Browsing by Author "Wu, Yi-Chien"

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A System for Front Vehicle Detection and Fast Indexing Using a Single Car-Mounted Camera
(2015-01-01)
Hsu, Chun-Chieh
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Wu, Yi-Chien
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Chen, Hua-Tsung
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Lee, Suh-Yin
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交大名義發表
Video safety becomes a recently arising issue in the automobile industry due to the rapid expansion of car ownership worldwide. Increasing driver assistance systems have been developed for security and accident prevention by continuously monitoring the vehicle surroundings and the driving behaviors to detect potential problems in advance. Since most traffic/criminal accidents are caused by vehicles, recognizing and tracking the fleeing vehicles on the roads are of vital importance. In this paper, we propose a vision-based front vehicle detection and fast indexing system using a single car-mounted camera, which tends to be widespread deployed. First, front vehicle candidates are detected by a cascade of Gentle Adaboost classifiers utilizing Histogram of Oriented Gradients features. To improve the detection accuracy, symmetry of taillights are further employed to filter out the false detected candidates. Once a vehicle is detected, the GPS locations are reported to a central server, so that a database of detections can be maintained and can be provided to the related departments for timely retrieving and quickly indexing the searched vehicles on the maps. Experiments conducted on real videos demonstrate that satisfactory results can be obtained by the proposed detection scheme.
Daytime Preceding Vehicle Brake Light Detection Using Monocular Vision
(2016-01-01)
Chen, Hua-Tsung
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Wu, Yi-Chien
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Hsu, Chun-Chieh
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資訊工程學系
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Department of Computer Science
Advanced vehicle safety is a recently emerging issue appealed from the explosive population of car owners. Increasing driver assistance systems have been developed for warning drivers of potential hazards by analyzing the surroundings with sensors and/or cameras. Issuing vehicle deceleration and potential collision, brake lights are particularly important warning signals, allowing of no neglect. In this paper, we propose a vision-based daytime brake light detection system using a driving video recorder, which tends to be widespread used. At daytime, visual features, motions, and appearances of vehicles are highly visible. However, brake lights, on the contrary, are hard to notice due to low contrast between the brakes lights and environments. Without the significant characteristic of light scattering as at night, the proposed system extracts preceding vehicles with taillight symmetry verification, and then integrates both luminance and radial symmetry features to detect brake lights. A detection refinement process using temporal information is also employed for miss recovery. Experiments are conducted on a test data set collected by front-mounted driving video recorders, and the results verify that the proposed system can effectively detect brake lights at daytime, showing its good feasibility in real-world environments.
Vertex-bipancyclicity of the generalized honeycomb tori
(2008-12-01)
Shih, Yuan-Kang
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Wu, Yi-Chien
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Kao, Shin-Shin
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Tan, Jimmy J. M.
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資訊工程學系
Assume that m, n and s are integers with m >= 2, n >= 4, 0 <= s < n and s is of the same parity of m. The generalized honeycomb tori GHT(m, n, s) have been recognized as an attractive architecture to existing torus interconnection networks in parallel and distributed applications. A bipartite graph G is bipancyclic if it contains a cycle of every even length from 4 to vertical bar V(G)vertical bar inclusive. G is vertex-bipancyclic if for any vertex nu is an element of V(G), there exists a cycle of every even length from 4 to vertical bar V(G)vertical bar that passes nu. A bipartite graph G is called k-vertex-bipancyclic if every vertex lies on a cycle of every even length from k to vertical bar V(G)vertical bar. In this article, we prove that GHT(m, n, s) is 6-bipancyclic, and is bipancyclic for some special cases. Since GHT(m. n. s) is vertex-transitive, the result implies that any vertex of GHT(m. n. s) lies on a cycle of length l, where l >= 6 and is even. Besides, GHT(m, n, s) is vertex-bipancyclic in some special cases. The result is optimal in the sense that the absence of cycles of certain lengths on some GHT(m, n. s)'s is inevitable due to their hexagonal structure. (C) 2008 Elsevier Ltd. All rights reserved.