Lossless Watermarking for Image Tamper Detection and Reconstruction

Abstract

A new image tamper detection and reconstruction scheme based on lossless watermarking is proposed. To achieve tamper detection and image reconstruction, the reconstruction information of an image is self-embedded by block-wise difference expansion lossless watermarking algorithm. The reconstruction information consists of recovery code, parity-check code, and reverse side information. The parity-check code is used for tamper detection. Image blocks detected as tampered can be recovered effectively from the corresponding recovery code stored in another block. If the corresponding recovery code is also tampered, image inpainting technique is applied to improve the quality of reconstructed image. In addition, since the reconstructed information is embedded by lossless watermarking, all of the non-tampered image blocks can be restored to the original . , i.e., the distortion caused by embedding of the reconstruction information can be removed completely. Experimental results demonstrate that not only the tampered image blocks can be effectively detected and reconstructed but also the quality of reconstructed image will be better than that of watermarked image.