Secret image communication scheme based on vector quantisation

A novel secret image communication scheme capable of delivering several images by a small cover medium is proposed. To reduce the volume of secret images to be delivered, a codebook is generated and the secret images are compressed based on the VQ encoding system. The compressed message is then embedded into the VQ codebook by an adaptive least-significant-bits modification technique. Finally, the slightly modified codebook is encrypted into a meaningless data stream by the DES cryptosystem for security.