Optimized Image Watermarking Scheme Based on IWT and DCT

Abstract

In the digital world, multimedia content and data can easily be used in an illegal way being copied, modified and distributed again. Watermarking is identified as a major technology to achieve copyright protection. The digital image watermarking process is definite as to insert information of digital into a digital signal. Watermarking is defined as a technique that embedsdata into digital contents such as text, still images, video, and audio data without degrading the overall quality of the digital media. This is an efficient solution to avoid illegal copying of information from multimedia networks. The important qualities of watermark are robustness and imperceptibility. In this paper, we propose a combined watermarking scheme of images based on Integer wavelet transform and discrete cosine Transforms. The imperceptibility of image changes according to different values of the scaling factor that is used in embedding. We choose an optimised scaling factor that gives us a good imperceptibility of the watermarked image as well as good capacity and robustness.