DEVICE OF INSERTING AUDIO WATERMARK AND METHOD THEREOF AND DETECTION DEVICE THEREOF AND METHOD THEREOF

摘要

PURPOSE: A device of inserting an audio watermark is provided to perform a WT(Wavelet Transform) while inserting a watermark, and to detect the watermark without original audio data, thereby inserting the watermark in real time and improving security. CONSTITUTION: A watermark generator(10) generates a watermark signal, and band-spreads the watermark signal by using a PN(Pseudo Noise) signal. A WT unit(30) wavelet-transforms an original audio signal to separate the signal into a low frequency band and a high frequency band, and calculates entropy by WT. A modulator(20) modulates the band-spread watermark signal by using a predetermined frequency, and controls a gain of the modulated watermark signal by using the entropy. An IWT(Inverse Wavelet Transform) unit(40) inserts the gain-controlled watermark signal into the low frequency band, and performs an IWT process for the watermark signal of the low frequency band and an audio signal of the high frequency band, then outputs an audio signal inserted with an watermark.