A palette-based image steganographic method using colour quantisation

In this paper we propose an efficient data embedding algorithm for palette-based images by quantising similar colours in the palette. Unlike previous algorithms, this method´s rate-distortion behaviour is independent from the embedding message, so that given the length of the embedding message, the distortion on the host image can be determined before embedding. Experiments show that our method outperforms previous methods both in terms of PSNR and visual quality.