• Title/Summary/Keyword: noise visibility function

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Adaptive Watermark Detection Algorithm Using Perceptual Model and Statistical Decision Method Based on Multiwavelet Transform

  • Hwang Eui-Chang;Kim Dong Kyue;Moon Kwang-Seok;Kwon Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.8 no.6
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    • pp.783-789
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    • 2005
  • This paper is proposed a watermarking technique for copyright protection of multimedia contents. We proposed adaptive watermark detection algorithm using stochastic perceptual model and statistical decision method in DMWT(discrete multi wavelet transform) domain. The stochastic perceptual model calculates NVF(noise visibility function) based on statistical characteristic in the DMWT. Watermark detection algorithm used the likelihood ratio depend on Bayes' decision theory by reliable detection measure and Neyman-Pearson criterion. To reduce visual artifact of image, in this paper, adaptively decide the embedding number of watermark based on DMWT, and then the watermark embedding strength differently at edge and texture region and flat region embedded when watermark embedding minimize distortion of image. In experiment results, the proposed statistical decision method based on multiwavelet domain could decide watermark detection.

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Adaptive Image Watermark Embedding Using a Stationary GG Modeling within Multiresolution (다해상도를 갖는 정상상태 GG 모델을 이용한 적응 워터마크 은닉 기술)

  • 김현천;권기룡;김종진
    • Proceedings of the Korea Multimedia Society Conference
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    • 2002.05d
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    • pp.886-889
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    • 2002
  • 본 논문에서는 보다 강인한 워터마크의 은닉을 위하여 웨이브릿 변환영역에서 정상상태 일반화 가우스(generalized Gaussian) 모델을 이용한 적응 워터마크 은닉 기술을 제안한다. 워터마크는 고주파 영역에서 연속 부대역 양자화(successive subband quantization: SSQ)를 이용하여 다해상도 영상의 웨이브릿 계수 중에서 시각적 중요 계수(perceptually significant coefficients: PSC)에만 은닉한다. 워터마크를 은닉하기 위한 지각모델은 정상상태의 통계적 특성을 이용한다. 이것은 국부영상 특성을 갖는 NVF(noise visibility function) 함수에 의하여 계산되어진다. 은닉모델은 다해상도내의 각 서브밴드별 분산과 형상계수(shape parameter)를 사용한다. 여러 가지 공격 실험결과 우수한 비가시성과 강인성을 확인하였다.

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Adaptive Digital Watermarking Based on Wavelet Transform Using Successive Subband Quantization and Perceptual Model

  • Kim, Ju-Young;Kwon, Seong-geun;Hwang, Hee-Chul;Kwon, Ki-Ryong;Kim, Duk-Gyoo
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1240-1243
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    • 2002
  • In this paper, we propose an adaptive digital image watermarking algorithm using successive subband quantization (SSQ) and perceptual model based on wavelet domain. The watermark is embedded into the perceptually significant coefficients (PSCs) of image. The PSCs in the baseband are selected according to the amplitude of the coefficients and the high frequency subbands are selected by SSQ. To embed the watermark, we use perceptual model. The perceptual model is based on the computation of the noise visibility function (NVF) and embed at the texture and edge region stronger embedded watermarks.

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Adaptive Watermarking Using Successive Subband Quantization and Perceptual Model Based on Mukiwavelet Transform (멀티웨이브릿 변환 기반에서 연속 부대역 양자화 및 지각 모델을 이용한 적응 워터마킹 기술)

  • 권기룡;강균호;조영웅;문광석;이준재
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.121-124
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    • 2002
  • This paper presents an adaptive digital image watermarking scheme that uses successive subband quantization (SSQ) and perceptual modeling. Our approach performs a multiwavelet transform to determine the local image properties optimal and the watermark embedding location. The multiwavelet used in this paper is the DGHM multiwavelet with approximation order 2 to reduce artifacts in the reconstructed image. A watermark is embedded into the perceptually significant coefficients (PSC) of the image in each subband. The PSCs in high frequency subbands are selected by setting the thresholds to one half of the largest coefficient in each subband. After the PSCs in each subband are selected, a perceptual model is combined with a stochastic approach based on the noise visibility function to produce the final watermark.

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Digital Image Watermarking Using Perceptually Tuned Characteristic and Stochastic Model Based on Multiwavelet Transform (멀티웨이브릿변환 영역에서 지각적 동조 특성과 통계적 모델을 이용한 디지털 영상 워터마킹)

  • 황의창;윤재식;유상욱;문광석;박남천;권기룡
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2003.06a
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    • pp.54-57
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    • 2003
  • 본 논문에서는 멀티웨이브릿 변환영역에서 통계적 모델과 지각적 동조특성을 이용한 적응적 디지털 워터마킹 기법을 제안한다. 워터마크는 4레벨로 분해된 멀티웨이브릿 변환영역에서 최저주파 영역과 최고주파 대역들을 제외한 중간 및 고주파 영역에, 인간 시각 시스템(human visual model BWS)을 이용한 JND(just noticeable difference) 특성과 NVF(noise visibility function)를 이용한 통계적 특성을 기반으로 정상상태 가우시안 모델과 비정상상태 가우시안 모델에 따라 지각적 동조 특성을 이용하여 적응적으로 삽입된다. 실험 결과 제안한 방법에서 에지나 텍스쳐 영역에 더 강하게 삽입할 수 있었고, 평탄영역에서 보다 적응적으로 은닉할 수 있었으며 정상상태 가우시안 모델에서 지각적 동조특성을 이용한 방법이 더 우수한 비가시성과 강인성을 확인하였다.

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Adaptive Data Hiding Using Perceptually Tuned Model Based on Multiwavelet Transform (멀티웨이브릿변환 기반에서 지각적 동조 모델을 이용한 적응 데이터 은닉)

  • 유상욱;윤재식;장봉주;조영웅;문광석;권기룡
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.334-337
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    • 2003
  • 본 논문에서는 멀티웨이브릿 변환영역에서 스토케스틱 모델과 지각적 동조특성을 이용한 적응 디지털 워터마크 은닉 방법을 제안한다. 워터마크는 4레벨로 분해된 멀티웨이브릿 변환영역에서 최저주파 영역과 최고주파 대역들을 제외한 중간 및 고주파 영역에, 인간 시각 시스템(human visual model : HVS)을 이용한 JND(just noticeable difference) 특성과 NVF(noise visibility function)를 이용한 통계적 특성을 기반으로 정상상태 가우시안 모델에 따라 지각적 동조 특성을 이용하여 적응적으로 은닉된다. 실험 결과 제안한 방법에서 에지나 텍스쳐 영역에 더 강하게 삽입할 수 있었고, 평탄영역에서 보다 적응적으로 은닉할 수 있었으므로 우수한 비가시성과 강인성을 확인하였다

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Content Adaptive Watermarkding Using a Stochastic Visual Model Based on Multiwavelet Transform

  • Kwon, Ki-Ryong;Kang, Kyun-Ho;Kwon, Seong-Geun;Moon, Kwang-Seok;Lee, Joon-Jae
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1511-1514
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    • 2002
  • This paper presents content adaptive image watermark embedding using stochastic visual model based on multiwavelet transform. To embedding watermark, the original image is decomposed into 4 levels using a discrete multiwavelet transform, then a watermark is embedded into the JND(just noticeable differences) of the image each subband. The perceptual model is applied with a stochastic approach fer watermark embedding. This is based on the computation of a NVF(noise visibility function) that have local image properties. The perceptual model with content adaptive watermarking algorithm embed at the texture and edge region for more strongly embedded watermark by the JND. This method uses stationary Generalized Gaussian model characteristic because watermark has noise properties. The experiment results of simulation of the proposed watermark embedding method using stochastic visual model based on multiwavelet transform techniques was found to be excellent invisibility and robustness.

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Adaptive Digital Watermarking with Perceptually Tuned Characteristic Based on Wavelet Transform (웨이브릿 변환영역에서 지각적 동조특성을 갖는 적응적 디지털 워터마킹)

  • 김현천;장봉주;서용수;김종진
    • Journal of Korea Multimedia Society
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    • v.6 no.6
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    • pp.1008-1014
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    • 2003
  • In this paper, we propose the image retrieval method based on object regions using bidirectional round filter in the wavelet transform domain. A conventional method that includes unnecessary background information reduce retrieval efficiency, because of the extraction of feature vectors from the whole region of subband. On proposed method, it extracts accurate feature vectors and keep certainly retrieval efficiency in case of reduced feature vectors, because of the extraction of feature vectors from the only extracted object region. Furthermore, it improve retrieval efficiency by removing unnecessary background information. Consequently, the retrieval efficiency is improved with 2.5%∼5.5% values, which have a little chances to vary according to characteristics of image.

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Digital Video Contents Protection based on DRM (DRM 기반의 디지털 비디오 콘텐츠 보호)

  • Boo, Hee-Hyung;Lee, Wu-Ju;Bae, Ho-Young;Lee, Bae-Ho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.05a
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    • pp.827-830
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    • 2005
  • 본 논문은 DRM(Digital Rights Management)의 핵심요소기술인 디지털 비디오 워터마킹 기술에서 암호화 기법을 함께 적용하여 저작권 판별 및 콘텐츠 보호의 두 가지 역할을 수행하는 시스템을 제안하고자 한다. 본 논문에서는 저작권 정보를 공개키 기반의 RSA 암호화 방법으로 암호문을 만든 후 이진화 과정을 수행하여 워터마크 키 정보를 생성하였고, 워터마킹 기법으로는 통계적 모델의 계산 속도가 빠른 NVF(Noise Visibility Function) 방식의 Adaptive Stationary GG(Generalized Gaussian) model[1]의 기법을 사용하였다. 암호문은 사용자 컨트롤러에서 제어가 가능하도록 하여 권한이 부여된 사용자만이 재생이 가능하도록 하였다. 본 논문의 구성은 2장에서 암호화 과정을 설명하고, 3장에서는 기존의 기법과는 다른 통계적 접근의 워터마킹 기법을 적용한 과정을 설명하며, 4장에서는 제안한 방법이 실제 환경에서의 실험 결과를 보여준다. 마지막으로 5장에서는 결론과 개선점을 바탕으로 향후 연구방향을 제시한다. 본 논문에서 제안한 방법은 미래사회 인터넷에서의 올바른 디지털 콘텐츠 사용 문화 정책에 큰 역할을 할 것으로 기대된다.

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Human Visual System based Automatic Underwater Image Enhancement in NSCT domain

  • Zhou, Yan;Li, Qingwu;Huo, Guanying
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.2
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    • pp.837-856
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    • 2016
  • Underwater image enhancement has received considerable attention in last decades, due to the nature of poor visibility and low contrast of underwater images. In this paper, we propose a new automatic underwater image enhancement algorithm, which combines nonsubsampled contourlet transform (NSCT) domain enhancement techniques with the mechanism of the human visual system (HVS). We apply the multiscale retinex algorithm based on the HVS into NSCT domain in order to eliminate the non-uniform illumination, and adopt the threshold denoising technique to suppress underwater noise. Our proposed algorithm incorporates the luminance masking and contrast masking characteristics of the HVS into NSCT domain to yield the new HVS-based NSCT. Moreover, we define two nonlinear mapping functions. The first one is used to manipulate the HVS-based NSCT contrast coefficients to enhance the edges. The second one is a gain function which modifies the lowpass subband coefficients to adjust the global dynamic range. As a result, our algorithm can achieve contrast enhancement, image denoising and edge sharpening automatically and simultaneously. Experimental results illustrate that our proposed algorithm has better enhancement performance than state-of-the-art algorithms both in subjective evaluation and quantitative assessment. In addition, our algorithm can automatically achieve underwater image enhancement without any parameter tuning.