Embedding information in document blank space
AssigneeXerox Corporation
InventorsZhigang Fan, Reiner Eschbach
Life of this patent
Estimating the term…
Abstract
A method for embedding information in a document includes encoding information as a plurality of data carrying dot patterns. For each of a plurality of blocks of a document page to be rendered, the method includes determining whether the block is blank. Each of the plurality of data carrying dot patterns is embedded in a respective one of the blank blocks. The document with the embedded data carrying dot patterns is rendered.
Claims29
A method for embedding information in a document comprising:
- encoding information as a plurality of data carrying dot patterns;
- for each of a plurality of blocks of a document page to be rendered, determining whether the block is blank;
- embedding each of the plurality of data carrying dot patterns in a respective blank block;
- and
- rendering the document with the embedded data carrying dot patterns.
A system for embedding information in a document comprising:
- a data reception component that receives information;
- a watermark embedding component in communication with the reception component which embeds a watermark in a document to be rendered based at least in part upon the received information, the watermark embedding component identifying a sequence of blank blocks of a document page to be rendered, and embedding the information as a plurality of data carrying dot patterns, each of the dot patterns being embedded in a respective blank block.
A recipient comprising an image and a machine readable watermark embedded therein, the watermark comprising a plurality of data carrying dot patterns which each encodes data, each dot pattern comprising an arrangement of miniature marks which are substantially unnoticeable to an unaided eye, the dot patterns being each assigned to a respective one of a sequence of equally sized blank blocks to which no image data is assigned, whereby by examination of blank blocks containing no more than a threshold amount of image data, the dot patterns are retrievable and the data encoded therein interpreted.
A method for retrieving information embedded in blank space in a rendered document comprising:
- inputting image data acquired from the rendered document;
- partitioning at least a portion of a document page represented by the image data into a plurality of equally sized blocks;
- identifying, from among the blocks, a sequence of blank blocks which contain no more than a threshold amount of image data;
- for each of the sequence of blank blocks, determining whether the block includes a pattern of miniature marks which corresponds to a unique datum value stored in a data structure;
- and
- from the unique data values, retrieving the information embedded.
A system for retrieving information embedded in a document comprising:
- a detection component for generating a signal representative of image data acquired from a document;
- a data structure which links each of a plurality of predefined dot patterns with a unique datum value;
- an extraction component for extracting from the image data a watermark where present, the watermark comprising a plurality of the dot patterns, the extraction component being configured for partitioning at least a portion of a document page represented by the image data into a plurality of equally sized blocks, identifying, from among the blocks, a sequence of blank blocks which contain no more than a threshold amount of image data, for each of the sequence of blank blocks, determining whether the block includes a dot pattern which corresponds to a unique datum value stored in the data structure, and from the unique data values, retrieving the information embedded;
- and
- optionally, an implementation component for implementing a computer implemented process in accordance with the retrieved information.
Dependencies are inferred from the claim text.