A novel semi-fragile forensic watermarking scheme for remote sensing images

A semi-fragile watermarking scheme for multiple band images is presented. We propose to embed a mark into remote-sensing images applying a tree-structured vector quantization approach to the pixel signatures, instead of processing each band separately. The signature of the multi- or hyperspectral image is used to embed the mark into it in order to detect any significant modification of the original image. The image is segmented into three-dimensional blocks and a tree-structured vector quantizer (TSVQ) is built for each block. These trees are manipulated using an iterative algorithm until the resulting block satisfies a required criterion which establishes the embedded mark. The method is shown to be able to preserve the mark under lossy compression (above a given threshold) but, at the same time, it detects possibly forged blocks and their position in the whole image.