Reversible data hiding scheme based on prediction error sorting and double prediction

To consider both hiding payload and stego-image quality, a reversible data hiding scheme is proposed in this work. The prediction error of each block of size 2×2 pixels is firstly computed and sorted to obtain the ordered sequence of image blocks according to the prediction errors absolute value. And then the first [k/2] blocks with the least absolute value of errors are selected and used to hide the secret data with the length of k bits. Two bits secret data are hidden in one block by twice prediction error expansion (PEE) with different reference pixel. These two strategies not improve the maximum hiding payload, but also improve the quality of stego-image carrying the same bits of secret data. Experimental results demonstrate the proposed algorithm possesses superior properties in terms of hiding capacity and image quality.