A Color Digital Watermark Method Based on NAM-CTC Model

With packing problem thinking, this paper proposes a non-symmetry and anti-packing pattern representation model which is short for NAM color image representation method. It presents a new color image representation algorithm based on NAM through decrypting NAM and the method of binary-bit plane decomposition (BPD) of color images. Aiming at the binary text image¿s characteristics of simple pixel, complex texture and bad immunity of information concealment, a digital watermarking embedment location choosing method has been put forward based upon CTC (compatible roughness class). Through properties´ combination, the embedment block and location which are fit for watermarking are screened out. At last, different binary text images are chosen for emulation experiment. Experimental indicates that the embedded watermark method has a strong theoretical basis and is easy to implement, and can effectively resist different types of attack.