• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.3
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• pp.78-87
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• 2002

A macroblock(MB) in MPEG coded domain can have zero, one, or two motion vectors depending on its frame type and prediction direction (forward-, backward-, or hi-directionally). In this paper, we propose a method that converts these motion vectors on MPEG coded domain as a uniform set, independent of the frame type and the direction of prediction, and directly utilizes these re-analyzed motion vectors for understanding video contents. Also, using this frame-type-independent motion vector, we propose novel methods for detecting and tracking moving objects with frame-based detection accuracy on the compressed domain. These algorithms are performed directly from the MPEG bitstreams after VLC decoding with little time consumption. Experimental results show validity and outstanding performance of our methods.

• The Journal of the Acoustical Society of Korea
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• v.33 no.5
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• pp.326-334
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• 2014

This paper proposes a novel covariance matrix estimation scheme for minimum variance distortionless response (MVDR) beamforming. By accurately tracking direction-of-sound source arrival (DoA) information using audio-visual sensors, the covariance matrix is efficiently estimated by adopting a variable forgetting factor. The variable forgetting factor is determined by considering signal-to-interference ratio (SIR). Experimental results verify that the performance of the proposed method is superior to that of the conventional one in terms of interference/noise reduction and speech distortion.

• Journal of Sensor Science and Technology
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• v.11 no.1
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• pp.28-38
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• 2002

People are important targets for video surveillance and monitoring(VSAM) but difficult to be analyzed. In this paper, a technique to count people in image sequences is dealt as a prerequisite procedure for automatic tracking and behaviour analysis. A group of people is divided at local minima of the line connecting the highest pixels on the binary image of the people extracted from the image taken by a stationary video camera. As the properties of the divided regions vary according to the relative positions of the people in a group, different states are assigned for the completely occluded, partially occluded, completed separated individual, and wrongly divided regions. By analyzing the transition of the states of divided regions, the number of people on the site monitored is estimated. The technique is checked in real experimental situations.

• Journal of the Korea Society of Computer and Information
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• v.6 no.3
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• pp.50-55
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• 2001

We review error resilience techniques for real-time video transport over unreliable networks. For error control on the source coding level, each decoder has to make provisions for error detection, resynchronization. and error concealment. and we review techniques suitable for that purpose. Further, techniques are discussed for intelligent processing of acknowledgment information by the coding control to adapt the source coder to the channel. We review and compare error tracking, error confinement. and reference picture selection techniques for channel-adaptive source coding. We review how feedback-based source codings are related with the precompressed video stored on a media server

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.43-50
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• 2009

Text information in a digital video provides crucial information to acquire semantic information of the video. In the proposed method. text candidate regions are extracted from input sequence by using characteristics of stroke and text candidate regions are localized by using projection to produce text bounding boxes. Bounding boxes containing text regions are verified geometrically and each bounding box existing same location is tracked by calculating matching measure. which is defined as the mean of absolute difference between bounding boxes in the current frame and previous frames. Finally. text regions are enhanced using temporal redundancy of bounding boxes to produce final results. Experimental results for various videos show the validity of the proposed method.

• Annual Conference of KIPS
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• 2011.04a
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• pp.1024-1027
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• 2011

본 논문은 HD (High-definition) video, SD (Standard-definition) video, low quality video, handset video, 4 가지 Imaging Device 에 대한 프로파일 분석을 통해 비디오 프레임 상에 나타나는 위 변조를 검사하는 방법을 제안한다. High-definition video, Standard-definition video, low quality video, handset video 에 대한 분석을 하고 각 영상의 특이 점을 파악 하여 분류한 클래스에 대한 프로파일검사를 통해 EM Algorithm 을 이용하여 영상의 위 변조를 검사 하고 영상의 신뢰성을 높인다.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.115-123
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• 2015

The incremental learning method performs well in face face tracking. However, it has a drawback in that it is sensitive to the tracking error in the previous frame due to the environmental changes. In this paper, we propose a selective incremental learning method to track a face more reliably under various conditions. The proposed method is robust to illumination variation by using the LBP(Local Binary Pattern) features for each individual frame. We select patches to be used in incremental learning by using Staggered Multi-Scale LBP, which prevents the propagation of tracking errors occurred in the previous frame. The experimental results show that the proposed method improves the face tracking performance on the videos with environmental changes such as illumination variation.

• Spatial Information Research
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• v.21 no.3
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• pp.11-19
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• 2013

Compared with traditional video monitoring systems that provide a video-recording function as a main service, an intelligent video monitoring system is capable of extracting/tracking objects and detecting events such as car accidents, traffic congestion, pedestrian detection, and so on. Thus, the object tracking is an essential function for various intelligent video monitoring and surveillance systems. In this paper, we propose a background and local histogram-based object tracking approach for intelligent video monitoring systems. For robust object tracking in a live situation, the result of optical flow and local histogram verification are combined with the result of background subtraction. In the proposed approach, local histogram verification allows the system to track target objects more reliably when the local histogram of LK position is not similar to the previous histogram. Experimental results are provided to show the proposed tracking algorithm is robust in object occlusion and scale change situation.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.2
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• pp.19-25
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• 2013

In this paper, we propose an approach to tracking road regions from video sequences. The proposed method segments and tracks road regions by utilizing the prior information from the result of the previous frame. For the efficiency of the system, we have a simple assumption that the road region is usually shown in the lower part of input images so that lower 60% of input images is set to the region of interest(ROI). After initial segmentation using flood-fill algorithm, we merge neighboring regions based on color similarity measure. The previous segmentation result, in which seed points for the successive frame are extracted, is used as prior information to segment the current frame. The similarity between the road region of the previous frame and that of the current frame is measured by the modified Jaccard coefficient. According to the similarity we refine and track the detected road regions. The experimental results reveal that the proposed method is effective to segment and track road regions in noisy and non-noisy environments.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1111-1116
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• 1997

In a period from Sep 1994 to Sep 1996, 38 patients were treated for spontaneous pneumothorax by video-assisted thoracic surgery(VATS). 31 male and 7 female patients with ages between 17 and 79(mean 30.0 years). No death occured. The postoperative complication rate of VATS was 7.9%(3/38). We noted no recurrence of pneumothorax, 3 wound dehiscence, 3 persistent air leak(>7days) in the patients. We compared theses results with thoracoscopic surgery of spontaneous pneumothorax in 38 cases(Group A), with cases of 21 patients(Group B) performed by the thoracotomy in the same period. There have been no recurrence in groud A, and one recurrence in group B at a median follow-up of 14.37$\pm$7.48 months and 16.81 $\pm$7.12 months, respectively. There was no significant difference in the duration of operation time including induction time between VATS and thoracotomy, but postoperative hospital stay and chest tube drainage periods were all less for these undergone VATS. Postoperative complication was less in group A(3/38=7.9%, 3 cases with persistent air leak >7days, all developed wound dehiscence, too), than in group B(9/21=42.9%, 8 cases with persistent air leak more than 7days, including 2 wound dehiscence, one recurrence, and the other one case of empyema). In our experience, VATS has the effectiveness of thoracic surgery for treating thoracic problems, has resulted in surgical intervention in spontaneous pneumothorax.