An Image Hiding Method by Applying Tree Structure on Linking Pixels

In this paper, all bits of adjacency pixels are linked with a XOR operator. If the XOR value of a pixel is not compatible with its corresponding secret bit, the way to change the XOR value of a pixel can modify not only the pixel itself, but also its adjacency pixels instead. According to this concept, the proposed embedding algorithm is to find the least quantity of pixel modifications such that the secret data can be embedded into a cover image. However, there are many modification ways to make the XOR values of pixels equal to the corresponding secret data. To decide which pixels should be modified and how they should be modified, the proposed method produced the possible modified ways in the way of the tree structure arrays. Through those arrays and the backtracking procedure, the way of fewer pixel modifications in the embedding phase can be achieved.