An Optimized Transform Domain Watermarking Technique for Grayscale Images of Medical Applications
Naveen Kumar Yadav, Subramanian Selvakumar · 2018
Watermarking is a useful technique for copyright management. It is widely used in various types of digital content management application of grayscale and colour images. But as of now, there has been no method to watermark for a grayscale image using a colour image. In this paper, a unique watermarking for the grayscale image scheme in the transform domain has been proposed. The presented technique is suitable for the digital rights and security management of the diagnostic medical images in the online database. The proposed watermarking method is composed of Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD). Additionally, we have used the Firefly Algorithm (FA) to compute appropriate scaling factor to achieve higher perceptibility and robustness. Performance metrics such as PSNR, SSIM, and NCC are used to evaluate the technique. Experimental analysis shows that the proposed technique is 40-45% improved over the existing methods and almost 50% watermark is recoverable under different image processing attacks proving robustness of the technique.