ABSTRACT
This chapter introduces different types of image steganographic schemes based on vector quantization (VQ). It discusses the concept of VQ will be introduced first as the background of the steganographic schemes. VQ technique has been extensively and successfully applied for image compression. The purpose of image steganography is different from traditional cryptography emphasis on the available capacity for hiding. The significant is used for VQ codebook generation, and the insignificant one is used for information hiding based on greedy least significant bits substitution. Image steganography can be implemented on the compressed domain of images as well. Under this circumstance, the hiding capacity for secret information is more restricted and the visual quality of cover images may be decreased as compared with those of the techniques applied on the noncompressed domain of images. Information hiding can be further divided into two main branches: steganography and digital watermarking.
