Method of Information Hiding Based on the Theory of Wavelet Transform

In combination of the advantages of the optical encryption technology and optical hiding technology, this paper is going to reveal the way of hiding the encrypted result obtained from scrambling technology in the low-frequency coefficients of secondary discrete wavelet transform domain of another public image. Meanwhile, the information in different pixels is hidden by different coefficient matrixes generated by chaos technology in the hiding process. It makes the encrypted result more difficult to decipher. The proposed method is proved to be a valid approach for hiding the confidential information as secret image in another non-confidential image via computer simulation and validation. The quality decline of the carrier image is unapparent, which is unlikely to cause the attackers' attention. This method can effectively resist the influence of noise, cutting, compression and other attacks. What's more, the broad key space and good robustness are of high practical value.