In the recent years, with the rapid development of the network multimedia systems, data hiding and digital watermarking techniques have become a feasible solution to copyright protection and data authentication. In this paper, we present a new data hiding scheme for still images. The technique is based on embedding information in the transform domain; the DFT coefficients of the original image are modified to embed information bits. Taking the symmetric property of DFT coefficients into consideration, our scheme makes a tradeoff between imperceptibility and embedding capacity, and achieves a higher data embedding rate than most of the current transform domain embedding methods. Furthermore, not only gray images but also color ones can be used as cover images for covert communications. The hidden information can be either an image or a text. The experiment result shows good performance and prospect of our technique.