1. Introduction
In recent years digital watermarking has gained great deal of importance with the explosion of the digital media. Several digital watermarking techniques are developed to prevent the unpermitted data transmission and protect the data from the intentional and unintentional attacks. The goal of the digital image watermarking techniques is to embed a secret signal called as watermark to the cover image. The most common applications of the digital watermarking methods are copyright protection, broadcast monitoring, tamper detection, authentication and integrity verification, fingerprinting, content description and secure communication.