Improving reversible histogram based data hiding schemes with an image preprocessing method

Abstract

This paper presents two edge detectors and a preprocessing algorithm for histogram based data hiding schemes. The proposed technique takes advantage of the edge detectors to segment the image into plain and textured areas. The plain areas are selected for embedding where a histogram based scheme is used to embed information in these areas. Since in the plain areas, pixel intensities are close to each other, with the proposed preprocessing algorithm the number of shifted pixels for the same amount of hidden data capacity are decreased which results in a better transparency. To validate the efficiency of the technique two of the best known histogram based schemes which use prediction and interpolation are implemented and results are compared with and without the preprocessing scheme. The experimental results show that the histogram based methods with preprocessing algorithm, under the same capacity, have better transparency than the schemes without preprocessing. This scheme improves capacity, even by 200%, at equal distortion, or about 4 dB improvement in PSNR, at the same hiding capacity.