Watermarked image generator and method of embedding watermarks into an input image
US7006256B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2002 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Apr 3, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A watermarked image generator includes a watermark data source that inputs watermark data to a watermark embedding device. The watermark embedding device halftones the input image to generate the output image made of 2×2 binary patterns, the 2×2 binary patterns forming the watermarks embedded in the output image. The watermark embedding device includes a tri-level error diffusion generator that performs tri-level error diffusion on the input image by halftoning the input image into black, white and 50% gray. A plurality of halftoning circuits successively replace each pixel of the halftoned input image with one of a plurality of the 2×2 binary patterns. The one of the plurality of 2×2 binary patterns corresponds to at least one respective bit of the watermark data when a pixel of the halftoned image data is 50% gray. The watermark data can be segmentation map data of the input image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.