Enhancing the imperceptibility of image steganography for information hiding

In this paper, an image steganography approach is presented dividing the cover image into 2×2 non-overlapping pixel blocks. The upper-left pixel of that block embeds a certain number of bits of the secret bit stream. Whereas, the remaining pixels of the same block embed the secret data using a modified version of the pixel-value-differencing (PVD) method that considers embedding secret data into both horizontal and vertical edges; unlike traditional image steganography approaches. The experimental results show that the proposed approach perceptually outperforms competing approaches in terms of the standard PSNR and the complex wavelet SSIM index. In turn, the imperceptibility of the stego-image is improved with a comparable bit-embedding capacity.