9th International Marmara Sciences Congress (Autumn 2022), Kocaeli, Turkey, 9 - 10 December 2022, pp.1-5
Data hiding studies that using the images as carriers are still remain popular. One of the important reasons for this case is that it is easier to manipulate images than other carriers. In addition, images are highly preferred because they offer higher capacity than other carriers. Reversible data-hiding (RDH) approaches are also an important research area. RDH aims to restore the stego object to its original state after the extraction of secret data The most important disadvantage of reversible data hiding methods is that the data hiding capacity is lower than classical methods. In this study, in order to increase the capacity of the most known RDH method, namely the histogram shifting-based method is proposed to use double-sided shifting of the histograms of the adaptive sub-blocks in the image. In the proposed study, the peak value in the histogram of each block in the image divided into square sub-blocks is preserved, while the pixel values on both sides of the peak value are shifted and emptied. For data hiding, secret messages are added to both gap regions. After the data extraction is done successfully, the carrier image is returned to its original state. Experimental studies for Lena image is showed that while the square sub-block size was 128x128, 48.34 dB PSNR and 0.998 SSIM values were obtained for 12563 hidden bits. While the sub-block size was 8x8, 49.03 dB PSNR and 0.995 SSIM values were obtained for 33917 hidden bits. Although the hiding capacity increased as the block size decreased, there were minor changes in the visual quality metrics.