Reversible data hiding scheme for colour images based on pixel clustering and histogram shifting

Abstract

For some applications such as satellite images and medical images, reversible data hiding is the best solution to provide copyright protection or authentication. Being reversible, the decoder can extract the hidden data and recover the original image without distortion. In this paper, a reversible data hiding scheme based on colour palette is proposed. The pixels in a cover image are clustered using a palette to generate concentrated pixel groups. Then the secret data are concealed in the cover image by exploiting the histogram of the difference between a pixel and its group centre. Experimental results show that our method is capable of providing a great embedding capacity without making noticeable distortion. Furthermore, the proposed data hiding method is well suited to the complex images.

Keywords:

• reversible data hiding
• colour palette
• histogram
• difference expansion