An adaptive image authentication scheme for vector quantization compressed image

Abstract

This paper proposes an image authentication scheme which detects illegal modifications for image vector quantization (VQ). In the proposed scheme, the index table is divided into non-overlapping index blocks. The authentication data is generated by using the pseudo random sequence. Our scheme can adaptively determine both the size of the authentication data and the number of the indices in each index block. Then, the selected indices are used to embed the secret data to generate the embedded image. To authenticate the given VQ compressed image, two sets of the authentication data are needed to perform the tamper detection process. One set is generated by using the pseudo random number sequence. The other set is extracted from the compressed image. The experimental results demonstrate that the proposed scheme achieves acceptable image quality of the embedded image while keeping good detecting accuracy.