A suitable image hiding scheme for JPEG images

An image hiding scheme suitable for JPEG compressed images is proposed in this article. The goal of this scheme is to obscurely deliver some secret images via a JPEG image file. Secret images are first encoded into binary indexes by vector quantization. Then, these indexes are embedded into the JPEG file of a cover image by modifying its quantized coefficients and quantization factors in an invertible way. The stego-file keeps the JPEG syntax, which can be displayed by any standard JPEG decoder, without noticeable distortion. A legal receiver with the key can completely extract the secret images and restore the original JPEG image file at the same time. Simulation results demonstrate that the proposed scheme is practicable.