Adaptive Spatial Steganography Based on the Correlation of Wavelet Coefficients for Digital Images in Spatial Domain

How to define the pixel's embedding distortion is a key problem of image adaptive steganography. This paper proposes an adaptive spatial steganography in spatial domain based on the correlation of wavelet coefficients for digital images according to the principle of minimizing a suitable defined distortion. Firstly, one-dimensional high-pass and low-pass filters are used to construct directional filters. Secondly, do direction filtering to images through the direction of horizontal, vertical and diagonal, and design the distortion cost function according to the correlation of wavelet coefficients. Finally, the secret message is embedded by STC (Syndrome Trellis Code) according to the pixel's embedding distortion. The experiment results illustrate that the proposed method not only make the embedding region focus on the texture regions whose content is complex, but also can resist the common steganalysis detection effectively.