Reversible data hiding for JPEG images based on pairwise nonzero AC coefficient expansion

• Published in: Signal processing Vol. 171; p. 107476
• Main Authors: Li, Nan, Huang, Fangjun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2020
• Subjects: block and frequency selection; JPEG; pairwise nonzero AC coefficient expansion (pairwise NACE); reversible data hiding (RDH); block and frequency selection; JPEG; reversible data hiding (RDH); pairwise nonzero AC coefficient expansion (pairwise NACE)
• ISSN: 0165-1684; 1872-7557
• DOI: 10.1016/j.sigpro.2020.107476

•A new JPEG RDH scheme based on pairwise nonzero AC coefficient expansion is proposed.•A new strategy for pairing the nonzero AC coefficients and constructing a sharp 2D histogram is proposed.•An efficient reversible 2D mapping is carefully designed for data embedding.•A block and frequency selection strategy is utilized for improving the embedding performance.•Proposed scheme outperforms some state-of-the-art works both in visual quality and file size preservation. JPEG (Joint Photographic Experts Group) is the most common format in our daily life for storing and transmitting photographic images. Reversible data hiding (RDH) for JPEG images currently is one of the hotspots in the field of data hiding. However, different from RDH in uncompressed images, any modification in the compressed domain may produce distinct visual distortion and significantly increase the file size of the marked image. In this paper, a new JPEG RDH scheme based on pairwise nonzero AC coefficient expansion (pairwise NACE) is proposed. Firstly, by taking every two adjacent nonzero alternating current (AC) coefficients together to generate the nonzero-AC-coefficient pairs (NACPs), a sharp two-dimensional (2D) histogram can be constructed. Then a new reversible 2D mapping is carefully designed, and data are embedded based on the modification of these NACPs according to the mapping. Furthermore, an adaptive embedding strategy based on block and DCT frequency selection is proposed in order to preserve the visual quality and reduce the file size increase of the marked JPEG image. Experimental results demonstrate that our proposed method can achieve better performance both in visual quality and file size preservation compared to the previous works.