Integer Wavelet Transform based Secured Image Steganography using LSB and Coefficient Value Differencing

A steganography technique based on the Integer Wavelet Transform (IWT) is proposed. High-frequency coefficients are exploited more to embed the confidential message since they are less sensitive to the human eye. Based on this notion, the 2-LSB method is employed in the wavelet coefficients of the approximation subband which contains most of the signal energy and the 4-LSB method is applied in the wavelet coefficients of the diagonal subband. The Coefficient Value Differencing (CVD) method has been introduced in the horizontal and vertical subbands. To obtain the highest embedding capacity with an acceptable distortion, a threshold value has been applied in the CVD method. The proposed technique achieves an average embedding capacity of 2.28 bpp for all the stego images while maintaining a lower distortion. It shows strength against the standard tool, StirMark Benchmark 4.0, and withstands the steganalysis attacks.