An Improved PPVO Data Hiding Scheme

The pixel-based pixel value ordering (PPVO) which each pixel is predicted using its sorted context pixels greatly improves the embedding capacity compared with the traditional PVO algorithm. In the PPVO algorithm, the prediction value is more accurate if there is a strong correlation between the target pixel and its context pixels. Otherwise, the prediction value is inaccurate. For higher embedding capacity and image quality, an improved PPVO is proposed. In the proposed scheme, the target pixel is predicted by a specific prediction method first. Then, the predicted value is added to the context pixels as the additional pixel value. In the process of embedding data, the target pixel is predicted by using the maximum / minimum value of the context pixel vector. Experimental results demonstrate that the embedding capacity of proposed method is larger than that of PPVO. The marked image quality of proposed method is also better than that of PPVO.