International Journal of Computer Applications (0975 – 8887) Volume 108 – No. 7, December 2014 30 Digital Image Watermarking using MSLDIP (Modified Substitute Last Digit in Pixel) Abdelmgeid A. Ali Computer Science Dept. Faculty of Science, Minia University Egypt Ahmed A. Radwan Computer Science Dept. Faculty of Science, Minia University Egypt Ahmed H. Ismail Computer Science Dept. Faculty of Science, Minia University Egypt ABSTRACT The improvements in Internet technologies and growing requests on online multimedia businesses have made digital copyrighting as a significant challenge for businesses that are related with online content distribution via diverse business models including pay-per-view, subscription, trading, etc. Copyright protection and the proof for rightful ownership are major issues related with the distribution of any digital images. Digital watermarking is one of the suggested solutions for copyright protection of multimedia data. This technique is better than Digital Signatures and other methods because it does not rise overhead. In this paper a new watermarking method based on spatial domain image steganography method called MSLDIP (Modified Substitute Last Digit in Pixel) is proposed. The main goal of this method is to hide the watermark in the pixels of digital image in such a manner that the human visual system is not able to distinguish between the cover image and the watermarked image. Also the experimental results showed that this method can be used effectively in the field of watermarking. General Terms MSE (Mean Square Error), PSNR (Peak Signal to Noise Ratio). Keywords Watermarking, SLDIP (Substitute Last Digit in Pixel), MSLDIP (Modified Substitute Last Digit in Pixel), Spatial Domain. 1. INTRODUCTION The term 'digital watermarking' was first time appeared in 1993, when Tirkel presented two watermarking methods to hide the watermark data in the cover images [1]. The success of the Internet, popular digital recording and cost effective and storage devices, and the promise of higher bandwidth and quality of service for each wired and wireless networks have made it possible to create, replicate, transmit, and distribute digital content in an easy way. The protection and implementation of intellectual property rights for digital media has become a significant issue [2]. Digital watermarking is that technology that provides and ensures security, copyright protection and data authentication to the digital content. Digital Image Watermarking is a technique to secure digital contents by integrating the original digital image and a watermark data [3]. Digital Watermarking techniques deduced from steganography, which means covered writing (from the Greek words stegano that means “covered” and graphos that means “to write”). Steganography is the science of communicating information while hiding the existence of the communication [4]. Digital watermarking techniques can be classified into two main categories on the basis of watermark embedding domain, i.e. spatial domain (which converges on modifying the pixels of one or two randomly selected subsets of images) and frequency domain (which values of certain frequencies are modified from their original) [5]. 2. BASIC WATERMARKING SYSTEM Digital Watermarking System mostly consists of two basic parts [3] (Figure 2.1): i. Watermark Embedder: is responsible for embedding the watermark image and watermark key into the cover image (original). ii. Watermark Detector: is responsible for finding and extracting the watermark image with the only using watermark key and watermarked image. This part executes on the other side after transmission of data. 3. PREVIOUS WORK In general, the embedding techniques can be categorized into two categories: spatial domain techniques or frequency domain techniques. Spatial domain watermarking techniques do a bit modifications on the pixels of one or two randomly selected subset of cover image. The general technique is LSB technique. Its modifications contain flipping the least significant bit of each pixel. The LSB technique is the simplest technique of watermark insertion. In still images, each pixel of the color image has three layers red, green and blue. Assuming that 3 bytes have been allocated for each pixel. Then, each color has 1 byte (8 bits), in which the intensity of that color can be specified on a range of 0 to 255. For example, the value of a pixel is: P0 = {R=125, G=245, B=50}. The value of another pixel is: P1 = {R=125, G=245, Fig 2.1: Basic Watermarking System