Zero Watermarking Method Based on Enhanced Bit-Plane

Abstract

Traditional watermark embedding introduces inevitably some perceptible quality degradation of the host image. Another problem is the inherent conflict between imperceptibility and robustness. However, the zero-watermarking technique can extract some essential characteristics from the host image and use them for watermark registration and detection. The original image was decomposed into series of multiscale and directional subimages after lifting wavelet transformation (LWT). The high order bit-plane of low-frequency subimage and watermark image are inputs of the cellular neural network (CNN), and the zero-watermarking registration image is the output. To investigate and improve the security and robustness, the original watermark and registration image are scrambled or encrypted. The watermark image can be extracted from the secret image. This algorithm is simple and robust. The proposed method is also simple for hardware realization.