A digital data hiding scheme based on pixel-value differencing and side match method

This paper proposes a new data-hiding scheme based on pixel-value differencing (PVD) in which 3-by-3 blocks are used to hide data within nine-pixel groups. The PVD scheme and the side match method are combined to ultimately produce eight groups of pixel-value differences, enabling maximum hiding capacity while maintaining an acceptable peak signal-to-noise ratio (PSNR). Experimental results demonstrate that the hiding capacity of this scheme can reach a maximum of 808,760 bits with a PSNR value of 32.0283dB, which is difficult to detect with human vision. The results of a performance comparison with those of PVD hiding schemes proposed by other researchers confirm that the proposed scheme has a higher capacity than the other methods while maintaining an acceptable PSNR, demonstrating the superiority of the proposed hiding scheme. Finally, to assess the suitability of the proposed method to databases with different patterns, a further 2260, 9074, and 10,000,512x512-pixel greyscale images were respectively selected from the NRCS, BOSS, and BOWS2 image databases as raw images. The proposed hiding scheme was used to hide data and generate steganographic images in these raw images. Experimental results show that the minimum PSNR mean value is 35.33dB, while the minimum mean value of the hiding capacity is 720,572 bits. These results confirm the suitability of the proposed hiding scheme for image database patterns.