• Title/Summary/Keyword: Occluded objects

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Visual Object Tracking by Using Multiple Random Walkers (다중 랜덤 워커를 이용한 객체 추적 기법)

  • Mun, Juhyeok;Kim, Han-Ul;Kim, Chang-Su
    • Journal of Broadcast Engineering
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    • v.21 no.6
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    • pp.913-919
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    • 2016
  • In this paper, we propose the visual tracking algorithm that takes advantage of multiple random walkers. We first show the tracking method based on support vector machine as [1] and suggest a method that suppresses feature vectors extracted from backgrounds while preserve features vectors from foregrounds. We also show how to discriminate between foregrounds and backgrounds. Learned by reducing influences of backgrounds, support vector machine can clearly distinguish foregrounds and backgrounds from the image whose target objects are similar to backgrounds and occluded by another object. Thus, the algorithm can track target objects well. Furthermore, we introduce a simple method improving tracking speed. Finally, experiments validate that proposed algorithm yield better performance than the state-of-the-art trackers on the widely-used benchmark dataset with high speed.

Study on Underwater Object Tracking Based on Real-Time Recurrent Regression Networks Using Multi-beam Sonar Images (실시간 순환 신경망 기반의 멀티빔 소나 이미지를 이용한 수중 물체의 추적에 관한 연구)

  • Lee, Eon-ho;Lee, Yeongjun;Choi, Jinwoo;Lee, Sejin
    • The Journal of Korea Robotics Society
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    • v.15 no.1
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    • pp.8-15
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    • 2020
  • This research is a case study of underwater object tracking based on real-time recurrent regression networks (Re3). Re3 has the concept of generic object tracking. Because of these characteristics, it is very effective to apply this model to unclear underwater sonar images. The model also an pursues object tracking method, thus it solves the problem of calculating load that may be limited when object detection models are used, unlike the tracking models. The model is also highly intuitive, so it has excellent continuity of tracking even if the object being tracked temporarily becomes partially occluded or faded. There are 4 types of the dataset using multi-beam sonar images: including (a) dummy object floated at the testbed; (b) dummy object settled at the bottom of the sea; (c) tire object settled at the bottom of the testbed; (d) multi-objects settled at the bottom of the testbed. For this study, the experiments were conducted to obtain underwater sonar images from the sea and underwater testbed, and the validity of using noisy underwater sonar images was tested to be able to track objects robustly.

High-Frequency Interchange Network for Multispectral Object Detection (다중 스펙트럼 객체 감지를 위한 고주파 교환 네트워크)

  • Park, Seon-Hoo;Yun, Jun-Seok;Yoo, Seok Bong;Han, Seunghwoi
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.8
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    • pp.1121-1129
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    • 2022
  • Object recognition is carried out using RGB images in various object recognition studies. However, RGB images in dark illumination environments or environments where target objects are occluded other objects cause poor object recognition performance. On the other hand, IR images provide strong object recognition performance in these environments because it detects infrared waves rather than visible illumination. In this paper, we propose an RGB-IR fusion model, high-frequency interchange network (HINet), which improves object recognition performance by combining only the strengths of RGB-IR image pairs. HINet connected two object detection models using a mutual high-frequency transfer (MHT) to interchange advantages between RGB-IR images. MHT converts each pair of RGB-IR images into a discrete cosine transform (DCT) spectrum domain to extract high-frequency information. The extracted high-frequency information is transmitted to each other's networks and utilized to improve object recognition performance. Experimental results show the superiority of the proposed network and present performance improvement of the multispectral object recognition task.

Visual Quality Enhancement of Three-Dimensional Integral Imaging Reconstruction for Partially Occluded Objects Using Exemplar-Based Image Restoration

  • Zhang, Miao;Zhong, Zhaolong;Piao, Yongri
    • Journal of information and communication convergence engineering
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    • v.14 no.1
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    • pp.57-63
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    • 2016
  • In generally, the resolution of reconstructed three-dimensional images can be seriously degraded by undesired occlusions in the integral imaging system, because the undesired information of the occlusion overlap the three-dimensional images to be reconstructed. To solve the problem of the undesired occlusion, we present an exemplar-based image restoration method in integral imaging system. In the proposed method, a minimum spanning tree-based stereo matching method is used to remove the region of undesired occlusions in each elemental image. After that, the removed occlusion region of each elemental images are re-established by using the exemplar-based image restoration method. For further improve the performance of the image restoration, the structure tensor is used to solve the filling error cause by discontinuous structures. Finally, the resolution enhanced three-dimensional images are reconstructed by using the restored elemental images. The preliminary experiments are presented to demonstrate the feasibility of the proposed method.

Object Recognition using Neural Network (신경회로망을 이용한 물체인식)

  • Kim, Hyoung-Geun;Park, Sung-Kyu;Song, Chull;Choi, Kap-Seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.3
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    • pp.197-205
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    • 1992
  • In this paper object recognition using neural network is studied. The recognition is accomplished by matching linear line segments which are formed by local features extracted from the curvature points. Since there is similarities among segments. The boundary of models is not distinct in feature space. Due to these indistinctness the ambiguity of recognition occurs, and the recognition rate becomes degraded according to the limitation of boundary decision capability of neural network for similar of features. Object recognition and to improve recognition rate. Local features are used to represent the object effectively. The validity of the object recognition system is demonstrated by experiments for the occluded and varied objects.

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Robust Recognition of 3D Object Using Attributed Relation Graph of Silhouette's (실루엣 기반의 관계그래프 이용한 강인한 3차원 물체 인식)

  • Kim, Dae-Woong;Baek, Kyung-Hwan;Hahn, Hern-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.7
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    • pp.103-110
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    • 2008
  • This paper presents a new approach of recognizing a 3D object using a single camera, based on the extended convex hull of its silhouette. It aims at minimizing the DB size and simplifying the processes for matching and feature extraction. For this purpose, two concepts are introduced: extended convex hull and measurable region. Extended convex hull consists of convex curved edges as well as convex polygons. Measurable region is the cluster of the viewing vectors of a camera represented as the points on the orientation sphere from which a specific set of surfaces can be measured. A measurable region is represented by the extended convex hull of the silhouette which can be obtained by viewing the object from the center of the measurable region. Each silhouette is represented by a relation graph where a node describes an edge using its type, length, reality, and components. Experimental results are included to show that the proposed algorithm works efficiently even when the objects are overlapped and partially occluded. The time complexity for searching the object model in the database is O(N) where N is the number of silhouette models.

The Recognition of Occluded 2-D Objects Using the String Matching and Hash Retrieval Algorithm (스트링 매칭과 해시 검색을 이용한 겹쳐진 이차원 물체의 인식)

  • Kim, Kwan-Dong;Lee, Ji-Yong;Lee, Byeong-Gon;Ahn, Jae-Hyeong
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.7
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    • pp.1923-1932
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    • 1998
  • This paper deals with a 2-D objects recognition algorithm. And in this paper, we present an algorithm which can reduce the computation time in model retrieval by means of hashing technique instead of using the binary~tree method. In this paper, we treat an object boundary as a string of structural units and use an attributed string matching algorithm to compute similarity measure between two strings. We select from the privileged strings a privileged string wIth mmimal eccentricity. This privileged string is treated as the reference string. And thell we wllstructed hash table using the distance between privileged string and the reference string as a key value. Once the database of all model strings is built, the recognition proceeds by segmenting the scene into a polygonal approximation. The distance between privileged string extracted from the scene and the reference string is used for model hypothesis rerieval from the table. As a result of the computer simulation, the proposed method can recognize objects only computing, the distance 2-3tiems, while previous method should compute the distance 8-10 times for model retrieval.

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A Fast Pupil Detection Using Geometric Properties of Circular Objects (원형 객체의 기하학적 특성을 이용한 고속 동공 검출)

  • Kwak, Noyoon
    • Journal of Digital Convergence
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    • v.11 no.2
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    • pp.215-220
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    • 2013
  • They are well-known geometric properties of a circle that the perpendicular bisector of a chord passes through the center of a circle, and the intersection of the perpendicular bisectors of any two chords is its center. This paper is related to a fast pupil detection method capable of detecting the center and the radius of a pupil using these geometric properties at high speed when detecting the pupil region for iris segmentation. The proposed method is characterized as rapidly detecting the center and the radius of the pupil, extracting the candidate points of the circle in human eye images using morphological operations, and finding two chords using four points on the circular edge, and taking the intersection of the perpendicular bisectors of these two chords for its center. The proposed method can not only detect the center and the radius of a pupil rapidly but also find partially occluded pupils in human eye images.

A Study on the salient points detection and object representation for object matching (물체 정합을 위한 특징점 추출 및 물체 표현에 관한 연구)

  • Park, Jeong-Min;Sohn, Kwang-Hoon;Huh, Young
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.6
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    • pp.101-108
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    • 1998
  • An efficient approach to recognize occluded objects is to detect a number of essential features on the boundary of the unknown shape. The salient points including corner points, tangential points and inflection points are detected by the relation of neighboring pixels of each pixel on the boundaries. Corner points are usually detected in the curvature function and tangential points and inflection points are detected by median filtering the curvature function to avoid the effect of quantization noise as corner points is not sufficient to represent an object with lines and arcs. Then, these salient points are used as features for object matching. Discrete Hopfield Neural Network is used for object matching. Experimental results show that the matching result using salient points is better than those of using corner points only when an object consists of lines and arcs.

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Protective Effect of Bupleuri Radix on Hypoxia Reperfusion Induced by PC12 Cell Damage and Global Ischemia in Gerbil (PC12 손상 세포 및 전뇌허혈 유발 Gerbil에 대한 시호 세포보호효과)

  • 최삼열;정승현;신길조;문일수;이원철
    • The Journal of Korean Medicine
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    • v.23 no.4
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    • pp.113-124
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    • 2002
  • Objects: This research was conducted to investigate the protective effect of Bupleuri Radix against ischemic damage using PC12 cells and global ischemia in gerbils, Methods: To observe the protective effect of Bupleuri Radixon ischemic damage, viability and changes in activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and production of malondialdehyde (MDA) were observed after treating PC12 cells with Bupleuri Radix during ischemic damage. Gerbils were divided into three groups: a normal group, a 5-minute two-vessel occlusion (2VO) group and a Bupleun Radix administered group after 2VO. The CCAs were occluded by microclip for 5 minutes, Bupleuri Radix was administered orally for 7 days after 2VO. Histological analysis was performed on the 7th day. For histological analysis, the brain tissue was stained with 1 % of cresyl violet solution. Results: 1. Bupleuri Radix has a protective effect against ischemia in the CA1 area of the gerbil's hippocampus 7 days after 5-minute occlusion. 2. In the hypoxia/reperfusion model using PC12 cells, the Bupleuri Radix has a protective effect against ischemia in the dose of 0.2{\;}\mu\textrm{g}/ml,2{\;}\mu\textrm{g}/ml{\;}and{\;} 20{\;}\mu\textrm{g}/ml$. 3. Bupleuri Radix increased the activities of glutathione peroxidase and catalase. 4. The increased activity of superoxidedismutase (SOD) by ischemic damage might have been induced as an act of self-protection. This study suggests that Bupleuri Radix has some neuroprotective effect against neuronal damage following cerebral ischemia in vivo with a widely used experimental model of cerebral ischemia in Mongolian gerbils. Bupleuri Radix also has protective effect on a hypoxia/reperfusion cell culture model using PC12 cells. Conclusions: Bupleuri Radix has protective effect against ischemic brain damage during the early stages of ischemia.

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