Integer wavelet transform based high performance secure steganography scheme QVD-LSB

n integer wavelet transform (IWT) based image steganography technique is proposed to prevail the embedding capacity constraints in this domain. Quotient value differencing (QVD) and 2-least significant bit (2-LSB) techniques are employed in the high frequency subbands. It divides the bit region of each coefficient of high-frequency subbands into two halves and two techniques are used concurrently in each half of the bitplane. The high-frequency subbands are divided into non-overlapping 3 × 3 blocks and confidential messages are concealed in eight directions within each block. The low-frequency subband is fragmented into non-overlapping 2 × 2 blocks. Since the human eye cannot tolerate more changes in low-frequency coefficients, one-fourth of the approximation subband (LL) is used to hide confidential messages. The method attains an average embedding capacity (AEC) of 3.14 bpp. To increase the safety of the technique, the confidential messages are hidden in a non-sequential way. The work resists the steganalysis test of StegExpose and outperforms the tests of the standard tool StirMark benchmark 4.0.