• Title/Summary/Keyword: Digital Watermark

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Embedding DC Digital Watermarking in the DCT (DCT의 DC 계수에 워터마크 삽입하는 디지털 워터마킹)

  • 신용달;권성근
    • Journal of Korea Multimedia Society
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    • v.6 no.6
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    • pp.962-967
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    • 2003
  • In this paper, we proposed DC term embedding digital watermarking in the DCT domain. We computed a 8${\times}$8 block DCT The watermark signal is composed of a random number sequence of length 1000, which obeys normal distribution with zero mean and unit variance N(0,1). We embedded watermark signal in DC term for small watermark signal, the other watermark signal embedded in the largest AC coefficients. Experiment show that the invisibility and robust of the proposed method better than those of the conventional methods.

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Invisible Watermarking Algorithm based on Zerotree Structure (제로트리 구조를 이용한 비가시적인 워티마킹 알고리즘)

  • 박병선;유지상
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.97-100
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    • 2002
  • In this paper, we propose a watermarking technique that embeds a digital watermark into digital images for the proof of owner or copyright protection. Proposed algorithm is based on discrete wavelet transform. Zerotree structure defined by Shapiro's embedded zerotree wavelet(EZW) algorithm is used. In the proposed algorithm, a digital watermark is embedded on only significant wavelet coefficients chosen by QSWT for the robustness of the algorithm. In other words, only the values of significant wavelet coefficients are modified in accordance with the given watermark pattern. We use the relationship among neighboring coefficients when modifying chosen coefficients to keep good image quality. Visual recognizable patterns such as binary images are used as a watermark. The experimental results show that the proposed algorithm has robustness under a variety of attacks such as JPEG compression, sharpening and blurring and also show that it has a better performance in PSNR comparing with other algorithms.

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Development of Digital Watermark Embedding Algorithm using Fourier Series Expansion (푸리에 급수전개를 이용한 워터마크 삽입 알고리즘의 개발)

  • Min, Jun-Yeong;Choe, Jong-Uk
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.6
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    • pp.662-669
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    • 1999
  • Digital watermarking이란 영상이나 비디오, 오디오, 텍스트 등의 저작물에 잘 식별되지 않는 표시를 삽입하여 저작권을 보호하는 방법으로 소유권자의 동의없이 저작물을 배포, 복사되는 것을 방지하는 법이다. 본 논문은 watermark를 삽입하기 위해서 sin과 cos 함수를 이용한 Fourier 급수전개를 이용하였다. 우선 , 원 이미지를 주파수 영역으로 변환한 다음 watermark를 삽입할 위치를 M $\times$Nro의 Random Sequence를 발생하여 결정하였으며, M개의 파형을 가장 직교성이 좋다고 하는 sin 함수와 cos 함수를 이용하여 Fourier 급수전개를 하였다. 이 때, sin과 cos의 n의 고조파 역시 Random Sequence를 발생하여 결정하였다. 제안한 알고리즘은 이와 같이 Fourier 급수전개를 했을 때 각 항의 Fourier 계수를 산출하여 이 Fourier 계수에 watermark를 삽입하였다. 실험 결과 JPEG 압축, Blurring, 노이즈삽입 등의 이미지 왜곡에 대하여 watermark 상관관계가 최소 0.1979에서 최대 0.9732까지의 견고성(robustness)을 보였다.

Fake Iris Image Detection based on Watermark

  • Kim, Man-Ki;Lee, Samuel;Kim, Gye-Young
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.4
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    • pp.33-39
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    • 2018
  • In this paper, we propose a describes how to detect a false iris image by inserting watermark into a iris image. The existing method, which inserts the watermark into the entire iris image to detect a fake iris, has a problem that can evade it by segmenting iris region of an iris image. The purpose of overcoming the problem, this paper proposes a new fake iris detection technique based on digital watermark. It first searches a central point of an iris image, divide the image into blocks with respect to the point. executes Discrete Cosine Transform, inserts watermark into the blocks, and then verifies an iris image using NC(Normalized Correlation). In the experiments, we confirm the robustness for attacks - crop and JPEG.

Coded Watermark Detecting Algorithm using a Blind Detecting Method Without Original Videos (원본 동영상 대조 없이 가능한 Blind 검출 방식의 코드화된 워터마크 검출 알고리즘)

  • Hwang, Seon-Cheol
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.395-400
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    • 2010
  • Digital watermark technologies conceal the information of video contents that presents who is the owner and/or who is the user. In spite of various attempts to insert watermark, trials to mark information of users or buyers into contents have not been successful. It is the reason that the rates of detection is decreased seriously if there are some attacks to the contents such as resizing or bitrate decreasing. In this paper, the algorithm to insert the coded watermarks of users into video contents and to detect them without original contents under attacks will be described.

A Study on Blind Watermarking Technique of Digital Image using 2-Dimensional Empirical Mode Decomposition in Wavelet Domain (웨이블릿 평면에서의 2D-EMD를 이용한 디지털 영상의 블라인드 워터마킹 기술에 관한 연구)

  • Lee, Young-Seock;Kim, Jong-Weon
    • Journal of Internet Computing and Services
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    • v.11 no.2
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    • pp.99-107
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    • 2010
  • In this paper a blind watermarking algorithm for digital image is presented. The proposed method operates in wavelet domain. The watermark is decomposed into 2D-IMFs using BEMD which is the 2-dimensional extension of 1 dimensional empirical mode decomposition. The CDMA based on SS technique is applied to watermark embedding and detection process. In the watermark embedding process, each IMF of watermark is embedded into middle frequency subimages in wavelet domain, so subimages just include partial information about embedded watermark. By characteristics of BEMD, when the partial information of watermark is synthesized, the original watermark is reconstructed. The experimental results show that the proposed watermarking algorithm is imperceptible and moreover is robust against JPEG compression, common image processing distortions.

Digital Watermark Based Error Detection for MPEG-4 Bitstream Error

  • Hiroyuki Okada;Shiitev, Altan-Erdene;Song, Hak-Sop;Gen Fujita;Takao Onoye;Isao Shirakawa
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.152-155
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    • 2002
  • In this paper, a new approach is proposed for the error detection dedicated to MPEG-4 video coding by using the digital watermarking. In the process of encoding, the proposed scheme abstracts the macroblock features of headers, motion vectors, and Discrete Cosine Transform (DCT) coefficients, which are embedded in the quantized DCT coefficients as the digital watermarks. The decoder performs the accurate error detection through the watermark extraction. Simulation results demonstrate that the error detection ability of the proposed approach can be significantly enhanced, and that digital watermark embedding incurs little degradation to the picture quality.

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Hiding Digital Watermark for Increasing Trust in E-Commerce

  • Moon, Ho--Seok;Sohn, Myung--Ho
    • Proceedings of the CALSEC Conference
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    • 2004.02a
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    • pp.223-226
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    • 2004
  • Several studies have shown that the trust is a significant barrier for realizing the potential of e-commerce. Trust is not only a short-term issue but also the most significant long-term barrier for realizing the potentials of e-commerce. Because digital contents which have been used in e-commerce are easy to be duplicated, the enforcement of digital copyright protection is an important issue. Watermarking is a technique for labeling digital pictures by hiding secret information in the image. In this paper, a discrete wavelet transform(DWT) based technique for embedding digital watermark into image is proposed. The performance of the proposed watermarking is robust to a variety of signal distortions, such as JPEG and image processing operations.

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Barcode Pattern Image Watermark Using Triplet (트리플릿을 이용한 바코드 패턴 이미지 워터마크)

  • Park, Byung-Su;Chu, Hyung-Suk;An, Chong-Koo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.12
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    • pp.2330-2335
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    • 2008
  • In this paper, we proposed a robust watermark scheme for image based on the discrete wavelet transform. In the first, we use the triplet method for embedding and extraction of watermark. Triplet method uses relationship among the discrete wavelet coefficients at the same position in the three detail subband of image. In the second, we use barcode Pattern Image for watermark scheme. By using barcode Pattern Images, a user is able to make many kinds of own watermark. In the third, the proposed method for image watermark provides the invisiblility which the other user can not discriminate watermark from watermarked image. The advantage of the proposed method is visibility when we extracted watermark from the image. The corresponding experimental results show that the proposed method has performance of a robustness from the noise attack.

A Study on the Selection of the Optimal Region for Digital Watermarking in the Frequency Domain (주파수 영역에서의 최적의 워터마크 삽입영역 선정에 대한 연구)

  • Oh, Jae-Ho;Kim, Sun-Hyung;Lim, Hae-Jin
    • The KIPS Transactions:PartB
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    • v.9B no.4
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    • pp.459-464
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    • 2002
  • In this paper, we propose a private digital watermarking method based on a wavelet transform to protect digital contents copyrights. We find out the optimal watermark insertion region and the optimal amount of watermark in order to satisfy robustness and imperceptibility against various attacks such as noise, compression, collusion, clipping, scaling to transfer the contents safely. Through this experiment, we could find out the adequate location of watermark insertion and proper amount of watermark, and transfer the watermarked image safely.