Robust method of digital image watermarking using SVD transform on DWT coefficients with optimal block

Over the last few years, development of internet and technology of media, the protection of copyright have become very important. To protect multimedia data against illegal copying and transferring, the insertion of a signal (digital signature, watermark) has become a duty without modifying quality of the original image, the goal of this operation is to identify the owner and protect his intellectual property. Digital watermarking has been proposed as a solution to solving the copyright problem by introducing invisible data (watermark) into original image. In this paper, we propose a study of digital images watermarking. This study is achieved by inserting watermark in different coefficients of DWT (LH, HL, HH) using SVD transform by searching the optimal block that have the maximum entropy which can be used to insert the watermark in original image. The experimental results show the different results of PSNR for each coefficient of DWT and the robustness against most attacks.

I. Introduction

The World Wide Web has evolved significantly in different areas, especially multimedia technologies, involving extensive use of digital data such as images and videos. The information that vehicle in this world is a large database that requires an efficient way to meet the intellectual property [1]–[2]; this condition has become an important factor in the emergence of this technology. The digital image watermarking has been a reliable way to ensure that intellectual property [3]–[4]. Digital watermarking has many applications in several areas, such as the application of copyright protection, authentication, and secret communication [5]. Digital image watermarking means a discipline of applied mathematics that studies the digital images and their transformations in order to improve their quality or to extract information [6]–[7]. This discipline involves inserting an invisible mark (digital signature) in an image or other digital documents. The inserted mark must be known by the owner or the distributor, and it must meet three basic requirements: imperceptibility, robustness and capacity [8]–[9]. Imperceptibility means that the deformation of the image must be low enough that the user cannot distinguish the difference between the watermarked image and the original image [10]. The robustness is the power to recover the inserted even if the watermarked image was manipulated by attacks [11]. Capacity of the watermarking system is defined as the maximum amount of information that can be embedded in the original image [12].