Securing color images using DNA coding and cosine stockwell transformation in wavelet domain

Abstract

In this paper, a color image encoding algorithm is developed using cosine stockwell transformation and DNA coding in wavelet domain. Firstly, a color image is decomposed into its primary color components and then each component is wavelet transformed, which results four subbands for each component. The approximation subband of wavelet transformation is normalized and DNA coding is used followed by the proposed double phase encoding while the detail wavelet subbands are cosine stockwell transformed to get intermediate sub-images. The modified approximation and detail subbands are arranged by their indexing and pseudo random permutation is used to generate an encrypted image. At the receiver end, on having the exact knowledge of all the keys in correct order the original image can be recovered from the encrypted image. The bands of DCST, Tent Sine map is used to generate the random phase mask and key for pseudo random permutation is used as encryption and decryption keys. Numerical analysis and robustness of proposed work is evaluated on encrypted image to show the superiority of proposed work.