Image Steganography using Combined Nearest and Farthest Neighbors Methods

Security is invariably a significant concern during communication. With the ease of communication, there is always a pending threat of intrusion. Steganography is one such way to achieve security by concealing confidential information within a more innocent looking media like image, audio, video etc. In this paper, a new technique is proposed that uses the relationship of a pixel with its Nearest Neighbor and Farthest Neighbor to hide secret information into that pixel. The cover image is divided into2x2 non-overlapping blocks. According to the vulnerability of the relationship among the pixels, blocks are labelled as Stable and Unstable. The Stable block hides ‘k’ secret while unstable block hides ‘n’ secret bits. 25 types of different set of ‘k’ and ‘n’ is examined to evaluate the performance of proposed method. 2k method is applied to improve the quality of stego image. The experimental result shows that the proposed technique hides a significant number of secret bits with high PSNR. While compared with other existing methods, the proposed method achieves a much higher visual quality than that of those methods.