System and method for authentication of a workpiece using three dimensional shape recovery
First Claim
1. Apparatus for use in generating a string for use in determining whether a workpiece is valid, comprising:
- an electromagnetic radiation source for illuminating at least one portion of the workpiece with electromagnetic radiation from one or more illumination positions relative to said at least one portion;
an imaging device for generating one or more images of optical characteristics of the at least one portion when the at least one portion is illuminated with the radiation by the source from respective illumination positions; and
a string generator that generates the string based upon, at least in part, recovered shapes of 3-D features of the illuminated surface of the at least one portion, the generator recovering the shapes from the one or more images.
9 Assignments
0 Petitions
Accused Products
Abstract
A workpiece authentication system uses shape recovery techniques to extract explicit three dimensional (“3-D”) features of the surface geometry of the designated portion of a workpiece from images produced using different lighting conditions. The system then bases authentication on the 3-D surface features. The system recovers surface normals, or equivalently gradients, for selected locations within a designated portion of the workpiece from multiple enrollment images produced under different illumination conditions. The system then encodes the surface normal information into authentication indicia that is placed on the workpiece and/or stores the surface normals or related information. Thereafter, the system determines that a given workpiece is authentic if the surface normals recovered from various verification images correspond to the stored surface normal information or the surface normal information encoded into the indicia. Alternatively, the system may use the surface normals to predict what an image should contain when the workpiece is subjected to a particular lighting condition. The system then determines that the workpiece is authentic if the predicted image and the image produced using the workpiece correspond. The system may instead encode brightness patterns associated with one or more enrollment images into the indicia. The system then recovers surface normals from images produced during verification operations, predicts what the brightness image should contain and compares the enrollment image to the prediction.
74 Citations
62 Claims
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1. Apparatus for use in generating a string for use in determining whether a workpiece is valid, comprising:
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an electromagnetic radiation source for illuminating at least one portion of the workpiece with electromagnetic radiation from one or more illumination positions relative to said at least one portion; an imaging device for generating one or more images of optical characteristics of the at least one portion when the at least one portion is illuminated with the radiation by the source from respective illumination positions; and a string generator that generates the string based upon, at least in part, recovered shapes of 3-D features of the illuminated surface of the at least one portion, the generator recovering the shapes from the one or more images. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. Method for generating a string for use in determining whether a workpiece is valid, comprising:
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illuminating at least one portion of the workpiece with electromagnetic radiation from one or more illumination positions relative to the at least one portion; generating one or more images of optical characteristics of 3-D features of a surface of the at least one portion when the at least one portion is illuminated with the radiation at the one or more illumination positions; recovering the shapes of one or more of the 3-D features from the one or more images; and generating the string based upon, at least in part, the recovered one or more shapes. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. Computer-readable memory comprising computer-executable program instructions for use in generating a string for use in determining whether a workpiece is valid, the instructions when executed causing:
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illumination of at least one portion of the workpiece with electromagnetic radiation from one or more illumination positions relative to said at least one portion; generation of one or more images of optical characteristics of 3-D features of a surface of the at least one portion when the at least one portion is illuminated with the radiation at the one or more illumination positions; recovery of the shapes of one or more of the 3-D features from the one or more images; and generation of the string based upon, at least in part, the one or more shapes recovered from the one or more images. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A method for authenticating a workpiece
illuminating at least one portion of the workpiece from a plurality of illumination positions; -
producing one or more images of the optical characteristics of 3-D features of the surface of the at least one portion; recovering from the one or more images the respective shapes of one or more of the 3-D features; generating a string based upon, at least in part, the shapes recovered from the one or more images; and determining if the string corresponds to a previously generated string that is associated with the workpiece.
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55. A method for authenticating a workpiece
illuminating at least one portion of the workpiece from a plurality of illumination positions and producing one or more image of the optical characteristics of 3-D features of the surface of the at least one portion; -
recovering from the one or more images the respective shapes of one or more of the 3-D features; predicting an image produced under a different illumination condition based on the recovered shapes; determining that the workpiece is authentic if the predicted image corresponds to an image produced during workpiece enrollment using the different illumination condition.
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56. Method for generating a string for use in determining whether a workpiece is valid
illuminating at least one portion of the workpiece with electromagnetic radiation from a plurality of illumination positions relative to said at least one portion; -
generating one or more images of optical characteristics of 3-D features of the at least one portion when the at least one portion is illuminated with the radiation at the respective illumination positions; recovering from the one or more images surface normals or gradients that correspond to selected ones of the 3-D features; and generating a string based upon, at least in part, the surface normals and information that identifies one or both of the workpiece and an associated product or document. - View Dependent Claims (57)
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58. Method for authenticating a workpiece
illuminating at least one portion of the workpiece with electromagnetic radiation from a plurality of illumination positions relative to said at least one portion; -
generating one or more images of optical characteristics of 3-D features of the at least one portion when the at least one portion is illuminated with the radiation at the respective illumination positions; recovering from the one or more images surface normals or gradients that correspond to selected ones of the 3-D features; generating a string based upon, at least in part, the surface normals and information that identifies one or both of the workpiece and an associated product or document; and determining that the workpiece is authentic if the generated string corresponds to a string associated with the workpiece. - View Dependent Claims (59)
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60. Method for authenticating a workpiece
illuminating at least one portion of the workpiece with electromagnetic radiation from a plurality of illumination positions relative to said at least one portion; -
generating one or more images of optical characteristics of 3-D features of the at least one portion when the at least one portion is illuminated with the radiation at the respective illumination positions; recovering from the one or more images surface normals or gradients that correspond to selected ones of the 3-D features; predicting an image that corresponds to a predetermined illumination condition based on the recovered surface normals or gradients; and determining if the predicted image corresponds to an image associated with the workpiece.
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61. Method for identifying a workpiece
illuminating at least one portion of the workpiece with electromagnetic radiation from a plurality of illumination positions relative to said at least one portion; -
generating one or more images of optical characteristics of 3-D features of the at least one portion when the at least one portion is illuminated with the radiation at the respective illumination positions; recovering from the one or more images surface normals or gradients that correspond to selected ones of the 3-D features; generating a string based upon, at least in part, the surface normals; and identifying the workpiece based on a correspondence between the generated string and a stored string that is associated with the workpiece.
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62. Method for authenticating a workpiece
illuminating at least one portion of the workpiece with electromagnetic radiation from a plurality of illumination positions relative to said at least one portion; -
generating one or more images of optical characteristics of 3-D features of the at least one portion when the at least one portion is illuminated with the radiation at the respective illumination positions; recovering from the one or more images surface normals or gradients that correspond to selected ones of the 3-D features; generating a string based upon, at least in part, the surface normals and information that identifies one or both of the workpiece and an associated product or document; determining that the workpiece is authentic if the generated string corresponds to a string associated with the workpiece; if the generated string does not correspond to the string associated with the workpiece determining if the workpiece is within a predetermined range of position and orientation to an enrollment orientation associated with the workpiece; if the workpiece is not generating a new string with the workpiece is within the predetermined range and if the new string corresponds to the string associated with the workpiece determining that the workpiece is authentic; and if the generated string and the string associated with the workpiece do not correspond when the workpiece is within the predetermined range, determining that the workpiece is counterfeit.
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Specification