Data embedding in digital images using critical functions

In this paper, “uniform embedding” (independent of image contents and pixel correlations while embedding) and “adaptive embedding” (depend on image contents and pixel correlations while embedding) in image steganography are investigated. A compact steganographic embedding function is proposed to ensure the correctness and efficiency, and a pixel correlation function is utilized to discriminate the image smoothness. Two feasible image steganographic frameworks using these critical functions are presented, and some well-known image steganographic methods can be derived from the proposed frameworks. The effectiveness of the proposed frameworks is experimentally validated by constructing and testing some special data hiding methods in the case of four neighboring pixel as a processing unit. Experimental results show that the proposed methods can achieve better visual performance and statistical undetectability compared with the prior works. Another promising merit of our work is the potential to provide steganographers general-purpose strategies to acquire new image steganographic methods.