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US 2015/0029561 A1Published application
Skew angle determination
AssigneeAuthentix, Inc.
InventorsJoseph Paulter, Alan Hunt, Ralph Payne
Life of this patent
Estimating the term…
Abstract
The skew angle of a document image is determined or estimated. The skew angle is determined or estimated by examining patterns found within a Fast Fourier Transform of a subset of the document image. This technique exploits the internal structure of the document designs to allow fast and accurate skew angle estimation, including for arbitrary document fragments.
Claims27
A method for determining a skew angle of an image of a document, the method comprising:
- receiving image data representing the image of the document into an electronic memory;
- after receiving the image data, performing a windowing function on the image data to produce windowed image data;
- performing a Fourier Transform on the windowed image data to produce transformed image data;
- performing a radial line integration of the transformed image data to produce integrated image data;
- determining a peak value from the integrated image data to determine the skew angle;
- and
- providing an output electronic signal that is indicative of the determined skew angle.
4 more elements
(canceled)
10-12. (canceled)
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A system for determining a skew angle of an image of an object, the system comprising:
- circuitry configured for receiving image data representing the image of the object;
- circuitry configured for performing a windowing function on the image data to produce windowed image data;
- circuitry configured for performing a Fourier Transform on the windowed image data to produce transformed image data;
- circuitry configured for performing a radial line integration of the transformed image data to produce integrated image data;
- and
- circuitry configured for determining a peak value from the integrated image data to determine the skew angle.
3 more elements
26-27. (canceled)
Dependencies are inferred from the claim text.