Patent ID: 7894626
Filing Date: 2011-02-22
Classification: G06T,H04N

Abstract:
1. A method creating digital watermarks in grayscale images, comprising: receiving the first image to be watermarked; determining the first watermark to be embedded in the first image; embedding the first watermark into the first image by halftoning the first image using a three-dimensional threshold array having a phase shift value as an input and a first halftone structure defined by the spatial vectors V outputting a first watermarked grayscale image containing the first digital watermark embedded with the first halftone structure; receiving the second image to be watermarked; determining the second watermark to be embedded in the second image; embedding the second watermark into the second image by halftoning the second image with a three-dimensional threshold array having a phase shift value as an input and a second halftone structure defined by the spatial vectors V outputting a second watermarked grayscale image containing the second watermark embedded with the second halftone structure.