A blind watermarking algorithm based on HVS applied for covert communication

There are two ways for transmitting data in a secure manner: Cryptography and steganography. Digital watermarking is a specific branch of steganography, which can be used in various applications, including covert communication, owner identification, authentication and copy control. In this paper, we proposed a blind adaptive watermarking algorithm based on HVS is proper for covert communication. The secret information that can be seen as a watermarking is hidden into a host image, which can be publicly accessed, so the transportation of the secret information will not attract the attention of illegal receiver. With our approach, the secret information is embedded in the wavelet domain. By the background luminance and the texture mask characters of HVS, we divide the wavelet coefficients of carrier image into different classes. According to the classes of the wavelet coefficients the watermark image is embedded. The result of our experimental shows that this approach is imperceptible and robust some image processing such as JPEG lossy compression, cropping, median filtering, grads sharpening, Gaussian white noise attacks and so on.