A Lossless Data Hiding based on Discrete Haar Wavelet Transform

In this paper, a lossless data-hiding scheme is presented based on quantized coefficients of discrete wavelet transform (DWT) in the frequency domain to embed secret message. Using the quantized DWT-based method, 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 mainly include embedding, extraction, and restoration. Experiment results show that this purposed method can achieve high embedding capacity and acceptable image quality of stego-image, and data reversibility.