Secret data delivery is an important research field in recent years because of the development of advanced information technique. (2, 3) threshold secret sharing scheme not only achieves the goal of secret data delivery but also increases security. The proposed scheme uses one cover image to generate three shadow images for carrying secret data and deliver it to a receiver over the computer networks. The secret data can be extracted from shadow images by using the proposed secret extracting procedure cooperating with at least two shadow images. Moreover, the cover image can be fully reconstructed after secret data has been extracted. From the experimental results, the visual quality of shadow images generated by the proposed scheme is higher than 34 dB in average.
