An Image Authentication Technique in Frequency Domain using Genetic Algorithm (IAFDGA)
Jyotsna Kumar Mandal · International Journal of Software Engineering & Applications · 2012
In this paper Genetic Algorithm based image authentication technique in frequency domain using Z transformation (IAFDGA) has been proposed.A 2×2 mask is taken from the source image in row major order.Z transformation is applied to transform it into frequency domain.Six bits are embedded in each sub mask into the second and third transformed coefficients.The sub mask is then transformed into spatial domain using inverse Z transform.Embedded image mask of size 32 bits are taken as initial population.New Generation followed by Crossover and Mutation are applied on it.To obtain New Generation , minimum coefficient of the mask is chosen, if the minimum coefficient is negative then subtract the minimum coefficient from each coefficient of the mask so that extraction of hidden bits are ensured.For the Crossover operation consecutive bit-wise XOR is performed on the rightmost three bits of each byte in three steps.It will form a triangular form and the first bit of each step is taken as the output.Right most two LSBs of two consecutive pixels are swapped with each other as a part of Mutation operation.Genetic algorithm is applied to enhance a layer of security level.At the time of embedding dimension of the authenticating image followed by the content are embedded.Reverse process is followed at the time of extraction.High PSNR obtained for various images compared to existing conform the quality of invisible watermark IAFDGA.Large capacity as compared to existing algorithm [1] ensured the high payload of the scheme.