A Robust Watermarking Approach using DCT-DWT

This paper presents a robust watermarking technique for color and grayscale image. The proposed method involves many techniques to conform a secure and robust watermarking. In the proposed technique the watermark is embedded in 3 level of DWT (Discrete Wavelet Transform) and before embedding the watermark image is passed through chaotic encryption process for its security, other important thing is that in the proposed method watermark is embedded in the form of DCT (Discrete Cosine Transform) with special coefficient shifting algorithm to minimize the impact on main image. The performance of the proposed watermarking is robust to a variety of image processing techniques, such as JPEG compression, enhancement, resizing, and geometric operations.