Halftone Image Watermarking Algorithms

Halftone images are two tone images that are generally used in printing and display. It is often necessary to hide data in halftone images such as owner information, creation of date and time and information for copyright protection and authentication purposes. In several publishing applications and printers, it is necessary to embed data in halftone images. Due to this, watermarking schemes came into existence and became very popular. This book suggests different techniques for embedding data. Halftoning is a technique for converting grey scale images into two tone binary images. It is the technique for creating illusion of continuous tones and shades to the human eye. There are many algorithms for halftoning. However the classical halftoning has lesser resolution, so in order to increase the resolution a new technique was introduced which is known as dithering. This book elaborates comparison of various halftone schemes.