The present invention provides a watermarking method, apparatus and system for
embedding additive information in digital data, in which one frame is defined as
including samples extracted from digital data and a current frame is defined as
a frame that is overlapped by samples of a preceding frame. Included are: a transformation
unit, for multiplying a frame extracted from digital data by a window function
and performing a Fourier transform on the digital data; an embedding unit, for
employing bit information and a frequency band to change the amplitude of the frequency
component in the digital data; a transformation unit, for performing an inverse
Fourier transform to return the frequency component whose amplitude has been changed
by the frequency domain embedding unit; and a frame generator, for multiplying
the time domain signal and superimposing overlapped frames to generate a frame
wherein the additive information is embedded.
