Chaotic watermarks for embedding in the spatial digital image domain

Binary (bi-valued) digital signals, which are suitable watermarks for digital images are presented. They are generated by using chaotic dynamical systems that provide sufficient watermark complexity and controlled lowpass characteristics. Watermark detection is performed without resorting to the original image and its reliability is studied. Efficient robustness under lossy compression, lowpass filtering and other image processing can be achieved. Possible watermark detection after geometrical transformations is discussed.