• Title/Summary/Keyword: Region-Based Method

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Tetrahedral Mesh Generation Using a Mixed Method of a Grid and an Advancing Front Approach (격자법과 전진경계법을 흔합한 사면체 요소망의 자동생성)

  • 김영웅;전성재;채수원
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.1
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    • pp.41-47
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    • 2003
  • In this paper, a tetrahedral mesh generation algorithm which uses a grid based method for interior region and an advancing front method for outer surface region is proposed. In order to apply an advancing front method for outer region of an object, a new operator so called a hole operator has been developed to handle multiple shells. With this grid based approach in the interior region, more stable and uniform meshes can be constructed especially in the interior region.

Region adaptive motion compensated error coding using extension-interpolation/2D-DCT (확장-보간/2D-DCT 기법을 이용한 영역 적응적인 이동보상 오차의 보호화)

  • 조순재;김성대
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.8
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    • pp.1691-1697
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    • 1997
  • This paper presents a new motion compensated error coding method suitable for region based image coding system. Compared with block based conding, the region based coding improves subjective quality as it estimates and compensates 2D (or 3D) translantional, rotational, and scaling motion for each regions. although the region based coding has this advantage, its merit is reduced as bock-DCT (2D-DCT) is used to encode motion-compensated error. To overcome this problem, a new region adaptive motion compensated error coding technique which improver subjective and objective quality in the region boundary is proposed in this paper. In the proposed method, regions with large error are estimated using contour of the regions and contrast between the regions. The regions estiated as those with large error are coded by arbitrarily shaped image segment coding method. The mask information of the coded regions is not transmitted because it is estimated as the same algorithm in the encoder and the decoder. The proposed region adaptive motion conpensated error coding method improves about 0.5dB when it is compared with conventional block based method.

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A Combined Hough Transform based Edge Detection and Region Growing Method for Region Extraction (영역 추출을 위한 Hough 변환 기반 에지 검출과 영역 확장을 통합한 방법)

  • N.T.B., Nguyen;Kim, Yong-Kwon;Chung, Chin-Wan;Lee, Seok-Lyong;Kim, Deok-Hwan
    • Journal of KIISE:Databases
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    • v.36 no.4
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    • pp.263-279
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    • 2009
  • Shape features in a content-based image retrieval (CBIR) system are divided into two classes: contour-based and region-based. Contour-based shape features are simple but they are not as efficient as region-based shape features. Most systems using the region-based shape feature have to extract the region firs t. The prior works on region-based systems still have shortcomings. They are complex to implement, particularly with respect to region extraction, and do not sufficiently use the spatial relationship between regions in the distance model In this paper, a region extraction method that is the combination of an edge-based method and a region growing method is proposed to accurately extract regions inside an object. Edges inside an object are accurately detected based on the Canny edge detector and the Hough transform. And the modified Integrated Region Matching (IRM) scheme which includes the adjacency relationship of regions is also proposed. It is used to compute the distance between images for the similarity search using shape features. The experimental results show the effectiveness of our region extraction method as well as the modified IRM. In comparison with other works, it is shown that the new region extraction method outperforms others.

Segmentation of Arterial Vascular Anatomy around the Stomach based on the Region Growing Based Method

  • Kang, Jiwoo;Kim, Doyoung;Lee, Sanghoon
    • Journal of International Society for Simulation Surgery
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    • v.1 no.2
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    • pp.75-79
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    • 2014
  • Purpose The region growing has a critical problem that it often extract vessels with unexpected objects such as a bone which has a similar intensity characteristics to the vessel. We propose the new method to extract arterial vascular anatomy around the stomach from the CTA volume without the post-processing. Materials and Methods Our method, which is also based on the region growing, requires the two seed points from the use. I automatically extracts perigastric arteries using the adaptive region growing method and it does not need any post-processing. Results The three region growing based methods are used to extract perigastric arteries - the conventional region growings with restrict and loose thresholds each and the proposed method. The 3D visualization from the result of our method shows our method extracted the all required arteries for gastric surgery. Conclusion By extracting perigastric arteries using the proposed method, over-segmentation problem that unexpected anatomical objects such as a rib or backbone are also segmented does not occurs anymore. The proposed method does not need to sensitively determine the thresholds of the similarity function. By visualizing the result, the preoperative simulation of arterial vascular anatomy around the stomach can be possible.

Progressive Image Coding based on SPIHT Using Object Region Transmission Method by Priority (객체 영역 우선 전송 기법을 이용한 SPIHT기반 점진적 영상 부호화)

  • 최은정;안주원;강경원;권기룡;문광석
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.53-56
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    • 2000
  • In progressive image coding, if object region that have main contents in image are transmitted prior to the remained region, this method will be very useful. In this paper, the progressive image coding based on SPIHT using object region transmission method by priority is proposed. First, an original image is transformed by wavelet. Median filtering is used about wavelet transformed coefficient region for extracting object region. This extracted object region encoded by SPIHT. Then encoded object region are transmitted in advance of the remained region. This method is good to a conventional progressive image coding about entire original image. Experimental results show that the proposed method can be very effectively used for image coding applications such as internet retrieval and database searching system.

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Improved Region-Based TCTL Model Checking of Time Petri Nets

  • Esmaili, Mohammad Esmail;Entezari-Maleki, Reza;Movaghar, Ali
    • Journal of Computing Science and Engineering
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    • v.9 no.1
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    • pp.9-19
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    • 2015
  • The most important challenge in the region-based abstraction method as an approach to compute the state space of time Petri Nets (TPNs) for model checking is that the method results in a huge number of regions, causing a state explosion problem. Thus, region-based abstraction methods are not appropriate for use in developing practical tools. To address this limitation, this paper applies a modification to the basic region abstraction method to be used specially for computing the state space of TPN models, so that the number of regions becomes smaller than that of the situations in which the current methods are applied. The proposed approach is based on the special features of TPN that helps us to construct suitable and small region graphs that preserve the time properties of TPN. To achieve this, we use TPN-TCTL as a timed extension of CTL for specifying a subset of properties in TPN models. Then, for model checking TPN-TCTL properties on TPN models, CTL model checking is used on TPN models by translating TPN-TCTL to the equivalent CTL. Finally, we compare our proposed method with the current region-based abstraction methods proposed for TPN models in terms of the size of the resulting region graph.

An Object-based Stereo Matching Method Using Block-based Segmentation (블록 기반 영역 분할을 이용한 객체 기반 스테레오 정합 기법)

  • Kwak No-Yoon
    • Journal of Digital Contents Society
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    • v.5 no.4
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    • pp.257-263
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    • 2004
  • This paper is related to the object-based stereo matching algorithm which makes it possible to estimate inner-region disparities for each segmented region. First, several sample points are selected for effectively representing the segmented region, Next, stereo matching is applied to the small area within segmented region which existed in the neighborhood or each sample point. Finally, inner-region disparities are interpolated using a plane equation with disparity of each selected sample. According to the proposed method, the problem of feature-based method that the depth estimation is possible only in the feature points can be solved through the propagation of the disparity in the sample point into the inside of the region. Also, as selecting sample points in contour of segmented region we can effectively suppress obscurity which is occurred in the depth estimation of the monotone region in area-based methods.

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Detection of a Light Region Based on Intensity and Saturation and Traffic Light Discrimination by Model Verification (명도와 채도 기반의 점등영역 검출 및 모델 검증에 의한 교통신호등 판별)

  • Kim, Min-Ki
    • Journal of Korea Multimedia Society
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    • v.20 no.11
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    • pp.1729-1740
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    • 2017
  • This paper describes a vision-based method that effectively recognize a traffic light. The method consists of two steps of traffic light detection and discrimination. Many related studies have used color information to detect traffic light, but color information is not robust to the varying illumination environment. This paper proposes a new method of traffic light detection based on intensity and saturation. When a traffic light is turned on, the light region usually shows values with high saturation and high intensity. However, when the light region is oversaturated, the region shows values of low saturation and high intensity. So this study proposes a method to be able to detect a traffic light under these conditions. After detecting a traffic light, it estimates the size of the body region including the traffic light and extracts the body region. The body region is compared with five models which represent specific traffic signals, then the region is discriminated as one of the five models or rejected as none of them. Experimental results show the performance of traffic light detection reporting the precision of 97.2%, the recall of 95.8%, and correct recognition rate of 94.3%. These results shows that the proposed method is effective.

Neighboring Elemental Image Exemplar Based Inpainting for Computational Integral Imaging Reconstruction with Partial Occlusion

  • Ko, Bumseok;Lee, Byung-Gook;Lee, Sukho
    • Journal of the Optical Society of Korea
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    • v.19 no.4
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    • pp.390-396
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    • 2015
  • We propose a partial occlusion removal method for computational integral imaging reconstruction (CIIR) based on the usage of the exemplar based inpainting technique. The proposed method is an improved version of the original linear inpainting based CIIR (LI-CIIR), which uses the inpainting technique to fill in the data missing region. The LI-CIIR shows good results for images which contain objects with smooth surfaces. However, if the object has a textured surface, the result of the LI-CIIR deteriorates, since the linear inpainting cannot recover the textured data in the data missing region well. In this work, we utilize the exemplar based inpainting to fill in the textured data in the data missing region. We call the proposed method the neighboring elemental image exemplar based inpainting (NEI-exemplar inpainting) method, since it uses sources from neighboring elemental images to fill in the data missing region. Furthermore, we also propose an automatic occluding region extraction method based on the use of the mutual constraint using depth estimation (MC-DE) and the level set based bimodal segmentation. Experimental results show the validity of the proposed system.

A response surface method based on sub-region of interest for structural reliability analysis

  • Zhao, Weitao;Shi, Xueyan;Tang, Kai
    • Structural Engineering and Mechanics
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    • v.57 no.4
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    • pp.587-602
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    • 2016
  • In structural reliability analysis, the response surface method is widely adopted because of its numerical efficiency. It should be understood that the response function must approximate the actual limit state function accurately in the main region influencing failure probability where it is evaluated. However, the size of main region influencing failure probability was not defined clearly in current response surface methods. In this study, the concept of sub-region of interest is constructed, and an improved response surface method is proposed based on the sub-region of interest. The sub-region of interest can clearly define the size of main region influencing failure probability, so that the accuracy of the evaluation of failure probability is increased. Some examples are introduced to demonstrate the efficiency and the accuracy of the proposed method for both numerical and implicit limit state functions.