A data hiding scheme based on anti-gray coding

Data hiding schemes are always important issues in computing. For image applications, secret messages are hidden in the spatial domain or frequency domain. In this paper, a novel data-hiding scheme is introduced, which embeds data in vector quantization (VQ) indices. This means that this scheme comes with the advantage of compressing stego images into a smaller size, unlike other data-hiding schemes. In other schemes, compression is a kind of attack to damage the secret message in stego images. In addition, with the proposed scheme, there is no need to refer to the host image in extracting secret messages from the stego image. The image quality of stego images depends on the VQ codebook. The hiding procedure does not affect the image quality. These advantages result from the anti-gray coding concept in the index assignment procedure. From the analyses of the chosen host images and indexing codevectors for 9 typical images, we see that the proposed data hiding scheme is indeed applicable.