Mantissa replacement steganography using LWT

Steganography is an authenticated technique for maintaining secrecy of embedded data. The novel concept of replacing mantissa part of cover image by the generated mantissa part of payload is proposed for higher capacity and security. The Lifting wavelet Transform (LWT) is applied on both cover image and payload of sizes a * a and 3a * 2a respectively. The mantissa values of Vertical band (CV), Horizontal band (CH) and diagonal band (CD) of cover image are removed to convert into real values. The approximation band of payload is considered and the odd column element values and even column element values are divided by 300 and 30000 respectively to generate only mantissa part of payload. The modified odd and even column vector pairs are added element by element to form one resultant vector. The column vector elements of cover image and resultant column vector elements of payload are added to generate stego object column vector elements corresponding to vertical, horizontal and diagonal elements. The inverse LWT is applied to generate stego image.