generate a geometric transform representing the relationship between the generated test signature and the reference signature; andidentifying at least one reference signature for which the generated geometric transform indicates that the reference signature matches the generated test signature within a specified tolerance.