Robust Semi-blind watermarking using lifting filters

Abstract

두 개의 필터 계수집합으로 리프팅 기법을 이용하여 두 단계 웨이브렛 분해를 한 후 주변의 메디안 값보다 큰 픽셀에 워터마크를 삽입하고 이 위치에 플래그 값을 1로 정한다. 공격을 한후 같은 방법으로 워터마크를 추출하여 플래그 값을 비교하여 저작권을 증명한다. Recently, digital contents can be easily accessed and modified by various digital technology. For protecting copyright or intellectual properties of digital data, digital watermarking technique has attracted considerable. In this paper, we propose a robust watermarking scheme for digital images based on the lifting scheme which provides simple construction of second generation wavelets. The original image is transformed into wavelet domain two sets of lifting filters; one is for usual wavelet filter, the other is for embedding watermarks whose locations are created randomly in a selected wavelet domain with secret key.