In this paper we propose a method that analyzes attack patterns and extracts watermark after restoring the watermarked image from the geometric attacks. The proposed algorithm consists of a spatial-domain key insertion part for attack analysis and a frequency-domain watermark insertion part using discrete wavelet transform. With the spatial-domain key extracted from the damaged image, the proposed algorithm analyzes distortion and finds the attack pattern. After restoring the damaged image, the algorithm extracts the embedded watermark. By using both spatial domain key and frequency domain watermark, the proposed algorithm can achieve robust watermark extraction against geometrical attacks and image compressions such as JPEG.
['Dongeun Lee', 'Taekyung Kim', 'Seongwon Lee', 'Joonki Paik']
A robust watermarking algorithm using attack pattern analysis