A Steganographic Method Based on Pixel Block Differences in Grayscale Images

Nowadays, protecting shared data from interception on public networks is critical. Steganography, an approach to concealing data, emerges as a practical remedy to confront this challenge. However, hiding confidential information within a digital medium, such as an image, often results in the degradation of visual quality. This decline can elicit suspicions among unauthorized users regarding the potential presence of concealed information. Over time, researchers have devised various steganographic algorithms to alleviate the substantial image distortion resulting from the data embedding process. Despite these endeavors, achieving a stego image of elevated quality that carries concealed data remains an enduring challenge. This study introduces a steganographic methodology grounded in the logic of difference expansion (DE), intending to augment the quality of the stego image for a specified payload size. The experimental outcomes showcase a Peak signal-to-noise ratio (PSNR) reaching 62.7512 decibels (dB), underscoring the superior efficacy of the proposed method.