• 제목/요약/키워드: Histogram

검색결과 2,203건 처리시간 0.031초

히스토그램 분할과 가중치에 기반한 영상 콘트라스트 향상 방법 (Image Contrast Enhancement based on Histogram Decomposition and Weighting)

  • 김매리;정민교
    • 인터넷정보학회논문지
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    • 제10권3호
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    • pp.173-185
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    • 2009
  • 본 논문에서는 두 가지 영상 콘트라스트 향상 기법인 RSWHE (Recursively Separated and Weighted Histogram Equalization)와 RSWHS (Recursively Separated and Weighted Histogram Specification)를 새롭게 제안한다. RSWHE는 히스토그램 평활화 방법에 히스토그램 분할과 가중치 개념을 적용하였고, RSWHS는 히스토그램 명세화 방법에 히스토그램 분할과 가중치 개념을 적용하였다. 제안 방법은 1) 입력 영상의 평균 명도 값을 기준으로 히스토그램을 분할하고, 2) 분할된 각 서브히스토그램(sub-histogram)이 차지하는 확률밀도 값을 계산하며, 3) 계산된 확률밀도 값을 가중치로 사용하여 각 서브히스토그램을 변형한 후, 4) 변형된 각 서브히스토그램을 독립적으로 평활화 하거나 (RSWHE 방법인 경우) 또는 명세화 하게 (RSWHS 방법인 경우) 된다. 다양한 영상에 대한 실험을 통하여, 제안하는 두 방법이 기존의 다른 방법들에 비하여 콘트라스트 향상과 평균 명도 보존 측면에서 우수한 성능을 나타냄을 알 수 있었다.

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DWTHE: 분할 기반의 히스토그램 평활화 (DWTHE: Decomposable Weighted and Thresholded Histogram Equalization)

  • 김매리;정민교
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제15권11호
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    • pp.856-860
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    • 2009
  • 본 논문은 Wang-Ward의 WTHE(Weighted and Thresholded Histogram Equalization) 방법에 히스토그램 분할 개념을 적용한 새로운 영상 화질 개선 방법(DWTHE: Decomposable WTHE)을 제안한다. DWTHE는 먼저 영상의 평균 자기 값 또는 명도 균등 분할점을 기준으로 입력 히스토그램의 영역을 분할하고, 분할된 각 영역의 확률밀도 값을 가중치로 사용하여 새로운 히스토그램을 만든 후, 히스토그램 평활화 과정을 수행하게 된다. 하나의 가중치를 사용하는 WTHE 방법과 다르게, 제안 방법은 히스토그램 분할로 인한 복수외 가중치 값을 사용하게 되며, 실험 결과 제안 방법은 기존 방법에 비해 우수한 화질 개선 효과를 보여주었다.

영역의 컬러특징과 적응적 컬러 히스토그램 빈 매칭 방법을 이용한 내용기반 영상검색 (Content-Based Image Retrieval using Color Feature of Region and Adaptive Color Histogram Bin Matching Method)

  • 박정만;유기형;장세영;한득수;곽훈성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.364-366
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    • 2005
  • From the 90's, the image information retrieval methods have been on progress. As good examples of the methods, Conventional histogram method and merged-color histogram method were introduced. They could get good result in image retrieval. However, Conventional histogram method has disadvantages if the histogram is shifted as a result of intensity change. Merged-color histogram, also, causes more process so, it needs more time to retrieve images. In this paper, we propose an improved new method using Adaptive Color Histogram Bin Matching(AHB) in image retrieval. The proposed method has been tested and verified through a number of simulations using hundreds of images in a database. The simulation results have Quickly yielded the highly accurate candidate images in comparison to other retrieval methods. We show that AHB's can give superior results to color histograms for image retrieval.

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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.

영상 검색을 위한 Shifted 히스토그램 정합 알고리즘 (Shifted Histogram Matching Algorithm for Image Retrieval)

  • 유기형;유승선;육상조;박길철
    • 융합보안논문지
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    • 제7권1호
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    • pp.107-113
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    • 2007
  • 본 논문은 영상의 주요한 색채들을 기반으로 하는 histogram-based 영상 검색을 위한 변형된 히스토그램 방법(SHM)을 제안한다. 히스토그램을 기초로 하는 방법은 이행이나 로테이션과 같은 이미지의 기하학적 변화에 영향을 받지 않기 때문에 컬러 영상 검색에 있어 매우 적합하다. 동일하고 비주얼한 정보를 지녔지만 컬러 강도가 변화된 영상의 경우, 전통적인 히스토그램 인터섹션(HIM)을 이용할 경우에는 현저히 성능이 떨어질 수도 있다. 이 문제를 해결하기 위해 변형된 히스토그램 방법(SHM)을 사용하였다. 실험 결과 변형된 히스토그램 방법(SHM)은 기존의 히스토그램 방식에 비해 더 높은 영상 검색 성능을 보였다.

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Hadoop Based Wavelet Histogram for Big Data in Cloud

  • Kim, Jeong-Joon
    • Journal of Information Processing Systems
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    • 제13권4호
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    • pp.668-676
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    • 2017
  • Recently, the importance of big data has been emphasized with the development of smartphone, web/SNS. As a result, MapReduce, which can efficiently process big data, is receiving worldwide attention because of its excellent scalability and stability. Since big data has a large amount, fast creation speed, and various properties, it is more efficient to process big data summary information than big data itself. Wavelet histogram, which is a typical data summary information generation technique, can generate optimal data summary information that does not cause loss of information of original data. Therefore, a system applying a wavelet histogram generation technique based on MapReduce has been actively studied. However, existing research has a disadvantage in that the generation speed is slow because the wavelet histogram is generated through one or more MapReduce Jobs. And there is a high possibility that the error of the data restored by the wavelet histogram becomes large. However, since the wavelet histogram generation system based on the MapReduce developed in this paper generates the wavelet histogram through one MapReduce Job, the generation speed can be greatly increased. In addition, since the wavelet histogram is generated by adjusting the error boundary specified by the user, the error of the restored data can be adjusted from the wavelet histogram. Finally, we verified the efficiency of the wavelet histogram generation system developed in this paper through performance evaluation.

Piecewise Continuous Linear Density Estimator

  • Jang, Dae-Heung
    • Journal of the Korean Data and Information Science Society
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    • 제16권4호
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    • pp.959-968
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    • 2005
  • The piecewise linear histogram can be used as a simple and efficient tool for the density estimator. But, this piecewise linear histogram is discontinuous function. We suppose the piecewise continuous linear histogram as a simple and efficient tool for the density estimator and the alternative of the piecewise linear histogram.

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손 동작 인식을 위한 Optical Flow Orientation Histogram (Optical Flow Orientation Histogram for Hand Gesture Recognition)

  • ;;오치민;이칠우
    • 한국HCI학회:학술대회논문집
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    • 한국HCI학회 2008년도 학술대회 1부
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    • pp.517-521
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    • 2008
  • Hand motion classification problem is considered as basis for sign or gesture recognition. We promote optical flow as main feature extracted from images sequences to simultaneously segment the motion's area by its magnitude and characterize the motion' s directions by its orientation. We manage the flow orientation histogram as motion descriptor. A motion is encoded by concatenating the flow orientation histogram from several frames. We utilize simple histogram matching to classify the motion sequences. Attempted experiments show the feasibility of our method for hand motion localization and classification.

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히스토그램 스트레칭을 이용한 효율적인 명암 향상 알고리즘 (Efficient Contrast Enhancement Algorithm using Histogram Stretching)

  • 김영로;정지영
    • 디지털산업정보학회논문지
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    • 제6권2호
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    • pp.193-198
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    • 2010
  • In this paper, an efficient contrast enhancement algorithm using histogram stretching is proposed. Histogram equalization (HE) and histogram stretching (HS) are effective techniques for contrast enhancement. However, HE and HS result often in excessive contrast enhancement. Proposed technique not only produces better results than those of conventional contrast enhancement techniques, but is also adaptively adjusted to image contents.

퍼지 멤버쉽 값을 이용한 히스토그램 명세화 (Automatic Histogram Specification Based on Fuzzy Membership Value for Image Enhancement)

  • 황태호;이정훈
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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    • pp.317-320
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    • 2002
  • In this paper, an automatic histogram specification method is proposed for image enhancement, Fuzzy membership value is adopted for the representation of image histogram. The desired PDF is automatically constructed by the fuzzy membership value. Fuzzy membership value is extracted from dark membership, bright membership function and original histogram. The effectual results are demonstrated by desired PDF which meet the image enhancement requirements. The performance and effectiveness are shown by the analysis and the resultant image in comparison with histogram equalization method.