Data hiding algorithm with high payload based on pixel pair matching

The ultimate goal of an steganography algorithm is to carry as many bits as possible without introducing any detectable artifact into the cover object. However, embedding quality and payload have an antagonistic relationship. Then, people often make a tradeoff between them depending on their different desires. In this paper, a new steganography algorithm for grayscale images with large payload and acceptable visual effect is proposed. We use a group of functions to guide cover pixel pairs" modification and imply two secret digits base-9 numeral system one time. From the experimental results, the embedding capacity of the proposed algorithm achieves 3.1699 bit per pixel, which is much larger than that of the published works, while the visual quality of stego images is acceptable too.