Patent · US Expired

Equipment employing watermark-based authentication function

US6804376B2 · kind B2 · utility

56Cited by
440References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 28, 2002
Grant dateOct 12, 2004
Priority date
Expiry dateAug 2, 2022

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2201/3271
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Image, video, or audio data is encoded with both a frail and a robust watermark. The two watermarks respond differently to different forms of processing (e.g., copying the object may render the frail watermark unreadable), permitting an original object to be distinguished from a processed object. Appropriate action can then taken in response thereto.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.