A 9/7 wavelet-based lossless data hiding

In this paper, a lossless data-hiding approach is presented based on quantized coefficients of discrete wavelet transform (DWT) in the frequency domain to embed secret message. Using the quantized coefficients for 9/7 wavelet filter in DWT, we embed secret data into the successive zero coefficients of the medium-high frequency components in each reconstructed block for 3-level 2-D DWT of a cover-image. The procedures of the proposed system include embedment, extraction, and restoration. Experimental results show that the proposed method can achieve high embedding capacity and acceptable image quality of stego-image, and data reversibility.