OCTA (STAR) PVD: A different approach of image steganopgraphy

Pixel Value Differencing (PVD) steganography method embeds secret data in images based on spatial information. In Tri Pixel Value Differencing (TPVD) steganography method the data is hidden in 2 × 2 Square block. In PVD and TPVD steganography histograms generated are having steps at regular intervals. These steps indicate that there is certain data hidden in the image. A critical literature survey indicates that the PVD and TPVD methods are very vulnerable to histogram based attacks. So the idea is to have effective image steganography application in terms of better security and better payload capacity. In the proposed OCTA (STAR) PVD method we modified the existing TPVD method by considering 3 × 3 pixel pairs instead of 2 × 2 pixel pairs. Due to this the number of available pairs for data hiding is to 8 as compared to TPVD´s 3. So more data is hidden with better security.