Browsing by Author "Teng, Wen-Chih"

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A novel synchronous multi-intensity IR illuminator hardware implementation for nighttime surveillance
(2015-01-01)
Teng, Wen-Chih
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Chuang, Jen-Hui
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資訊工程學系
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Department of Computer Science
For nighttime surveillance, it's difficult for an ordinary IR illuminator (which has a fixed light intensity) to generate a one-size-fits-all light condition for objects at different distances. Often, we will get overexposed (underexposed) image for an object which is too close to (too far from) the illuminator/camera in the nighttime. To partly resolve such problems, a multi-intensity IR illuminator was proposed which can emit periodically varying intensities of IR light toward an object. However, two major problems remain to be resolved when using such an illuminator, i.e., the "synchronization issue" for background modeling and the "viewing issue" for manual monitoring. In this paper, we propose a novel synchronous multi-intensity infrared (SMIIR) illuminator hardware design to help address these two issues. Hopefully this innovation will open the door to a new era of nighttime surveillance.
A NOVEL VIDEO SUMMARIZATION METHOD FOR MULTI-INTENSITY ILLUMINATED INFRARED VIDEOS
(2013-01-01)
Chuang, Jen-Hui
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Tsai, Wen-Jing
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Chan, Chia-Hsin
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Teng, Wen-Chih
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Lu, I-Chun
In nighttime video surveillance, proper illumination plays a key role for the image quality. For ordinary IR-illuminators with fixed intensity, faraway objects are often hard to identify due to insufficient illumination while nearby objects may suffer from over-exposure, resulting in image foreground/background of poor quality. In this paper we proposed a novel video summarization method which utilizes a novel multi-intensity IR-illuminator to generate images of human activities with different illumination levels. By adopting GMM-based foreground extraction procedure for images acquired for each illumination level, foreground objects with most plausible quality can be selected and merged with a preselected representation for still background. The result brings out a reasonable video summary for moving foreground, which is generally unachievable for nighttime surveillance videos.
Intelligent ICU Video Disp lay for Multi-Intensity IR Illumination
(2014-01-01)
Teng, Wen-Chih
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Chuang, Jen-Hui
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資訊工程學系
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Department of Computer Science
An Intelligent ICU Video Display System for monitoring patients at nighttime is proposed for the next generation ICU environment, wherein infrared light is employed in place of the visible one. However, for simple system with a single light source, patients at different locations may not be illuminated properly due to overexposure/underexposure. To resolve such a problem, a novel IR illuminator is proposed which can emit periodically varying intensity of IR light toward the patients. An effective monitoring system can then be established with multi-channel display of videos of different dynamic range for a single camera. Hopefully our innovation will greatly benefit the ICU healthcare system.
MI3: Multi-Intensity Infrared Illumination Video Database
(2015-01-01)
Chan, Chia-Hsin
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Chen, Hua-Tsung
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Teng, Wen-Chih
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Liu, Chin-Wei
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Chuang, Jen-Hui
Vision-based video surveillance systems have gained increasing popularity. However, their functionality is substantially limited under nighttime conditions due to the poor visibility caused by improper illumination. Equipped on night vision cameras, ordinary infrared (IR) illuminators of fixed-intensity usually lead to the imaging problem of overexposure (or underexposure) when the object is too close to (or too far from) the camera. To overcome this limitation, we use a novel multi-intensity IR illuminator to extend the effective range of distance of camera surveillance, and establish in this paper the MI3 (Multi-Intensity Infrared Illumination) database based on such an illuminator. The database contains intensity varying video sequences of several indoor and outdoor scenes. Ground truths including people counting and foreground labelling are provided for different research usages. Performances of related algorithms are tested for demonstration and evaluation.
Robust License Plate Detection in Nighttime Scenes using Multiple Intensity IR-Illuminator
(2012)
Chen, Yi-Ting
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Chuang, Jen-Hui
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Teng, Wen-Chih
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Lin, Horng-Horng
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Chen, Hua-Tsung
The functionality of video surveillance is significantly degraded by the low illumination and poor visibility under the nighttime environment. However, the demand for nighttime surveillance is no less than the daytime one because of the high incidence of accidents during night. The Infrared (IR) light source with fixed intensity works for only certain distance, resulting in the defect of underexposure/overexposure due to the object being too far from/close to the light source. In this paper an innovative idea is brought up that we use a multiple intensity IR-illuminator to enhance the effective distance of license plate detection. Based on the stroke width of the license ID, license plates are detected in the images under different illuminations and then the results are integrated into a synthesized high dynamic range image, in which the license plate regions and the background scene can be better visualized. Experimental results show that the proposed approach can effectively enlarge the monitored area in both depth and width, as well as enhance the security level of nighttime video surveillance.