Robust Color Image Watermarking Techniques Based on DWT, DCT and SVD in Different Color Spaces

Within the last decade, with the development of communication technologies and the increasing growth in the internet has become insecure, so it created different techniques to solve this problem. One of these techniques is the digital watermark, which provides the protection of property rights. In this thesis, we suggest new techniques of watermarking image aim to increase the degree of robustness of the watermark against various attacks and to increase the imperceptibility of the watermark image. Also these techniques aim to ensure the watermark image using Arnold transform where the watermark is available only to a legitimate user. The proposed approaches of watermarking image based on DWT, DCT and SVD have been applied on gray and color images in different color spaces like RGB, YIQ and YCbCr. Therefore, we have seven proposed algorithms namely: a gray image watermarking technique, an image watermarking technique in RGB color space (using a gray watermark image), an image watermarking technique in RGB color space (using a color watermark image), an image watermarking technique in YIG color space (using a gray watermark image), an image watermarking technique in YIQ color space (using a color watermark image), an image watermarking technique in YCbCr color space (using a gray watermark image) and an image watermarking technique in YCbCr color space (using a color watermark image). The difference between these algorithms is the type of watermark and the colorspace used (gray or color image: RGB, YIQ or YCbCr). To test the performance of proposed approaches, we calculated the PSNR and the SSIM. The best proposed approach which gives high robustness and imperceptibility of the watermark image against different attacks is an image watermarking technique in YIQ colour space (using a gray watermark image). And, the worst proposed approach which gives low robustness and low imperceptibility of the watermark image against different attacks is an image watermarking technique in YCbCr color space (using a color watermark image). In addition, our proposed approaches give high imperceptibility and high robustness of the watermark image when compared with other techniques [17][22][23]. Through the results, it has been verified superiority of our proposed approaches on many techniques. Our proposed approaches have high robustness of the watermark against various attacks with high quality for the watermarked image and security of the watermark image. Keywords: Watermarking Image, robustness, imperceptibility, PSNR, SSIM.