Enhanced Capacity Reversible Data Hiding Based on Pixel Value Ordering in Triple Stego Images

Reversible data hiding (RDH) enables secret data embedding while preserving complete cover image recovery, making it crucial for applications requiring image integrity. The pixel value ordering (PVO) technique used in multi-stego images provides good image quality but often results in low embedding capability. To address these challenges, this paper proposes a high-capacity RDH scheme based on PVO that generates three stego images from a single cover image. The cover image is partitioned into non-overlapping blocks with pixels sorted in ascending order. Four secret bits are embedded into each block’s maximum pixel value, while three additional bits are embedded into the second-largest value when the pixel difference exceeds a predefined threshold. A similar embedding strategy is also applied to the minimum side of the block, including the second-smallest pixel value. This design enables each block to embed up to 14 bits of secret data. Experimental results demonstrate that the proposed method achieves significantly higher embedding capacity and improved visual quality compared to existing triple-stego RDH approaches, advancing the field of reversible steganography.