VQ-Based Oriented Image Tamper Proofing Schemes for Digital Grayscale Images

Two VQ-based image-tamper-proofing schemes for digital grayscale images are presented in this paper. The first scheme, which we call Scheme-1, partitions a VQ codebook into two sub-codebooks called the sub-codebook 0 and the sub-codebook 1. The sub-codebook 0 is used to imply embed authentication bit 0, and sub-codebook 1 is used to imply authentication bit 1. Once an intruder has modified the signed image, our Scheme-1 has the ability to detect the locations of the modified places according to the embedded authentication codes. One of the advantages of Scheme-1 is that it can tolerate reasonable image processing such as JPEG compression and the like. On the other hand, in order to enhance the image quality of Scheme-1, the concept of multiple codebooks is added in Scheme-2. Both of the schemes require no presence of the original image when they perform the verification procedure. Experimental results show that the image quality of Scheme-1 and Scheme-2 is acceptable without producing noticeable distortion. Besides, our analyses will also show that the robustness and the security of Scheme-1 and Scheme-2 are quite established.