• Title/Summary/Keyword: Haar transform

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Inverse-Orthogonal Jacket-Haar and DCT Transform (Inverse-Orthogonal Jacket-Haar, DCT 변환)

  • Park, Ju Yong;Khan, Md. Hashem Ali;Kim, Jeong Su;Lee, Moon Ho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.9
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    • pp.30-40
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    • 2014
  • As the Hadamard transform can be generalized into the Jacket transform, in this paper, we generalize the Haar transform into the Jacket-Haar transform. The entries of the Jacket-Haar transform are 0 and ${\pm}2^k$. Compared with the original Haar transform, the basis of the Jacket-Haar transform is general and more suitable for signal processing. As an application, we present the DCT-II(discrete cosine transform-II) based on $2{\times}2$ Hadamard matrix and HWT(Haar Wavelete transform) based on $2{\times}2$ Haar matrix, analysis the performances of them and estimate them via the Lenna image simulation.

Medical Image Enhancement Using an Adaptive Weight and Threshold Values (적응적 가중치와 문턱치를 이용한 의료영상의 화질 향상)

  • Kim, Seung-Jong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.5
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    • pp.205-211
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    • 2012
  • By using an adaptive threshold and weight based on the wavelet transform and Haar transform, a novel image enhancement algorithm is proposed. First, a medical image was decomposed with wavelet transform and all high-frequency sub-images were decomposed with Haar transform. Secondly, noise in the frequency domain was reduced by the proposed soft-threshold method. Thirdly, high-frequency coefficients were enhanced by the proposed weight values in different sub-images. Then, the enhanced image was obtained through the inverse Haar transform and wavelet transform. But the pixel range of the enhanced image is narrower than a normal image. Lastly, the image's histogram was stretched by nonlinear histogram equalization. Experiments showed that the proposed method can be not only enhance an image's details but can also preserve its edge features effectively.

New Approach to the Analysis of Linear Systems Via Local Rationalized Haar Transform (미소구간 유리하알변환에 의한 선형계의 해석을 위한 새로운 접근방법)

  • Kim, Jin-Tae;Ahn , Doo-Soo
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.6
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    • pp.228-234
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    • 2002
  • This paper proposes a real-time application of rationalized Haar transform which is based on the local rationalized Haar transform, local operational matrix and local delay operational matrix. This approach let a general sampling time be used by introducing a scaling factor. In the existing method of orthogonal functions, a major disadvantage is that process signals need to be recorded prior to obtaining their expansions. This paper proposes a novel method of rationalized Haar transform to overcome this shortcoming. And the proposed method is suitable for the analysis of linear systems. The proposed method is expected to the applicable to the adaptive control which demanded to the real-time applications.

The Design of Robust MRAC via Haar Functions (하알함수를 이용한 Robust MRAC 설계)

  • Kim, Jin-Tae;Choi, Soo-Young;Jung, Joon-Hong;Lee, Han-Seok;Lee, Myung-Kyu;Ahn, Doo-Soo
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2129-2131
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    • 2002
  • This paper proposes a real-time application of rationalized Haar transform which is based on the rationalized Haar transform, operational matrix and rationalized Haar function's differential operation. In the existing method of orthogonal functions, a major disadvantage is that process signals need to be recorded prior to obtaining their expansions. This paper proposes a novel method of rationalized Haar transform to overcome this shortcoming. And the proposed method apply to the robust MRAC systems.

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Study of the Haar Wavelet Feature Detector for Image Retrieval (이미지 검색을 위한 Haar 웨이블릿 특징 검출자에 대한 연구)

  • Peng, Shao-Hu;Kim, Hyun-Soo;Muzzammil, Khairul;Kim, Deok-Hwan
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.1
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    • pp.160-170
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    • 2010
  • This paper proposes a Haar Wavelet Feature Detector (HWFD) based on the Haar wavelet transform and average box filter. By decomposing the original image using the Haar wavelet transform, the proposed detector obtains the variance information of the image, making it possible to extract more distinctive features from the original image. For detection of interest points that represent the regions whose variance is the highest among their neighbor regions, we apply the average box filter to evaluate the local variance information and use the integral image technique for fast computation. Due to utilization of the Haar wavelet transform and the average box filter, the proposed detector is robust to illumination change, scale change, and rotation of the image. Experimental results show that even though the proposed method detects fewer interest points, it achieves higher repeatability, higher efficiency and higher matching accuracy compared with the DoG detector and Harris corner detector.

CUDA 기반 병렬 Haar Transform 고찰

  • Lee, Sang-Il;Park, Neung-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.11a
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    • pp.249-250
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    • 2009
  • 음향 신호 이미지 처리, human vision 등의 분야에서 널리 쓰이는 wavelet transform의 가장 간단한 형태인 one-dimension haar wavelet transform을 CUDA로 구현하고 hardware 특성을 살린 optimizing을 함으로써 Data-parallelism의 성능과 CUDA memory architecture의 상관 관계를 살펴본다.

An Evaluation of Reversible Data Embedding Algorithm using Haar Wavelet Transform (Haar 웨이블릿 변환을 이용한 가역적 데이터 삽입 알고리즘의 성능 평가)

  • 오인정;김민수;박하중;정현열;정호열
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2003.06a
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    • pp.34-37
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    • 2003
  • 본 논문에서는 가역변환 (reversible transform)에 기반을 둔 가역 워터마킹 기법에 관해 기술한다. 워터마크를 삽입한 후 원본 데이터에 영구적으로 남아있는 기존의 워터마킹 기법과는 달리 가역 워터마킹 기법의 경우, 컨텐츠의 인증이 이루어진 후 삽입되었던 워터마크 신호를 컨텐츠로부터 제거함으로써, 원 영상을 화소단위로 무손실 복원할 수 있는 특징이 있다. 본 논문에서는 가역 변환인 Haar 웨이블릿 변환(Haar Wavelet Transform) 이용하여 원 영상을 변환한 후 웨이블릿 계수를 이용하여 워터마크를 삽입 및 추출한다. 이러한 가역워터마킹 기법은 판사 목적의 영상 혹은 의료영상과 같은 민감한 영상신호처리가 요구되는 분야로 응용될 수 있을 것이다.

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An application of wavelet transform toward noisy NMR peak suppression

  • Kim, Daesung;Kim, Dai-Gyoung
    • Journal of the Korean Magnetic Resonance Society
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    • v.6 no.1
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    • pp.12-19
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    • 2002
  • A shift-averaged Haar wavelet transform was introduced as a new and excellent tool to distinguish real peaks from the noise contaminated NMR signals. It is based on Haar wavelet transform and translation-invariant denoising process. Donoho's universal threshold was newly introduced to the shift-averaged Haar wavelet transform for the purpose of automated noise suppression, and was quantitatively compared with the conventional uniform threshold method in terms or threshold and signal to noise ratio (SNR). New algorithm was combined with a routine to suppress a large solvent peak by singular value decomposition (SVD). Combined algorithm was applied to the real spectrum that containing large solvent peak.

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Performance Improvement of Aerial Images Taken by UAV Using Daubechies Stationary Wavelet (Daubechies 정상 웨이블릿을 이용한 무인항공기 촬영 영상 성능 개선)

  • Kim, Sung-Hoon;Hong, Gyo-Young
    • Journal of Advanced Navigation Technology
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    • v.20 no.6
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    • pp.539-543
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    • 2016
  • In this paper, we study the technique to improve the performance of the aerial images taken by UAV using daubechies stationary wavelet transform. When aerial images taken by UAV were damaged by gaussian noise very commonly applied, the experiment for image performance improvement was performed. It was known that stationary wavelet transform is the transferring solution to the problem occurred by down sampling from DWT also more efficient to remove noise than DWT. Also haar wavelet is discontinuous function so not efficient for smooth signal and image processing. Therefore, this study is confirmed that the noise can be removed by daubechies stationary wavelet and the performance is improved by haar stationary wavelet.