Research Of Watermarking Based On Fractal And Wavelet In Graphics Secure Transmission

In the global network environment, the convenience of information exchange induces a lot ofdangers in information security, which attracts more and more attention. However, Traditionalcryptography has difficult to meet the increasingly diverse and complex requirements of currentinformation security. Information hiding technique can hide a secret signal into the redundancy of thecarrier signal, and does not affect its normal effect, which can effectively improve the security andreliability of the transmission system.Based on the research of information hiding and digital watermarking, and the current securetransmission system, this paper proposes an graphics secure transmission system based on fractaland wavelet transform. The system includes secret image pre-processing module, hiding module andextracting module, which can ensure the security of the secret image transmission.Firstly, based on the digital watermarking in wavelet domain, this paper proposes a digitalwatermarking algorithm for color images based on JND and zerotree coding, Wavelet transform ofdifferent levels is applied to the scrambled watermark and the original image. The coefficients of thewatermark are embedded in the subbands of the color image from the low frequency to the highfrequency according to the significance, at the same time, within the subband, the significantcoefficients are selected for embedding in terms of their importance based on zerotree coding. Theembedding intension is decided by just noticeable difference threshold. The experimental results showthat the algorithm has good invisibility and robustness.Secondly, based on the research of current information hiding algorithm, the application offractal image coding using DWT in information hiding, and the proposed color image watermarking,this paper designs an information hiding algorithm based on fractal and wavelet transform. At first,the secret image is scrambled. After wavelet transform is applied to the original image, zerotree areais selected based on zerotree coding. Then the secret information is embedding in the better matchedimage trees based on fractal matching distance and JND threshold in non-zerotree area, and theremaining secret information is embedding in the zerotree area. The experimental results demonstratethat the algorithm has good transparency and robustness to common image attacks.Finally, the system is designed and implemented, which is initally applied to secure transmissionof outsourcing management system. The experimental results indicate that the system can ensure thesecure transmission under normal and third-party interception and interference attacks environment.