• Title/Summary/Keyword: watershed algorithm

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A Study On Watershed Region Extraction Based On Edge Information (에지 정보를 이용한 watershed 영역 추출에 관한 연구)

  • 이원효;조상현;설경호;주동현;김두영
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.449-452
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    • 2003
  • This paper propose a extracting method of the region for image using segmentation and edge information. First propose algorithm extract information using canny edge detector and the image was divided by watershed segmentation. And it extract the mage with edge information by merging region. Finally we compare the proposed method with levelset method. In the result proposed method not only extract the image with accurate region but also reduce operation time.

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Background Subtraction for Moving Cameras based on trajectory-controlled segmentation and Label Inference

  • Yin, Xiaoqing;Wang, Bin;Li, Weili;Liu, Yu;Zhang, Maojun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.10
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    • pp.4092-4107
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    • 2015
  • We propose a background subtraction method for moving cameras based on trajectory classification, image segmentation and label inference. In the trajectory classification process, PCA-based outlier detection strategy is used to remove the outliers in the foreground trajectories. Combining optical flow trajectory with watershed algorithm, we propose a trajectory-controlled watershed segmentation algorithm which effectively improves the edge-preserving performance and prevents the over-smooth problem. Finally, label inference based on Markov Random field is conducted for labeling the unlabeled pixels. Experimental results on the motionseg database demonstrate the promising performance of the proposed approach compared with other competing methods.

Flood Runoff Analysis on the Anseong-cheon watershed using TOPMODEL and Muskingum method. (TOPMODEL과 Muskingum 기법을 이용한 안성천유역의 홍수유출분석)

  • Kwon, Hyung-Joong;Kim, Seong-Joon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.289-292
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    • 2002
  • In this study, a topography based hydrologic model (TOPMODEL) was tested on the Anseong-cheon watershed. Pit in watershed was removed by liner trend surface interpolator. The DTM Analysis program is used to derived a distribution of ln($a/tan{\beta}$) values from DEM (Digital Elevation Model) using the MDF (Multiple Direction Flow) algorithm of Quinn et al (1995). Current TOPMODEL program limits are number of time step, ln($a/tan{\beta}$) increment, delay histogram ordinate and size of subcatchment pixel maps. Therefore, TOPMODEL is not suitable for application of large watershed. Muskingum method and watershed division enhance grid pixel resolution for rainfall-runoff simulation accuracy.

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The Watershed Image Segmentation Iteration Method (개선된Watershed영상분할방법)

  • 권기홍
    • Journal of the Korea Computer Industry Society
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    • v.4 no.12
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    • pp.923-928
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    • 2003
  • A severe drawback to the calculation of watershed images is over segmentation. Relevant object contours are lost in a sea of irrelevant ones. This is partly caused by random noise, inherent to a data, which gives rise to additional local minima, such that many catchments basins are further subdivided. Proposed watershed image segmentation algorithm is iteratively merging neighboring regions that have similar gray level distributions, to restore image.

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Watershed Segmentation of High-Resolution Remotely Sensed Imagery

  • WANG Ziyu;ZHAO Shuhe;CHEN Xiuwan
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.107-109
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    • 2004
  • High-resolution remotely sensed data such as SPOT-5 imagery are employed to study the effectiveness of the watershed segmentation algorithm. Existing problems in this approach are identified and appropriate solutions are proposed. As a case study, the panchromatic SPOT-5 image of part of Beijing urban areas has been segmented by using the MATLAB software. In segmentation, the structuring element has been firstly created, then the gaps between objects have been exaggerated and the objects of interest are converted. After that, the intensity valleys have been detected and the watershed segmentation have been conducted. Through this process, the objects in an image are divided into separate objects. Finally, the effectiveness of the watershed segmentation approach for high-resolution imagery has been summarized. The approach to solve the problems such as over-segmentation has been proposed.

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Spatio-temporal video segmentation using a joint similarity measure (결합 유사성 척도를 이용한 시공간 영상 분할)

  • 최재각;이시웅;조순제;김성대
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.6
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    • pp.1195-1209
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    • 1997
  • This paper presents a new morphological spatio-temporal segmentation algorithm. The algorithm incorporates luminance and motion information simultaneously, and uses morphological tools such as morphological filtersand watershed algorithm. The procedure toward complete segmentation consists of three steps:joint marker extraction, boundary decision, and motion-based region fusion. First, the joint marker extraction identifies the presence of homogeneours regions in both motion and luminance, where a simple joint marker extraction technique is proposed. Second, the spatio-temporal boundaries are decided by the watershed algorithm. For this purposek, a new joint similarity measure is proposed. Finally, an elimination ofredundant regions is done using motion-based region function. By incorporating spatial and temporal information simultaneously, we can obtain visually meaningful segmentation results. Simulation results demonstratesthe efficiency of the proposed method.

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A hierarchical semantic video object racking algorithm using mathematical morphology

  • Jaeyoung-Yi;Park, Hyun-Sang;Ra, Jong-Beom
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1998.06b
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    • pp.29-33
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    • 1998
  • In this paper, we propose a hierarchical segmentation method for tracking a semantic video object using a watershed algorithm based on morphological filtering. In the proposed method, each hierarchy consists of three steps: First, markers are extracted on the simplified current frame. Second, region growing by a modified watershed algorithm is performed for segmentation. Finally, the segmented regions are classified into 3 categories, i.e., inside, outside, and uncertain regions according to region probability values, which are acquired by the probability map calculated from a estimated motion field. Then, for the remaining uncertain regions, the above three steps are repeated at lower hierarchies with less simplified frames until every region is decided to a certain region. The proposed algorithm provides prospective results in video sequences such as Miss America, Clair, and Akiyo.

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Robust Road Detection using Adaptive Seed based Watershed Segmentation (적응적 Seed를 기초로한 분수계 분할을 이용한 차도영역 검출)

  • Park, Han-dong;Oh, Jeong-su
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.687-690
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    • 2015
  • Forward collision warning systems(FCWS) and lane change assist systems(LCAS) need regions of interest for detecting lanes and objects as road regions. Watershed segmentation is effective algorithm that classify the road. That algorithm is split results appear differently depending on Watershed line with local minimum in the early part of the seed. If not road regions or vehicles combined the road's seed, It segment road with the others. For compensate the that defect, It has to adaptive change by road environment. The method is that image segmentate the several of regions of interest. Then It is set in a straight line that is detected in regions of interest. If It was detected cars on seed, seed is adjusted the location. And If It wasn't include the line, seed is adjusted the length for final decision the seed. We can detect the road region using the final seed that selected according to the road environment.

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Parameter Optimization of Long and Short Term Runoff Models Using Genetic Algorithm (유전자 알고리즘을 이용한 장·단기 유출모형의 매개변수 최적화)

  • Kim, Sun-Joo;Jee, Yong-Geun;Kim, Phil-Shik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.5
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    • pp.41-52
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    • 2004
  • In this study, parameters of long and short term runoff model were optimized using genetic algorithm as a basic research for integrated water management in a watershed. In case of Korea where drought and flood occurr frequently, the integrated water management is necessary to minimize possible damage of drought and flood. Modified TANK model was optimized as a long term runoff model and storage-function model was optimized as a short term runoff model. Besides distinguished parameters were applied to modified TANK model for supplementing defect that the model estimates less runoff in the storm period. As a result of application, simulated long and short term runoff results showed 7% and 5% improvement compared with before optimized on the average. In case of modified TANK model using distinguished parameters, the simulated runoff after optimized showed more interrelationship than before optimized. Therefore, modified TANK model can be applied for the long term water balance as an integrated water management in a watershed. In case of storage-function model, simulated runoff in the storm period showed high interrelationship with observed one. These optimized models can be applied for the runoff analysis of watershed.

Parameter Optimization for Runoff Calibration of SWMM (SWMM의 유출량 보정을 위한 매개변수 최적화)

  • Cho, Jae-Heon;Lee, Jong-Ho
    • Journal of Environmental Impact Assessment
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    • v.15 no.6
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    • pp.435-441
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    • 2006
  • For the calibration of rainfall-runoff model, automatic calibration methods are used instead of manual calibration to obtain the reliable modeling results. When mathematical programming techniques such as linear programming and nonlinear programming are applied, there is a possibility to arrive at the local optimum. To solve this problem, genetic algorithm is introduced in this study. It is very simple and easy to understand but also applicable to any complicated mathematical problem, and it can find out the global optimum solution effectively. The objective of this study is to develope a parameter optimization program that integrate a genetic algorithm and a rainfall-runoff model. The program can calibrate the various parameters related to the runoff process automatically. As a rainfall-runoff model, SWMM is applied. The automatic calibration program developed in this study is applied to the Jangcheon watershed flowing into the Youngrang Lake that is in the eutrophic state. Runoff surveys were carried out for two storm events on the Jangcheon watershed. The peak flow and runoff volume estimated by the calibrated model with the survey data shows good agreement with the observed values.