Method and apparatus for encoding paper with information
First Claim
Patent Images
1. A method of determining a transformation of a paper document including:
- optically scanning the paper document to generate scan data;
transforming the scan data to a frequency domain;
identifying frequency components in the transformed scan data corresponding to texture resulting from the paper'"'"'s manufacture; and
determining from said frequency components one or more possible transformations of the scanned documents from a reference state.
6 Assignments
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Accused Products
Abstract
Paper is textured with a pattern that yields a known signature signal when transformed to the frequency domain. This signature can be used for various purposes, including determining the angular orientation of the paper when scanned, conveying a plural-bit digital watermark, and for simple document recognition purposes (e.g., photocopiers that refuse to reproduce banknotes). The texturing can be effected during the paper-making process, e.g., by shaping the surface of a de-watering element accordingly.
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Citations
12 Claims
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1. A method of determining a transformation of a paper document including:
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optically scanning the paper document to generate scan data;
transforming the scan data to a frequency domain;
identifying frequency components in the transformed scan data corresponding to texture resulting from the paper'"'"'s manufacture; and
determining from said frequency components one or more possible transformations of the scanned documents from a reference state. - View Dependent Claims (2, 3, 4, 5)
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6. A method including:
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optically scanning a paper document to generate scan data;
transforming the scan data to a frequency domain;
identifying frequency components in the transformed scan data corresponding to texture resulting from the paper'"'"'s manufacture; and
interpreting said identified frequency components to yield payload data including at least a registration indicator. - View Dependent Claims (7, 8, 9, 10)
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11. A paper-making process including:
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defining a frequency-domain signal, wherein the frequency-domain signal comprises an orientation component;
inverse transforming the frequency-domain signal to yield a two-dimensional pattern in the spatial domain;
shaping an element of the paper-making apparatus in accordance with said spatial domain pattern; and
imparting said pattern to a paper surface, wherein the orientation component provides an orientation reference for paper made according to said paper-making process. - View Dependent Claims (12)
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Specification