An improvement of diamond encoding using characteristic value positioning and modulus function

The diamond encoding technique controls payload and image quality by a k value. Although a small increase in k can increase payload, it also increases image distortion. In this paper, we proposed an improvement scheme to the diamond encoding technique for reducing image distortion during a k change. Another aim is to increase payload size. A square matrix conversion of the diamond matrix is used to lower the MSE values in high payload when k = 3. A lower MSE reduces image distortion. In low payload, that is when k changes from 1 to 2, a one dimension matrix modulus is used to reduce image distortion. Experimental results showed that payload may be increased while image quality is not significantly reduced.

► Square Matrix Encoding (SME) and Modulus Function Encoding (MFE) are proposed. ► SME is used to improve image quality when k is between 1 and 2 in diamond encoding. ► MFE is used to improve image quality in high payload when k = 3 in diamond encoding. ► SPAM analysis on SME and MFE showed higher data security than LSB, LSBM, EMD and DE. ► Results showed improved image quality, increase payload and higher data security.