A New Selective Document Image Encryption Using GMM EM and Mixed Chaotic System
The selective image encryption technique protects only the region of interest in the image. The Proposed method aims at determining the significant region of the image by using clustering technique and protect it against security attacks. The Gaussian Mixture Model based Expectation and Maximization (GMM EM) clustering technique is applied here. The selected clustered region is subjected to both the confusion and diffusion, Confusion using 2D Ikeda chaotic map and Diffusion using 1D Quadratic map. The proposed work is extended for complete encryption of the image. The one level confusion using 2D Ikeda chaotic map and the two level diffusion are performed. The first level of diffusion uses 1DQuadratic map and the second level diffusion uses a small kernel. The proposed scheme is experimented for document images containing only the text, the text with image, the text fused with image and only the image. The experimental results reveal a higher degree of security of the image. The assessment parameters evaluates Peak Signal to Noise Ratio, Mean Square Error, Entropy, Correlation, Pixel change rate, Average change in intensity, Encryption time and Percentage of encryption. Results are then compared with existing methods ensuring a higher degree of security against static and dynamic attacks by the interceptor.