An image encryption scheme based on image complexity

This paper is concerned with the image encryption scheme based on image complexity, which can satisfy the need of multi-level quality of service. Firstly, each subband of DWT (Discrete Wavelet Transform) coefficient is analyzed. Then, image is cut into blocks. Variances of DWT coefficients are considered as parameters to evaluate complexity of each block. Finally, as to accomplish a controllable visual effect of the encrypted image, each subblock is encrypted with the corresponding intensity according to different complexity. In the scheme, we emphasize the details of each image, which is consistent with human vision sensation. Experimental results prove that the scheme is feasible and efficient.