Digital image watermarking by using intermediate significant bits in gray scale images

Abstract

The rapid growths of the computer technologies have been increased over the last half century in terms of amount and complexity of data. Also, access to the data has become much easier due to rapid growth of the networks such as Internet. Furthermore, most of the people use image to represent information and it is transferred throughout the internet. Digital watermarking techniques are used to protect the copyrights of multimedia data by embedding secret information inside them, for example, embedding in images, audios, or videos. Digital Image watermarking also has been used to detect original images against forged images by embedding an evidence of the owner of image. Digital Image watermarking can be categorized into two domains namely; spatial, and frequency domains. The former has been chosen for the current research and some remaining problems have been studied such as imperceptibility, security, and robustness of watermarked image. A repeated method is proposed to solve the problem of robustness, and a Zig-zag algorithm is also recommended to change the order of embedding in watermarked image. Furthermore, the proposed method aims to embed watermark in different bit planes of host image which can improve both the visual quality and robustness. To evaluate the proposed technique, some attacks have been applied for the approach and the experimental results have shown that the proposed technique successfully withstood against most of the attacks, and at the same time preserved the watermarked image quality.