Space/spatial-frequency based image watermarking

An image watermarking procedure in the space/spatial-frequency domain is proposed. Space/spatial-frequency regions to be watermarked are selected by using the two-dimensional spectrogram. In order to provide both the imperceptibility and robustness of the procedure, a watermark is modeled according to the specific characteristics of pixels’ regions. The inversion from the space/spatial-frequency domain is provided by using the concept of space-varying filtering. The correlation based watermark detection is performed in the space/spatial-frequency domain as well. The efficiency of the proposed procedure is tested in the presence of various common signal processing.