PURPOSE: A water marking method and water mark extraction method in a wavelet area using wavelet conversion and border information are provided to determine an area to insert a watermark by reflecting all shape detection in a energy distribution and a space area in a frequency area. CONSTITUTION: A digital image obtains a wavelet image by converting a multiple wavelet conversion(S10). A first candidate area is selected after calculating energy per unit area by dividing one among high frequency sub band of the wavelet image as a first unit area(S20). A second candidate area is selected after calculating alerting information per unit area by dividing the digital image as a second unit area(S30). Final candidate area is extracted by logically multiplying the first candidate area and the second candidate area(S40). By selecting one among the low frequency sub ban of the wavelet image, a watermark is inserted to an area of a sub band selected by corresponding to the final candidate area(S50). The wavelet image which is substituted as a sub band in which the watermark is inserted is restored(S60).
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