Abstract: Reversible data hiding technology for JPEG images has been widely used.In order to improve the embedding capacity and embedding efficiency of JPEG images in the reversible data hiding process, this paper proposed a reversible data hiding technology based on frequency selective expansion.Firstly, the original image was quantized to generate several DCT blocks, then the DCT blocks were divided into two types to select different embedding positions for embedding based on whether the block contains ±3 and ±4 AC coefficient values.Finally, the embedding distortion of each position in the block were calculated according to the frequency selection strategy.The embedding position was selected and the secret data was embedded according to the ordered frequency of embedded distortion.The experimental results show that the proposed algorithm expands the embedding capacity and reduces the file increase.

Key words: JPEG image, reversible data hiding, AC coefficient, histogram shifting, frequency selection