Methods and systems for watermarking documents
AssigneeZoho Corporation Private Limited
InventorsSujatha S. Iyer, Balachandar S, Ramprakash Ramamoorthy, Shailesh Kumar Davey
Life of this patent
Estimating the term…
Abstract
Described are methods and system that digitally watermark documents using an encoding scheme that embeds unique identifiers into the files by perturbing the relative heights of words to create patterns that are imperceptible to the human eye but decodable to recover the identifiers. The unique identifiers can be precoded before they are embedded in the documents.
Claims21
A method for encoding a user identifier in a document, the method comprising:
- extracting text elements from the document, each of the text elements having respective renderable dimensions;
- and
- encoding the user identifier into the renderable dimensions of the text elements.
A method of identifying a user associated with a document, the method comprising:
- detecting text elements in the document, the text elements having respective dimensions;
- and
- decoding a user identifier from the dimensions.
A document comprising:
- rendered or renderable text elements having rendered or renderable dimensions;
- and
- a user identifier encoded in variations in or between the rendered or renderable dimensions of the text elements.
A system for encoding a user identifier in a document, the system comprising:
- memory to store the document;
- and
- at least one processing unit coupled to the memory, the at least one processing unit to read text elements from the document, each of the text elements having respective renderable dimensions, and encode the user identifier into the renderable dimensions of the text elements.
Dependencies are inferred from the claim text.