A Discrete Fourier Transform watermark for use with digital images/video.
A Y component of a Y, U(Cb), V(Cr) digital data stream representing color
components of digital video is extracted as the digital data for
embedding the watermark. The digital data is then scaled to a standard
size. A Discrete Fourier Transform (DFT) is performed on the digital
data, and a magnitude domain of the Discrete Fourier Transform is
computed. The watermark is embedded into selected frequency bands of the
computed magnitude domain of the Discrete Fourier Transform, thereby
creating a watermarked magnitude domain. The selected frequency bands
comprise one or more middle frequency bands, and the middle frequency
bands comprise a band of circular rings of the magnitude domain. An
inverse Discrete Fourier Transform is performed on the watermarked
magnitude domain to reconstruct the digital data with the embedded
watermark.