Pixel Block-based Data Hiding Approach for Enhanced Payload Capacity in Spatial Domain Images

Nowadays, researchers have introduced data hiding methods to embed data within digital images to safeguard the confidentiality of sensitive information. Most data hiding techniques enable images to be fully restored to their original state after the secret data extraction process when they have been used as carriers of the secret information. Over the past few years, several data hiding approaches rooted in pixel block and difference expansion (DE) have gained prominence. However, there remains a significant opportunity for enhancing the capacity of images to accommodate large sizes of secret bits. This study proposes a novel data hiding approach based on pixel block by DE operation within all image pixels to address this challenge in spatial domain images. To experimentally test our method, we utilize seven common grayscale images for the peak signal-to-noise ratio (PSNR) and payload capacity computation, the considered evaluation metrics in steganographic applications. The results indicate that our approach achieves a maximum PSNR of 67.8898 decibels with embeddable pixels of 198605. These findings underscore this approach’s efficacy in significantly increasing images data-carrying capacity while preserving visual integrity.