• Title/Summary/Keyword: 마스크 기법

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Efficiency Assessment of Analysing Coastal Geomorphic Landscape Change by Satellite Image Interpretation (위성영상을 이용한 해안습지 지형경관 변화 분석의 효율성 평가)

  • 박의준;구자용
    • Journal of the Korean Geographical Society
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    • v.38 no.5
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    • pp.822-834
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    • 2003
  • It is difficult to analyse geomorphic landscape changes effectively by a field survey. A satellite image interpretation may play an important role to overcome such a problem. The purpose of this study is to assess the accuracy of different method to identify geomorphic landscape change by using satellite imagery. The study area is the Yongjong coastal wetland in which a huge man-made environmental change occured to build a new international airport in the past decade. These changes may be summarized that a coastal landscape has been changed to a terrestrial landscape, and also a natural landscape to a man-made landscape. In order to detect these changes, we applied three different satellite interpreting methods, including a binary change mask using band difference. a binary change mask using normalized band difference. and a binary change mask using NDVI. We concluded that a binary change mask using NDVI is the best method among three different methods analysing the coastal geomorphic-landscape changes.

Enhanced image detail control using Multi Channel Unsharp Mask Technique (멀티채널 언샤프 마스크 기법을 이용한 영상 세부제어)

  • Cho, Hyun-Ji;Nam, Doohee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.1
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    • pp.165-170
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    • 2015
  • The unsharp mask technique emphasize the boundary of the image by adding the boundary of the original image. This technique improves quality by emphasize its boundaries but produce rough image from image noise. The multi channel unsharp mask is possible to enhance entire contrast of the image by applying at least two channels of unsharp mask. However, There is limitations to strengthen boundaries even if the scale strongly applies the multi channel unsharp mask technique. To solve this problem, linear scaling to nonlinear scaling by applying exponential function to existing multi channel unsharp mask technique. Experimental results show enhanced contrast for desired area because of control scaling in details compared with existing unsharp mask technique.

Spot detection of Optical lens using the image processing (영상 처리에 의한 광학렌즈 이물 검출)

  • Song, Young-Jun;Kim, Dong-Woo;Kim, Nam;Ahn, Jae-Hyeong
    • Proceedings of the KAIS Fall Conference
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    • pp.73-75
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    • 2009
  • 본 논문은 영상 처리에 의해 광학렌즈의 먼지 및 이물질의 유무를 검출하기 위한 방법을 제안한다. 현재 사용되고 있는 비접촉 검사용 비젼 시스템은 마스크 기법을 활용하여 기준 영상에 비해 어느 정도의 잡음이 있는지를 검사한다. 그러나 조명의 정도, 반사 및 이물질의 유형에 따라 검출하기가 어렵다. 이를 해결하기 위해 파란색 LED 광원을 수평축에 설치하여 양각 부분의 에지들을 더욱 강조하는 시스템을 구현하였다. 이물질 검출은 간단한 소벨 에지 마스크를 사용하고 이물질의 크기에 따라 먼지 및 이물질에 대한 판단을 결정하였다. 크기 및 색상이 틀린 렌즈를 사용하여 실험한 결과 일반 영상에서 검출한 것보다 파란색 LED 광원과 영상처리에 의해 잡음 및 이물질을 강건하게 검출하여 렌즈의 자동 검사용 로봇 비젼 시스템에 적용이 가능하다.

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The Measurement of Bubble Driven Flow Using PIV and Digital Mask Technique (PIV 기법과 Digital Mask 기법을 적용한 버블유동 측정)

  • Kim, Sang-Moon;Kim, Hyun-Dong;Kim, Kyung-Chun
    • Proceedings of the KSME Conference
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    • pp.2700-2703
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    • 2008
  • An experiment on bubble-driven flow was performed in order to understand fundamental knowledge of flow structure around a rising bubble in a stagnant fluid. The measurement technique consists of a combination of the three most often used PIV techniques in multiphase flows: PIV with fluorescent tracer particles, the digital phase separation with a masking technique and a shadowgraphy. The key point of the measurement is that the background intensity of a PIV recording can be shifted to a higher level than a bubble region using a shadowgraphy in order to distinguish from fluorescent particles and a bubble as well. Flow fields were measured without an inaccurate analysis around a fluid-bubble interface by using only one camera simply.

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Face Detection for Intelligent Video Conference System (지능형 영상회의를 위한 얼굴검출)

  • Park, Jae-Hyeon;Park, Gyu-Sik;On, Seung-Yeop;Kim, Cheon-Guk
    • The KIPS Transactions:PartB
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    • v.8B no.1
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    • pp.20-27
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    • 2001
  • 얼굴검출은 현재 많은 연구가 활발히 진행되고 있는 분야로 보안, 인식 등 다양한 응용분야를 갖는다. 본 논문은 카메라가 화자의 이동에 따라 이를 추적하여 회전하고 회의상황에 맞는 앵글을 유지하는 지능형 영상회의 시스템 개발의 기본요소인 화자검출의 선행단계로 얼굴검출에 대한 새로운 방법을 제안한다. RGB 색 공간의 입력영상을 YIQ 공간으로 변환한 후 IQ 성분은 피부영역검출에 Y 성분은 얼굴의 특성을 추출하는데 사용된다. 색 분포도를 이용하여 피부영역을 검출하고, 마스크를 누적 적용하여 잡음을 제거한 후 얼굴의 구조적인 특성과 명암의 분포를 이용하여 얼굴영역이 검출된다. 실험결과 다양한 배경의 영상에서 여러 명의 얼굴이 오류 없이 검출됨이 관찰되었다.

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Eigenvoice Adaptation of Classification Model for Binary Mask Estimation (Eigenvoice를 이용한 이진 마스크 분류 모델 적응 방법)

  • Kim, Gibak
    • Journal of Broadcast Engineering
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    • v.20 no.1
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    • pp.164-170
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    • 2015
  • This paper deals with the adaptation of classification model in the binary mask approach to suppress noise in the noisy environment. The binary mask estimation approach is known to improve speech intelligibility of noisy speech. However, the same type of noisy data for the test data should be included in the training data for building the classification model of binary mask estimation. The eigenvoice adaptation is applied to the noise-independent classification model and the adapted model is used as noise-dependent model. The results are reported in Hit rates and False alarm rates. The experimental results confirmed that the accuracy of classification is improved as the number of adaptation sentences increases.

An X-masking Scheme for Logic Built-In Self-Test Using a Phase-Shifting Network (위상천이 네트워크를 사용한 X-마스크 기법)

  • Song, Dong-Sup;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.2
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    • pp.127-138
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    • 2007
  • In this paper, we propose a new X-masking scheme for utilizing logic built-in self-test The new scheme exploits the phase-shifting network which is based on the shift-and-add property of maximum length pseudorandom binary sequences(m-sequences). The phase-shifting network generates mask-patterns to multiple scan chains by appropriately shifting the m-sequence of an LFSR. The number of shifts required to generate each scan chain mask pattern can be dynamically reconfigured during a test session. An iterative simulation procedure to synthesize the phase-shifting network is proposed. Because the number of candidates for phase-shifting that can generate a scan chain mask pattern are very large, the proposed X-masking scheme reduce the hardware overhead efficiently. Experimental results demonstrate that the proposed X-masking technique requires less storage and hardware overhead with the conventional methods.

Eyelid Detection Algorithm Based on Parabolic Hough Transform for Iris Recognition (홍채 인식을 위한 포물 허프 변환 기반 눈꺼풀 영역 검출 알고리즘)

  • Jang, Young-Kyoon;Kang, Byung-Jun;Park, Kang-Ryoung
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.1
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    • pp.94-104
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    • 2007
  • Iris recognition is biometric technology which uses a unique iris pattern of user in order to identify person. In the captured iris image by conventional iris recognition camera, it is often the case with eyelid occlusion, which covers iris information. The eyelids are unnecessary information that causes bad recognition performance, so this paper proposes robust algorithm in order to detect eyelid. This research has following three advantages compared to previous works. First, we remove the detected eyelash and specular reflection by linear interpolation method because they act as noise factors when locating eyelid. Second, we detect the candidate points of eyelid by using mask in limited eyelid searching area, which is determined by searching the cross position of eyelid and the outer boundary of iris. And our proposed algorithm detects eyelid by using parabolic hough transform based on the detected candidate points. Third, there have been many researches to detect eyelid, but they did not consider the rotation of eyelid in an iris image. Whereas, we consider the rotation factor in parabolic hough transform to overcome such problem. We tested our algorithm with CASIA Database. As the experimental results, the detection accuracy were 90.82% and 96.47% in case of detecting upper and lower eyelid, respectively.