Blind Watermarking Using DCT and Fractional-Order Lorenz System

Blind Watermarking Using DCT and Fractional-Order Lorenz System

This paper presents a new blind watermarking system based on the Discrete Cosine Transform (DCT). The system's security is increased by encrypting the watermark image using the fractional-order Lorenz system. After converting the cover image to the YCbCr color domain, DCT is applied on the Y channel and embedding of the encrypted watermark is performed in the frequency domain. The fractional-order Lorenz system has more parameters than the integer order system, which increase the length of the system key and make it secure against brute-force attacks. Although blind detection of the watermark is not easy, the proposed algorithm successfully detects the hidden watermark by using statistical properties of the DCT coefficients. Standard imperceptibility and robustness measures are used to evaluate the proposed system, and the results are good.