Among the many techniques available for informationconcealment, those based on spread spectrummodulationshave proven to yield improved results when robustness against attack is at a premium. In this paper, we propose a new spread spectrum-based watermarking procedure that combines spaceand frequencymarksto providegoodrobustness properties against both spatial (affine) and transform-based compression attacks, without needing the original image as a reference (blind detection). It provides a mechanism for N-bit concealment and also improves the detection-ofpresence process by gathering all watermark energy into a single value (sufficient statistic for detection). The recovery of every single bit is also improved by taking into account the so-called "watermark-print" or "waterprint" instead of looking at a single correlation value. It additionally provides the means to recover synchronizationunder affine transformationsin the blind detection scenario. These characteri...
Angel Navia-Vázquez, I. Mora-Jiménez