Document processing methods
AssigneeDigimarc Corporation
InventorsGeoffrey B. Rhoads, Tony F. Rodriguez
Life of this patent
Estimating the term…
Abstract
Directional albedo of a particular article, such as an identity card, is measured and stored. When the article is later presented, it can be confirmed to be the same particular article by re-measuring the albedo function, and checking for correspondence against the earlier-stored data. The re-measuring can be performed through us of a handheld optical device, such as a camera-equipped cell phone. The albedo function can serve as random key data in a variety of cryptographic applications. The function can be changed during the life of the article. A variety of other features are also detailed.
Claims21
A method comprising:
- receiving a card, the card having a set of plural physical features that, in the aggregate, define an initial state;
- applying a stimulus to the card, said stimulus causing plural of said physical features to change, thereby defining a second state of said set of features;
- and
- storing data related to said second state;
- wherein said sets of physical features comprise sets of directional albedo features.
A method of customizing a card comprising:
- applying laser irradiation to first regions of said card from a first direction;
- and
- applying laser irradiation to second regions of said card from a second, different, direction;
- wherein said applying of laser irradiation causes directional albedo parameters of the card to change.
A method comprising:
- receiving a card from an individual owner thereof;
- applying a first stimulus to the card to change physical attributes thereof from an initial state to an intermediate state;
- applying a second, different stimulus to the card to change physical attributes thereof from the intermediate state to an ending state;
- and
- storing data relating to the ending state of said physical attributes;
- wherein said physical attributes comprise directional albedo parameters.
Dependencies are inferred from the claim text.