Patent · US Expired

Hardcopy watermarking

US6775393B2 · kind B2 · utility

10Cited by
5References
41Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 23, 2001
Grant dateAug 10, 2004
Priority date
Expiry dateOct 12, 2021

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2201/3284
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A digital image is hardcopy watermarked by modifying transform coefficients in a transform domain representation of the digital image, the transforms coefficients being modified according to bit values of an n-bit message. A message in a hardcopy watermarked image is identified by statistically decoding a transform domain representation of the watermarked image.

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