Efficient Optical Watermark Using Multiple Phase Wrapping and Real-Valued Functions

다중위상래핑과 실수값 함수를 이용한 효율적인 광 워터마킹

  • Cho, Kyu-Bo (School of Electronical Engineering & Computer Science, Kyungpook Nat'l Univ.) ;
  • Seo, Dong-Hoan (Division of Electrical and Electronics Engineering, Korea Maritime Univ.) ;
  • Lee, Seung-Hee (Department of Esports Game, TaeKyeung Univ.) ;
  • Hong, Jae-Keun (School of Electronical Engineering & Computer Science, Kyungpook Nat'l Univ.)
  • 조규보 (경북대학교 전자전기컴퓨터학부) ;
  • 서동환 (한국해양대학교 전기전자공학부) ;
  • 이승희 (대경대학 e스포츠게임과) ;
  • 홍재근 (경북대학교 전자전기컴퓨터학부)
  • Published : 2009.03.25


In this paper, an efficient optical watermark method using multiple phase wrapping and real-valued decoding key is proposed. In the embedding process, two zero-padded original images placed in two quadrants on input plane are multiplied with two statistically independent random phase patterns and are Fourier transformed, respectively. Two encoded images are obtained by taking the real-valued data from these Fourier transformed images. And then two phase-encoded patterns, used as a hidden image and a decoding key, are generated by the use of multiple phase wrapping from each of the encoded images. A transmitted image is made from the linear superposition of the weighted hidden images and a cover image. In reconstruction process, the mirror reconstructed images can be obtained at all quadrants by the inverse-Fourier transform of the product of the transmitted image and the decoding key. Computer simulation and optical experiment are demonstrated in order to confirm the proposed method.


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