A New Steganography Scheme Based on an Index-Color Image

In this paper, we propose a new more efficient steganography technique that can be applied in Internet environment. The new efficient technique can hide from 1 to 8 bits secret data per pixel, and has no distortion if the number of colors does not exceed 128. The proposed scheme first divides the secret data into several parts based on the number of colors in the cover image, and then embed secret data into the cover image, part by part by expanding palettes and modifying indices. Finally, the cover image can be recovered easily without loss. Indeed, numerical experiments indicate that the new technique introduces no distortion to the cover image, in contrast with other schemes that based on index-color, such as EZ Stego. Furthermore, the proposed scheme can be applied to BMP, GIF and PNG image formats which use the index-color technique. Thus, the proposed scheme suits the current Internet environment very well.