A Steganographic Scheme for Color Image Authentication Using Z-Transform (SSCIAZ)

This paper deals with a novel Steganographic technique which demonstrates the color image authentication in Z-domain based on the Discrete two dimensional Z-Transform. The Transform is applied on mask of sub-image block of size 2 x 2 of spatial components in row major order for the entire image. Single bit from the authenticating secret message/image is fabricated into the real part of the frequency component of each carrier image byte. A delicate re-adjust phase is incorporated in all components of each mask after embedding, to keep the pixel values positive and non-fractional in the spatial domain. Robustness is achieved through embedding bits in variable positions of carrier image determined by a cyclic Fibonacci series. Experimental results show the enhanced performance of the proposed watermarking technique.