Reversible Data Hiding in Encrypted Images With Hybrid Encoding and Bitstream Rearrangement

Reversible data hiding in encrypted images (RDHEI) has become increasingly important for cloud storage and privacy protection. However, striking a balance between embedding capacity and security remains a significant challenge for researchers. This paper proposes a hybrid Encoding RDHEI scheme that combines custom mapping embedding (CME) and high bit-plane replacement (HBR) methods. By employing a hybrid encoding technique that encodes prediction errors (PEs) of different sizes, the proposed scheme significantly improves the number of embeddable pixels. Unlike existing RDHEI schemes, the proposed scheme embeds label information into a reserved space during the preprocessing and then encrypts it, thereby offering enhanced security during image transmission. Experimental results and analysis demonstrate that our scheme outperforms similar existing schemes in terms of embedding performance, visual quality, stability, and computational complexity. Our proposed scheme achieves a superior performance in a multi-metric evaluation.