Image Steganography Scheme Using Parent Child Relationship in Wavelet Domain

In this paper, a steganography scheme for digital images by using Integer Wavelet Transform (IWT) is proposed. This scheme is based on the qualified significant wavelet tree (QSWT). In this scheme, the secret data bits are embedded into largest and smallest wavelet child coefficients of a parent wavelet coefficient of a cover image. Embedding of secret data bits are performed in selected wavelet subbands only so that the embedding capacity and Peak Signal to Noise Ratio (PSNR) can be achieved maximum as PSNR value decreases with the increase of embedding capacity. Visual quality of stego images produced by the proposed scheme is acceptable by human visual system as PSNR between cover and stego images is above 40 dB and extracted secret image is exactly the same as original secret image.