A blind watermarking technique based on DCT psychovisual threshold for a robust copyright protection

This work presents a blind watermarking technique based on a psychovisual threshold for a robust copyright protection. Psychovisual threshold can provide a trade-off between imperceptibility and robustness of the watermark. This paper proposes a new watermarking scheme where watermarks are embedded on some selected coefficients of DCT frequencies considering psychovisual threshold. The embedding regions are determined using a modified entropy to indicate less distortion areas. Furthermore, the watermark image is scrambled before embedding to provide additional security. The proposed scheme is tested under different types of signal-processing and geometric attack. The experimental results show that our scheme produces higher imperceptibility and robustness of the watermark than the existing schemes.