Image Steganography using Improved Exploiting Modification Direction

The present approach is based on the Improved Exploiting Modification Direction (IEMD) method of image steganography. This approach increases security and ensure that the message can’t recover without knowing the embedding equation and secret key. Now as technology is improving the significance of data secrecy and clandestine communication is increased, to fulfill this requirement we have introduced Vigenerer cipher to encrypt our secret text, further to increase the secrecy of original data we have to convert 2D image into 1D data stream by using zigzag traversing, and by choosing value n i.e. number of pixels required, to encrypt $(M=2^{\ast}n+1)$-ary number and number of digits D in M - ary number that increase external attacker difficulties and improve data security. This IEMD method can hide an $(M=2^{\ast}n+1)$-ary number just modify a bit from n pixel values that can achieve embedding capacity 1 bpp without disturbing the image quality. However considering minimum value of n i.e. n=2 gives min. PSNR is 57.14 dB. Further increasing n value PSNR is also increases up to 59.67dB with maintaining embedding capacity is approximately 1 bpp. attacker on stegographic image.