Fast turtle shell-based data embedding mechanisms with good visual quality

Abstract

Data hiding for digital images is referred to as an approach of embedding confidential or sensitive information into a cover image. Besides embedding capacity and visual quality, computational complexity is the most important criterion to evaluate the performance of a data hiding method. At present the turtle shell matrix is used extensively in data hiding; unfortunately, most of the turtle shell-based data hiding methods are still time consuming. In this paper, we proposed two enhanced real-time turtle shell-based data hiding schemes. One applies the original turtle shell matrix to guide data embedding, achieving an embedding rate of 1.5 bpp; while the other slightly modifies the structure of turtle shell matrix in such a way that each edge digit is increased by eight, resulting in an embedding rate of up to 2 bpp. The main idea of both proposed schemes is to map each cover pixel pair onto the original or modified turtle shell matrix to find out its associate set for embedding a secret digit. Then, the cover pixel pair can be modified with minimum distortion according to the associate set. Experimental results confirm that the execution time for both of the proposed schemes is much shorter than previous methods, along with better visual qualities. Therefore, the proposed schemes offer lower computational complexities to be applied to various real-time applications.