Enhanced pixel value modification based on modulus function for RGB image steganography

Digital image steganography is one the best security measures to be adopted while exchanging multimedia data via the public network. Data can be exchanged in the form of text, audio, video or image. Therefore, securing communication is ideal since data must be delivered to the intended recipients without any alterations. That is, data have to be received exactly as they were sent. Recently, several methods that deal with increasing the embedding capacity and the quality of the stego image have been already implemented. Additionally, with reference to the literature study, in most of the existing methods developed based on pixel value modification, two pixels are required for concealing one digit of the secret data which is relatively low. Thus, to increase the embedding capacity and security which are desirable for any image steganographic algorithm, another method which conceals data by modifying pixel values is suggested in this paper. Different from the previous method which only hides data based on modulus three function, the suggested method can handle any modulus function, i.e., the limitations encountered in the previous method are completely removed. This allows one digit of the secret data to be concealed in each pixel. Moreover, the effect of varying modulus function is also analyzed. The experiment shows that the suggested enhanced-PVM does achieve good performance. Besides, good embedding capacity and PSNR are achieved while using modulus 2, 3 and 4. On the other hand, for modulus 5, 6 and more, the embedding capacity changes slightly.