Steganography in Grayscale Images: Improving the Quality of a Stego Image

The development of digital multimedia has become a promising solution for maintaining the confidentiality of sensitive data by using them as carriers of secret bits. Hiding confidential data in digital media such as images, known as steganography, has gained significant attention due to their high availability on the public network. However, the researchers present a challenge of a significant drawback in embedding large payloads by keeping the quality of the stego image. To address that problem, several research works have been conducted, but there is a need to improve their work in addressing the same issue. This paper proposes a new steganographic scheme that uses differences between the neighboring pixels to conceal the secret bits in an optimized manner to the pixels of a carrier image. The experimental results obtained with the proposed method achieve a maximum peak signal-to-noise ratio (PSNR) of 87.845 decibels (dB). Moreover, the results identify a promising outperformance of our method over the existing PSNR for the same payload capacity.