Hiding the Secret Image Using Two Cover Images for Enhancing the Robustness of the Stego Image Using Haar DWT and LSB Techniques

Steganography techniques play vital role in hiding the secret information and hence to secure the data during transmission and storage. In this paper initially one of the two cover images is chosen and the secret image is hidden in this cover image using LSB technique. Exclusive OR (EXOR) operation is performed on the LSB bits using the MSB bits for better security. The other cover image is chosen and the previously constructed stego image is embedded in this cover image using Haar wavelet transform. Using Haar DWT the image can be transformed to approximate band (LL) and detailed bands (Horizontal band(LH), Vertical band(HL), Diagonal band). Detailed bands consist of lesser energy of the original signal when discrete wavelet transform is applied on the original signal. Hence the coefficients of the detailed bands are used to hide the secret information. The quality of the stego image is analysed using the PSNR value.