• Title/Summary/Keyword: DWT (Discrete Wavelet Transform)

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Disease Region Feature Extraction of Medical Image using Wavelet (Wavelet에 의한 의용영상의 병소부위 특징추출)

  • 이상복;이주신
    • Journal of the Korea Society of Computer and Information
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    • v.3 no.3
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    • pp.73-81
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    • 1998
  • In this paper suggest for methods disease region feature extraction of medical image using wavelet. In the preprocessing, the shape informations of medical image are selected by performing the discrete wavelet transform(DWT) with four level coefficient matrix. In this approach, based on the characteristics of the coefficient matrix, 96 feature parameters are calculated as follows: Firstly. obtaining 32 feature parameters which have the characteristics of low frequency from the parameters according to the horizontal high frequency are calculated from the coefficient matrix of horizontal high frequency. In the third place, 16 vertical feature parameters are also calculated using the same kind of procedure with respect to the vertical high frequency. Finally, 32 feature parameters of diagonal high frequency are obtained from the coefficient matrix of diagonal high frequency. Consequently, 96 feature aprameters extracted. Using suggest algorithm in this paper will, implamentation can automatic recognition system, increasing efficiency of picture achieve communication system.

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Application of the 3D Discrete Wavelet Transformation Scheme to Remotely Sensed Image Classification

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.355-363
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    • 2007
  • The 3D DWT(The Three Dimensional Discrete Wavelet Transform) scheme is potentially regarded as useful one on analyzing both spatial and spectral information. Nevertheless, few researchers have attempted to process or classified remotely sensed images using the 3D DWT. This study aims to apply the 3D DWT to the land cover classification of optical and SAR(Synthetic Aperture Radar) images. Then, their results are evaluated quantitatively and compared with the results of traditional classification technique. As the experimental results, the 3D DWT shows superior classification results to conventional techniques, especially dealing with the high-resolution imagery and SAR imagery. It is thought that the 3D DWT scheme can be extended to multi-temporal or multi-sensor image classification.

FUSESHARP: A MULTI-IMAGE FOCUS FUSION METHOD USING DISCRETE WAVELET TRANSFORM AND UNSHARP MASKING

  • GARGI TRIVEDI;RAJESH SANGHAVI
    • Journal of applied mathematics & informatics
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    • v.41 no.5
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    • pp.1115-1128
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    • 2023
  • In this paper, a novel hybrid method for multi-focus image fusion is proposed. The method combines the advantages of wavelet transform-based methods and focus-measure-based methods to achieve an improved fusion result. The input images are first decomposed into different frequency sub-bands using the discrete wavelet transform (DWT). The focus measure of each sub-band is then calculated using the Laplacian of Gaussian (LoG) operator, and the sub-band with the highest focus measure is selected as the focused sub-band. The focused sub-band is sharpened using an unsharp masking filter to preserve the details in the focused part of the image.Finally, the sharpened focused sub-bands from all input images are fused using the maximum intensity fusion method to preserve the important information from all focus images. The proposed method has been evaluated using standard multi focus image fusion datasets and has shown promising results compared to existing methods.

Discrete Wavelet Transform-based SOH Prediction using the Voltage Deviation among the Cells of Li-Ion Battery Pack (배터리 팩의 셀간 전압편차를 이용한 이산 웨이블릿 변환(DWT) 기반 SOH 예측방법)

  • Kim, J.H.;Kim, W.J.;Park, J.H.;Park, J.P.
    • Proceedings of the KIPE Conference
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    • 2012.11a
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    • pp.149-150
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    • 2012
  • 본 논문에서는 배터리 팩을 구성하는 셀간의 전압편차를 이용한 이산 웨이블릿 변환(DWT;discrete wavelet transform) 기반 SOH(State-of-health) 예측방법을 소개한다. 충방전 전압은 DWT의 다해상도 분석(MRA;multi-resolution analysis)을 이용한 시간-주파수 분석을 통해 고주파 전압 성분(detail;$D_n$)과 저주파 전압 성분(approximation;$A_n$)으로 추가 분해되어 SOH 예측을 위한 추가정보를 제공한다. 각 성분의 통계처리(표준편차)를 통해 노화 이전과 이후의 성분값을 비교한다. 즉 프레시 배터리팩과 노화된 팩의 표준편차 기반 셀간 불균형을 서로 비교하여 SOH 예측이 가능하다.

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Level Selection of the Multi-Resolution Analysis(MRA) for Optimum Denoising Performance of the Discrete Wavelet Transform(DWT) (이산 웨이블릿 변환(DWT)의 디노이징 최적 성능을 위한 다해상도 분석의 레벨 선택 연구)

  • Whang, J.Y.;Kim, J.H.
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.465-466
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    • 2015
  • 배터리 관리시스템(BMS;battery management system)의 중요 고려요소인 SOC(state-of-charge) 및 SOH(state-of-health)의 전기적 등가회로 모델 기반 고성능 추정의 전제 조건은 배터리 단자전압의 안정된 실험데이터 확보이다. 그러나, 예상치 않은 에러로 인해 배터리 단자전압에 노이즈 성분이 포함될 경우 SOC 및 SOH 추정알고리즘의 성능저하가 우려된다. 이를 위해, 본 논문은 이산 웨이블릿 변환(DWT;discrete wavelet transform)의 다해상도 분석(MRA;multi resolution analysis) 레벨에 따른 디노이징 최적 성능을 소개하고자 한다. 하드 임계화(hard-thresholding) 및 소프트 임계화(soft-thresholding) 기법에 따른 디노이징 성능 차이를 보이고, 각 임계화 기법 적용 시 디노이징 최적 성능을 보이는 레벨을 선택한다.

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An Efficient 2D Discrete Wavelet Transform Filter Design Using Lattice Structure (Lattice 구조를 갖는 효율적인 2차원 이산 웨이블렛 변환 필터 설계)

  • Park, Tae-Geun;Jeong, Seon-Gyeong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.6
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    • pp.59-68
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    • 2002
  • In this paper, we design the two-dimensional Discrete Wavelet Transform (2D DWT) filter that is widely used in various applications such as image compression because it has no blocking effects and relatively high compression rate. The filter that we used here is two-channel four-taps QMF(Quadrature Mirror Filter) Lattice filter with PR (Perfect Reconstruction) property. The proposed DWT architecture, with two consecutive inputs shows an efficient performance with a minimum of such hardware resources as multipliers, adders, and registers due to a simple scheduling. The proposed architecture was verified by the RTL simulation, and utilizes the hardware 100%. Our architecture shows a relatively high performance with a minimum hardware when compared with other approaches. An efficient memory mapping and address generation techniques are introduced and the fixed-point arithmetic analysis for minimizing the PSNR degradation due to quantization is discussed.

The implementation of the color component 2-D DWT Processor for the JPEG 2000 hard-wired encoder (JPEG 2000 Hard-wired Encoder를 위한 칼라 2-D DWT Processor의 구현)

  • Lee, Sung-Mok;Cho, Sung-Dae;Kang, Bong-Soon
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.4
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    • pp.321-328
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    • 2008
  • In this paper, we propose the hardware architecture of two-dimensional discrete wavelet transform (2D DWT) and quantization for using JPEG2000. Color 2-D DWT processor is proposed that is to apply to JPEG 2000 Hard-wired Encoder. JPEG 2000 DWT processor uses the Daubechies' (9,7) bi-orthogonal filter, and we design by minimizing error of the DWT transformer by ${\pm}1$ LSB during compression and decompression. We designed the DWT filters that using by using shift and adder structure instead of multiplier structure which raise the hardware complexity. It is improve the operation speed of filters and reduce the hardware complexity. The proposed system is designed by the hardware description language Verilog-HDL and verified by Synopsys Design Analyzer using TSMC 0.25${\mu}m$ ASIC library.

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Multidimensional uniform cubic lattice vector quantization for wavelet transform coding (웨이브렛변환 영상 부호화를 위한 다차원 큐빅 격자 구조 벡터 양자화)

  • 황재식;이용진;박현욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1515-1522
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    • 1997
  • Several image coding algorithms have been developed for the telecommunication and multimedia systems with high image quality and high compression ratio. In order to achieve low entropy and distortion, the system should pay great cost of computation time and memory. In this paper, the uniform cubic lattice is chosen for Lattice Vector Quantization (LVQ) because of its generic simplicity. As a transform coding, the Discrete Wavelet Transform (DWT) is applied to the images because of its multiresolution property. The proposed algorithm is basically composed of the biorthogonal DWT and the uniform cubic LVQ. The multiresolution property of the DWT is actively used to optimize the entropy and the distortion on the basis of the distortion-rate function. The vector codebooks are also designed to be optimal at each subimage which is analyzed by the biorthogonal DWT. For compression efficiency, the vector codebook has different dimension depending on the variance of subimage. The simulation results show that the performance of the proposed coding mdthod is superior to the others in terms of the computation complexity and the PSNR in the range of entropy below 0.25 bpp.

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DWT Based Multiwatermarking for Authentication and Detection of Image Modification (이미지 인증과 변형 검출을 위한 DWT기반 다중워터마킹)

  • Kang Tae-Hwan;Jang Ho-Hyun;Kim Dong-Seo;Joo Nak-Keun
    • Proceedings of the Korea Contents Association Conference
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    • 2005.11a
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    • pp.480-484
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    • 2005
  • In this paper, the multiwatermarking method to make it possible to the authentication, modification detection and copyright protection of the digital image was proposed. After the original image is transformed by the DWT(Discrete Wavelet Transform), the encrypted watermark information is embedded into the LSB(Least Significant Bit) of LL band on the low frequence domain for authenticating and detecting modified position in the image. And watermark information is embedded by exchanging the wavelet coefficient for the copyright protection. Thereby, we can authenticate the modification and detect the modified location by extracting the values of LSB on the low frequence domain. And we can perceive the copyright information of original image by extracting the embedded watermark on the high frequence domain.

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Hybrid-Watermarking for DWT Based Authentication and Detection of Image Modification (DWT기반 이미지 인증 및 변형 검출을 위한 혼합 워터마킹)

  • Kim Dong-Seo;Joo Nak-Keun;Kang Tae-Hwan
    • The Journal of the Korea Contents Association
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    • v.6 no.1
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    • pp.170-178
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    • 2006
  • In this paper, the hybrid-watermarking method to make it possible to the authentication, modification detection and copyright protection of the digital image was proposed. After the original image is transformed by the DWT(Discrete Wavelet Transform), the encrypted watermark information is embedded into the LSB(Least Significant Bit) of LL band on the low frequence domain for authenticating and detecting modified position in the image. And watermark information is embedded by exchanging the wavelet coefficient for the copyright protection. Thereby, we can authenticate the modification and detect the modified location by extracting the values of LSB on the low frequence domain. And we can perceive the copyright information of original image by extracting the embedded watermark on the high frequence domain.

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