Blind watermarking techniques using DCT and arnold 2D cat map for color images

The modern era of digital communication facilities bring digital watermarking techniques which is required to copyright and authenticate owner´s information which further tracks control of regeneration and redistribution of images over untrusted and public network. In this paper, a blind digital watermarking technique has been proposed using Discrete Cosine Transform (DCT) to embed information in mid-frequency. The Arnold 2D cat map is used to shuffle the original pixel positions of watermark color image. First, the watermark image is divided into its RGB components and Arnold 2D transformation has been applied. The original cover image is decomposed into its respective RGB components. The resulting watermark images are embedded into separate components of cover images using DCT. The intensity values of watermark images are hidden in mid frequency of DCT blocks of cover images. So, it doesn´t scatter the original watermark to most visual parts of the image. The experimental results show that the algorithm is effective and robust.