• 제목/요약/키워드: Multiresolution decomposition

검색결과 23건 처리시간 0.026초

이미지 향상을 위해 공간영역에서 다중해상도를 이용한 개선된 히스토그램 특정화 방법 (An Improved Histogram Specification using Multiresolution in the Spatial Domain for Image Enhancement)

  • 허경무
    • 제어로봇시스템학회논문지
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    • 제20권6호
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    • pp.657-662
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    • 2014
  • Usually, spatial information can be incorporated into histograms by taking histograms of a multiresolution image. For these reasons, many researchers are interested in multiresolution histogram processing. If the relation and sensitivity of the multiresolution images are well combined without loss of information, we can obtain satisfactory results in several fields of image processing including histogram equalization, specification and pattern matching. In this paper, we propose a multiresolution histogram specification method that improves the accuracy of histogram specification. The multiresolution decomposition technique is used in order to overcome the unique feature of a histogram specification affected by a quantization error of a digitalized image. The histogram specification is processed after the reduction of image resolution in order to enhance the accuracy of the results by histogram specification methods. The experimental results show that the proposed method enhances the accuracy of specification compared to conventional methods.

Fusion of DEMs Generated from Optical and SAR Sensor

  • Jin, Kveong-Hyeok;Yeu, Yeon;Hong, Jae-Min;Yoon, Chang-Rak;Yeu, Bock-Mo
    • 대한공간정보학회지
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    • 제10권5호
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    • pp.53-65
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    • 2002
  • The most widespread techniques for DEM generation are stereoscopy for optical sensor images and SAR interferometry(InSAR) for SAR images. These techniques suffer from certain sensor and processing limitations, which can be overcome by the synergetic use of both sensors and DEMs respectively. This study is associated with improvements of accuracy with consistency of image's characteristics between two different DEMs coming from stereoscopy for the optical images and interferometry for SAR images. The MWD(Multiresolution Wavelet Decomposition) and HPF(High-Pass Filtering), which take advantage of the complementary properties of SAR and stereo optical DEMs, will be applied for the fusion process. DEM fusion is tested with two sets of SPOT and ERS-l/-2 satellite imagery and for the analysis of results, DEM generated from digital topographic map(1 to 5000) is used. As a result of an integration of DEMs, it can more clearly portray topographic slopes and tilts when applying the strengths of DEM of SAR image to DEM of an optical satellite image and in the case of HPF, the resulting DEM.

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NEW LOOK AT THE CONSTRUCTIONS OF MULTIWAVELET FRAMES

  • Kim, Hong-Oh;Kim, Rae-Young;Lim, Jae-Kun
    • 대한수학회보
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    • 제47권3호
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    • pp.563-573
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    • 2010
  • Using the fiberization technique of a shift-invariant space and the matrix characterization of the decomposition of a shift-invariant space of finite length into an orthogonal sum of singly generated shift-invariant spaces, we show that the main result in [13] can be interpreted as a statement about the length of a shift-invariant space, and give a more natural construction of multiwavelet frames from a frame multiresolution analysis of $L^2(\mathbb{R}^d)$.

곡선 그리드상에 정의된 벡터 필드를 위한 다해상도 모형 (Multiresolution Model for Vector Fields Defined over Curvilinear Grids)

  • 정일홍;장우현;조세홍;이봉환
    • 한국멀티미디어학회논문지
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    • 제3권5호
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    • pp.542-549
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    • 2000
  • 본 논문에서는 곡선 그리드상의 2차원 플로우를 분석하고 시각화하기 위한 다해상도 모형을 제안한다. 다해상도 분석은 여러 상세 단계에서 윤곽을 나타내고 분석하는 매우 유용한 도구이다. 일반적으로 벡터 필드의 데이터는 매우 크고 복잡하기 때문에 벡터 필드 시각화에 다해상도 분석을 적용하는 것은 매우 유용하다. 낮은 해상도에서의 근사 값을 사용하면 벡터필드 위상의 전체적인 개요를 짧은 시간 안에 파악할 수 있다. 부분 합성은 사용자가 관심 있는 부분만 합성함으로써 효과적으로 화대 또는 축소할 수 있게 해준다. 이 새로운 모형은 네스트된 곡선 그리드 영역 상에 구분 적으로 정의된 함수의 네스트된 공간에 기초를 두고 있다. 네스트된 영역은 안쪽 경계선의 원래 기하학적 형상을 유지하기 위해 사용된다. 본 논문에서는 이러한 영역 위에서 Haar 웨이브릿에 대한 정제 방정식과 합성 방정식을 제안하고 예제들을 보여준다.

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적응 양자화를 이용한 디지털 워터마킹 (Digital Watermarking Using Adaptive Quantization)

  • 황희근;이동규;이두수
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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    • pp.187-190
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    • 2001
  • In this paper, we present a novel digital watermarking technique based on the concept of multiresolution decomposition and Human Visual System(HVS). Proposed watermarking is to embed watermark by quantization, that is to construct ‘perceptually lossless’quantization matrix, by using a quantization factor for each level and orientation and variance within a band. We compare our approach with another wavelet domain watermarking methods. Simulation results show the superior performance of robustness for variety image distortions.

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형태론적 고속 복원성 여파기 (On the Morphological Fast Reconstructive Filter)

  • 박덕홍;김한균;정호열;오주환;김회진;나상신;선우명훈;정기훈;김용득
    • 전자공학회논문지B
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    • 제31B권12호
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    • pp.81-90
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    • 1994
  • This paper proposes a motphological fast reconstructive filter (FRF) using up/down sampling techniques for reconstructive opening and closing, and a parallel structure for fast multiresolution decomposition. Compuer simulation shows that, compared with the conventional RF, the proposed FRF can reduce the processing time up to 8 times while it maintains a similar performance in reconstructed shapes. Further reduction in the decomposition time achieved by the paralellized algorithm combined with the FRF, which can be applied in areas such as defect detection, image segmentation, pattern recognition, etc.

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Wavelet 변환을 이용한 최적 영상 데이터 다해상도 표현 및 압축에 관한 연구 (A study on optimal Image Data Multiresolution Representation and Compression Through Wavelet Transform)

  • 강경모;정기삼;이명호
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1994년도 추계학술대회
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    • pp.31-38
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    • 1994
  • This paper proposed signal decomposition and multiresolution representation through wavelet transform using wavelet orthonormal basis. And it suggested most appropriate filter for scaling function in multiresoltion representation and compared two compression method, arithmetic coding and Huffman coding. Results are as follows 1. Daub18 coefficient is most appropriate in computing time, energy compaction, image quality. 2. In case of image browsing that should be small in size and good for recognition, it is reasonable to decompose to 3 scale using pyramidal algorithm. 3. For the case of progressive transmittion where requires most grateful image reconstruction from least number of sampls or reconstruction at any target rate, I embedded the data in order of significance after scaling to 5 step. 4. Medical images such as information loss is fatal have to be compressed by lossless method. As a result from compressing 5 scaled data through arithmetic coding and Huffman coding, I obtained that arithmetic coding is better than huffman coding in processing time and compression ratio. And in case of arithmetic coding I could compress to 38% to original image data.

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웨이브렛 변환영역에서의 2단계 가변 블록 다해상도 움직임 추정 (Two-stage variable block-size multiresolution motion estiation in the wavelet transform domain)

  • 김성만;이규원;정학진;박규태
    • 한국통신학회논문지
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    • 제22권7호
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    • pp.1487-1504
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    • 1997
  • In this paper, the two-stage variable block-size multiresolution motion algorithm is proposed for an interframe coding scheme in the wavelet decomposition. An optimal bit allocagion between motion vectors and the prediction error in sense of minimizing the total bit rate is obtained by the proposed algorithm. The proposed algorithm consists of two stages for motion estimatation and only the first stage can be separated and run on its own. The first stage of the algorithm introduces a new method to give the lower bit rate of the displaced frame difference as well as a smooth motion field. In the second stage of the algorithm, the technique is introduced to have more accurate motion vectors in detailed areas, and to decrease the number of motion vectors in uniform areas. The algorithm aims at minimizin gthe total bit rate which is sum of the motion vectors and the displaced frame difference. The optimal bit allocation between motion vectors and displaced frame difference is accomplished by reducing the number of motion vectors in uniform areas and it is based on a botom-up construction of a quadtree. An entropy criterion aims at the control of merge operation. Simulation resuls show that the algorithm lends itself to the wavelet based image sequence coding and outperforms the conventional scheme by up to the maximum 0.28 bpp.

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다중해상도 분해에 의한 부분방전 신호의 특징에 관한 연구 (A Study on the Characteristics of Partial Discharge Signal by Multiresolution Decomposition)

  • 이현동;김충년;이광식;이동인;최상태;이동헌
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1924-1926
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    • 2000
  • This paper deals with the multiresolution analysis of wavelet transform for partial discharge(PD).PD is an electrical discharge that only partically bridges the insulation performance of electrical equipment in high voltage. PD signal is very sensitive and difficult to suppress strong noises such as narrow-band radio frequency noise and random noise. In recently, wavelet transform has become a powerful tool to analysis and process signals in various science and technology fields. In this paper, daubechies family is adopted for the research of the characteristics of PD signals. The results show that the kurtosis is increased with discharge process and skewness is decreased with discharge process, but when PD occured positive range then skewness is increased. Segment 7, 8, 9, 10, 11 values is increased with discharge process, so phase distribution is characterized by 210$\sim$330 ranges.

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웨이브릿 변환 영역의 칼라 및 질감 특징을 이용한 영상검색 (Image Retrieval Using Multiresoluton Color and Texture Features in Wavelet Transform Domain)

  • 천영덕;성중기;김남철
    • 대한전자공학회논문지SP
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    • 제43권1호
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    • pp.55-66
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    • 2006
  • 본 논문에서는 웨이브릿 변환된 영역에서 추출된 다해상도 칼라 및 질감 특징의 효율적인 결합을 이용한 점진적 영상검색 기법을 제안한다. 칼라 특징으로 칼라 영상의 H(Hue)와 S(Saturation) 성분의 칼라 오토코렐로그램을 선택하였고, 질감 특징으로는 V(value) 성분의 BDIP와 BVLC 모멘트를 선택하였다 선택된 특징들에 대하여 웨이브릿 변환 영역의 각 분해 레벨로부터 다해상도 특징벡터들을 얻었다. 칼라와 질감 특징의 다해상도 특징벡터들은 특징들의 차원들과 표준 편차 벡터들에 의해 정규화되어 효율적으로 결합되었고, 저장 공간을 고려하여 각 대상 영상들의 특징벡터들은 효율적으로 양자화 되었으며 점진적 검색 기법을 적용하여 유사도 계산시 계산량을 줄였다. 제안한 방법은 칼라 히스토그램, 칼라 오토코렐로그램, SCD, CSD, 웨이브릿 모멘트, EHD, BDIPBVLC, 칼라 히스토그램과 웨이브릿 모멘트의 결합을 이용한 방법들보다 정확도 대 재현율 평가에서는 평균 $15\%,$ ANMRR 평가에서는 평균 0.2 향상된 성능을 나타내었다. 특히, 제안한 방법은 다양한 해상도를 가지는 영상 DB에서 더욱 우수한 성능을 나타내었다