A New High Capacity Separable Reversible Data Hiding in Encrypted Images Based on Block Selection and Block-Level Encryption

Reversible data hiding in encrypted image (RDHEI) is a technology that can simultaneously implement privacy protection and reversible information hiding. For RDHEI, the main problem is the conflict between embedding capacity and real reversibility. In this paper, to solve such a conflict, a new block-level image encryption method is proposed to fulfill privacy protection while preserving the spatial correlation of pixels inside pixel block. On this basis, a new reversible data hiding method based on block selection is also proposed. Specifically, pixel blocks are classified into embeddable block (EB) and non-embeddable block (NEB). Then, additional data is embedded into only EBs and the position file locating EB is also embedded using a new self-embedding method. Experimental results demonstrate that the proposed method not only achieves high embedding capacity, but also guarantees lossless data extraction and perfect image recovery.