• Title/Summary/Keyword: 웨이블릿 변환

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Linear Scratch Detection and Removal Technique for Old Film Sequences Using Wavelet Shrinkage and Interpolation (고전 영화 복원을 위한 웨이블릿 계수축소와 보간법을 이용한 선형 스크래치 검출 및 제거 기술)

  • Kang, Won-Seok;Lee, Eun-Sung;Kim, Sang-Jin;Paik, Joon-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.5
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    • pp.1-9
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    • 2011
  • This paper presents a novel scratch detection and removal approach for old film images in wavelet-domain. Various scratch detection and removal algorithms have been proposed for past decades. However, accurate scratch detection and removal with a moderate amount of computing effort is still a problem because of trade off between the quality of the film and computational load. For overcoming this problem, we first decompose an input image using a 3-level wavelet transform, and then remove the scratch by shrinking wavelet coefficients using linear interpolation. Experimental results show that the proposed algorithm can efficiently detect and remove the scratch in damaged films, and also be incorporated into old film restoration systems.

Fixed-point Optimization of a QRS complex Detection Algorithm Using Wavelet Transform (웨이블릿을 이용한 QRS complex 검출 알고리즘의 고정 소수점 연산 최적화)

  • Park, Young-chul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.7 no.3
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    • pp.126-131
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    • 2014
  • In this study, QRS complex is detected by Wavelet Transform and it can be worked in 32bit fixed point operation thought optimization. First, ECG signal is passed though band pass filter. Second, it is transformed using one-band combined wavelet function from 3-band wavelet function. Third, it is passed though moving window integral. Finally, QRS complex is detected by decision rule. The proposed algorithm is evaluated using MIT-BIH arrhythmia database. Its all of process make progress 32-bit fixed-point operation and it makes table that high complexity operations like trigonometrical function. The detection algorithm evaluate through computer simulation.

Implementation of Wavelet-based detector of Microcalcifications in Mammogram (맘모그램에서 마이크로캘시피케이션을 검출하기 위한 웨이블릿 검출기의 구현)

  • Han, Hui-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.4
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    • pp.325-334
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    • 2001
  • It is shown that the multiscale prewhitening matched filter for detecting Gaussian objects in Markov noise can be implemented by the undecimated wavelet transform with a biorthogonal spline wavelet. If the object to be detected is Gaussian shaped and its scale coincides with one of those computed by the wavelet transform, and if the background noise is truly Markov, then optimum detection is realized by thresholding the appropriate details image. Our detection algorithm is applied to the digitized mammograms for detecting microcalcifications. However, microcalcifications are not exactly Gaussian shaped and its background noise may not be Markov. In order to campensate for these discrepancy, Hotelling observer is employed, which is applied to feature vectors comprised of 3-octave wavelet coefficients.

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Polaroid Film Defect Detection Using 2D - Continuous Wavelet Transform (2차원 연속 웨이블릿을 이용한 편광 필름 결함 검출)

  • Jung, Chang-Do;Kim, Se-Yun;Joo, Young-Bok;Yun, Byoung-Ju;Choi, Byung-Jae;Park, Kil-Houm
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.6
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    • pp.743-748
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    • 2009
  • In this paper, we propose an effective method to extract background components in automated vision inspection system for polarized film used in TFT LCD display panels. The test image signals are typically composed of three components such as ununiform background, random noises and target defect signals. It is important to analyze the background signal for accurate extraction of defect components. Two dimensional continuous wavelets with first derivative gaussian is used. This methods can be applied for reliable extraction of defect signal by elimination of the background signal from the original image. The proposed method outperforms over conventional FFT methods.

Double Integration of Measured Acceleration Record using the Concept of Modified Wavelet Transform (수정된 웨이블릿 변환 개념을 이용한 계측 가속도 기록의 이중 적분법)

  • 이형진;박정식
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.5
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    • pp.11-17
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    • 2003
  • It is well known that the double integration of measured acceleration records is one of the most difficult signal processing, particularly in the measurements on civil engineering structures, The measured accelerations of civil engineering structures are usually non-stationary and contain non-gaussian low-frequency noises, which can be significant causes of numerical instabilities in double Integration, For the de-noising of this kind of signals, wavelet transform can be very effective because of its inherent processing features for non-stationary signals, In this paper, the de-noising algorithm for the double integration is proposed using the modified wavelet transform, which is extended version of ordinary wavelet transform to process non-gaussian and low-frequency noises, using the median filter concept, The example studies show that the integration can be improved by the proposed method.

Digital Watermarking using Wavelet Packet Transform for Remote Sensing Images (웨이블릿 패킷 변환을 이용한 원격 영상의 워터마킹 기법)

  • 한수영;이두수
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.5
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    • pp.365-370
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    • 2003
  • In this paper, a new watermarking algorithm that based on wavelet packet transform is proposed for remote sensing images, which include many high frequency components. It applies watermark to the overall subband that includes the lowest frequency band. Watermark is embedded on original image after selecting the significant wavelet packet coefficients. For selection of significant coefficients which watermarks is embedded on, zerotree algorithm is applied to wavelet packet coefficients using CPSO (Coefficient Partitioning Scanning Order). From the experimental result, the proposed algorithm shows better invisibility and robustness performance compare with conventional watermarking methods. Especially, it demonstrates better robustness for high image compression in the remote images.

Choice of Wavelet-Thresholds for Denoising image (잡음 제거를 위한 웨이블릿 임계값 결정)

  • Cho, Hyun-Sug;Lee, Hyoung
    • The KIPS Transactions:PartB
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    • v.8B no.6
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    • pp.693-698
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    • 2001
  • Noisy data are often fitted using a smoothing parameter, controlling the importance of two objectives that are opposite to a certain extent. One of these two is smoothness and the other is closeness to the input data. The optimal value of this parameter minimizes the error of the result. This optimum cannot be found exactly, simply because the exact data are unknown. This paper propose the threshold value for noise reduction based on wavelet-thresholding. In the proposed method PSNR results show that the threshold value performs excellently in comparison with conventional methods without knowing the noise variance and volume of signal.

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Data Encryption Technique for Depth-map Contents Security in DWT domain (깊이정보 콘텐츠 보안을 위한 이산 웨이블릿 변환 영역에서의 암호화 기술)

  • Choi, Hyun-Jun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.5
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    • pp.1245-1252
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    • 2013
  • As the usage of digital image contents increase, a security problem for the payed image data or the ones requiring confidentiality is raised. This paper propose a depth-map image contents encryption methodology to hide the depth information. This method is performed on the frequency coefficients in the Wavelet domain. This method, by selecting the level and threshold value for the wavelet transform, encryption at various strengths are possible. The experimental results showed that encrypting only 0.048% of the entire data was enough to hide the constants of the depth-map. The encryption algorithm expected to be used effectively on the researches on encryption and others for image processing.

Content-Based Image Retrieval using Primary Color Information in Wavelet Transform Domain (웨이블릿 변환 영역에서 주컬러 정보를 이용한 내용기반 영상 검색)

  • 하용구;장정동;이태홍
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.11-14
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    • 2001
  • 본 논문은 컬러를 이용한 영상 검색 방법에 관한 것으로 영상 데이터의 효율적인 관리를 위해 먼저 전처리 단계로 웨이블릿 변환을 수행한 후 가장 낮은 저주파 부밴드 영상을 획득한다. 그리고, 변환 후 획득된 영상을 클러스터로 구분한 후, 고유치 및 고유 벡터를 이용하여 특징을 추출하여 색인 정보로 이용하였다. 클러스터링은 영상 화소의 컬러공간 상의 3차원 거리를 클러스터링의 기준으로 삼아 순차 영역 분할(Sequential Clustering) 방법을 적용하였다.

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Video Fingerprinting based on the Temporal Wavelet Transform (시간축 웨이블릿 변환에 의한 비디오 핑거프린팅)

  • 강현호;박지환;이혜주;홍진우
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.11a
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    • pp.36-39
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    • 2003
  • 본 논문에서는 비디오 컨텐츠 내에 소유자와 구매자 정보를 함께 포함하는 핑거프린팅 정보를 삽입하여 불법으로 배포된 핑거프린팅 컨텐츠로부터 배포자가 누구인지를 추적할 수 있는 기법을 보인다. 특히, 문헌[1]에서 제시된 시간축 웨이블릿 변환을 이용하여 핑거프린팅 정보가 삽입될 영역을 분리해 주고, 역 변환을 통해 전 영역의 비디오 프레임에 정보가 삽입되게 된다. 이로 인해 핑거프린팅된 컨텐츠의 상이성을 이용한 기존의 여러 공모공격에도 강인함을 보이고 있다. 또한, 비디오 컨텐츠의 특성상 MPEG2의 압축에도 불법 배포자를 추적할 수 있는 강인함을 보인다.

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