An Image Steganographic Method Based on Block-wise Pixel-Value Differencing

In order to increase the hiding capacity, we proposed a partitioning scheme based on pixel-value differencing (PVD) to embed data in gray scale images. The decision of the partitioning result is decided by the one with more edge-like modes. The main idea of the proposed method is to find more edge areas so as to hide more secret data by reason of the characteristics of human vision resolution which have a larger tolerance in edge areas than in smooth areas. In addition, a further altering process is proposed to ensure the hiding data can be correctly extracted. From the experimental results, all of the stego-images keep high visual quality and have large hiding capacity.