Abstract: JPEG image compression algorithm can provide users with good compression performance and improve the quality of image file reconstruction. It has a wide range of use value in the field of image and video processing. This paper proposes a feasible and effective method of reversible information hiding for JPEG image. In this scheme, the quantized DCT coefficients of all 8 × 8 sub blocks in JPEG image are rearranged into a new matrix, with the coefficient values of each block listed vertically and at the same frequency listed horizontally. The coefficients at the same frequency are simulated to embed bits, and the coefficients at the frequency with small distortion are preferentially selected to embed information until the secret bitstream information is embedded, and the invalid bitstream expansion is reduced according to the decoding matrix when embedding the secret information. Experimental results show that the method can achieve better visual quality and less image bitstream expansion under the same bitstream embedding.

Key words: Joint Photographic Experts Group (JPEG), DCT coefficient, reversible hiding algorithm