(IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 7, No. 1, 2016 Non Correlation DWT Based Watermarking Behavior in Different Color Spaces Mehdi Khalili Dept. of Computer and Informatics Engineering Payame Noor University Tehran, Iran Mahsa Nazari Dept. of Computer and Informatics Engineering Payame Noor University Tehran, Iran Abstract—There are two digital watermarking techniques. Digital watermarking techniques based on correlation and digital watermarking techniques that are not based on correlation. In previous work, we proposed a DWT2 based CDMA image watermarking scheme to study the effects of using eight color spaces RGB, YCbCr, JPEG-YCbCr, YIQ, YUV, HSI, HSV and CIELab, on watermarking algorithms based on correlation techniques. This paper proposes a non correlation based image watermarking scheme in wavelet transform domain and tests it in the same color spaces, to develop studying, reach a comprehensive analysis and focus on satisfying the requirements of based non coloration watermarking algorithms. To achieve more security, imperceptibility and robustness of the proposed scheme, first, the binary watermark image encodes by applying ATM, CCM and exclusive OR. Then, the scrambled watermark embeds into intended quantized approximation coefficients of wavelet transform by LSB insertion technique. Keywords—ATM; CCM; DWT2; color spaces; non correlation watermarking technique I. INTRODUCTION In this modern era, computers and the internet are major communication media that bring the different parts of the world into one global virtual world. As a result, people can easily exchange information and distance is no longer a barrier to communication. However, the safety and security of long- distance communication remain an issue. This is particularly important in the case of confidential data. The need to solve this problem has led to the development of watermarking schemes [1, 2]. A digital watermark is an identification code that carries information about the copyright owner, the creator of the work, the authorized consumer, etc. It is embedded in the multimedia data, digital, serial number, text, image, logo and other types of information, and plays a role of copyright protection, signs product, secret communications, confirming data belonging, identifying data authenticity and so on [3]. Typical watermarking schemes embed the watermark by altering coefficients related to the original source in some specific domain, including the spatial domain methods, transform domain techniques using discrete cosine transform (DCT), discrete wavelet transform (DWT) and discrete Fourier transform (DFT), or singular value decomposition (SVD) and vector quantization (VQ) domain schemes [4, 5]. Among frequency domains, the discrete wavelet transform can strengthen the resistance under attacks [6, 7]. Although there are no universal requirements to be satisfied by all watermarking applications, some main directions are generally considered by the research studies. In order to be effective, the watermark should be perceptually invisible for a human observer (i.e. the imperceptibility property) and its detection should be successful even when the watermarked content is attacked (i.e. the security and robustness property) [8]. There are two digital image watermarking techniques. Digital watermarking techniques based on correlation and digital watermarking techniques that are not based on correlation [9]. In watermarking techniques based on correlation, to extract the watermark, the correlation coefficients between the watermarked content will calculate with a definite threshold and if the correlation is more than the defined threshold, it means that the watermark detector determines watermark image from the content of the image [10, 11]. The simplest example of a watermarking technique that is based on non correlation is the method of least significant bits insertion (LSB). In this method, the least significant bits of many components are watermarked by information [12]. Because the least significant bits do not include visual important information, therefore we can easily replace many of watermarked bits with this level [9, 13]. On the other hand, color spaces abound, but not all of them are appropriate for the entire spectrum of image processing tasks. A color space is a mean of specifying colors, and they can be classified into three basic parts: HVS (human visual system) based color spaces (e.g. RGB, HVS, HSI and etc.), application specific (e.g. YCbCr, YUV, YIQ and etc.) and CIE color spaces (e.g. CIELab and etc.) [14]. The motivation for this study is that there is not a common criterion about which color space is the best one to satisfy image watermarking requirements. There are a lot of studies which describe and use a lot of color spaces to improve each watermarking property, but each study usually focuses on a specific color space, showing the results obtained with that color format. Although, In [14], a DWT2 based CDMA image watermarking scheme proposed and tested in eight color spaces RGB, YCbCr, JPEG-YCbCr, YIQ, YUV, HSI, HSV and CIELab, to explore how the choice of color space, influences the results of correlation based image watermarking algorithms with respect to changes in watermarking anticipating properties such as imperceptibility and robustness against different attacks, but a similar study on based non correlation image watermarking has not done yet. Therefore, in this paper, using wavelet transform, a non correlation based image watermarking scheme proposes and testes in the same color 526 | Page www.ijacsa.thesai.org