Sharing and hiding a secret image in color palette images with authentication

Existing secret image sharing (SIS) schemes with steganography and authentication are only suitable for uncompressed grayscale images. To make it more practical, a scheme for sharing and hiding a secret image in color palette images with authentication is proposed in this paper. Three commonly used system color palettes are considered. In sharing phase, a secret image is encoded into shared bits by polynomial based SIS. The shared bits are concealed into the color palette cover image to form the stego images. Meanwhile, the authentication parity bits are generated and embedded as well. Two embedding strategies are developed for the color palette images. In authentication and recovery phase, the integrity of each stego image is verified. Then, the secret image are reconstructed by sufficient authentic stego images. Experimental results are demonstrated to show the effectiveness and merits of the proposed scheme.