METHOD AND SYSTEM FOR INSERTING AND DETECTING DIGITAL WATERMARK

摘要

PURPOSE: A method and system for inserting and detecting a digital watermark are provided to insert the watermark with a small quantity of calculations for required insertion without deteriorating audio quality. CONSTITUTION: A spreader(140) spreads watermark information to a PN code. A modulator(150) multiplies the spread watermark information by a cosine function. A wavelet transformer(110) wavelet-transforms an audio signal. A scaling factor calculator(120) calculates psychoacoustic model and entropy from the wavelet-transformed audio signal to obtain a scaling factor. An amplifier(160) amplifies the modulated signal by the scaling factor. An adder(170) adds up the amplified modulated signal and the wavelet-transformed audio signal. An inverse wavelet transformer(180) inverse-wavelet-transforms the output signal of the adder.