• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3769-3789
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• 2018

Social pedestrian groups are the basic elements that constitute a crowd; therefore, detection of such groups is scientifically important for modeling social behavior, as well as practically useful for crowd video understanding. A social group refers to a cluster of members who tend to keep similar motion state for a sustained period of time. One of the main challenges of social group detection arises from the complex dynamic variations of crowd patterns. Therefore, most works model dynamic groups to analysis the crowd behavior, ignoring the existence of stationary groups in crowd scene. However, in this paper, we propose a novel unified framework for detecting social pedestrian groups in crowd videos, including dynamic and stationary pedestrian groups, based on spatiotemporal-oriented energy measurements. Dynamic pedestrian groups are hierarchically clustered based on energy flow similarities and trajectory motion correlations between the atomic groups extracted from principal spatiotemporal-oriented energies. Furthermore, the probability distribution of static spatiotemporal-oriented energies is modeled to detect stationary pedestrian groups. Extensive experiments on challenging datasets demonstrate that our method can achieve superior results for social pedestrian group detection and crowd video classification.

• 한국컴퓨터정보학회논문지
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• 제7권2호
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• pp.124-129
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• 2002

최근 들어 VOD(Video On Demand), 인터넷 방송, 영상 회의 시스템, 및 가상현실(virtual reality) 등의 응용분야에서 동영상이 다양한 형태로 활용되고 있다. 본 연구에서는 웹 캐스팅 등을 통해 영상을 전송 시 왜곡이 심하게 발생하는 장면 전환 위치에서도 디지털 영상에 대한 저작권 정보의 견고성을 유지시킬 수 있는 정보 은닉 방법으로 다중 워터마킹 기법에 대한 연구를 수행한다. 이를 위해 주파수 확산 워터마킹의 장점인 에러에 대한 강인성과 움직임 벡터 워터마킹의 장점인 실시간 성을 결합시킨 개선된 다중 워터마킹을 이용한 새로운 방식의 동영상 편집기를 구현한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.390-392
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• 2003

Video mosaicing techniques have been widely used in virtual reality environments. Especially in GIS field, video mosaics are becoming more and more common in representing urban environments. Such applications mainly use spherical or panoramic mosaics that are based on images taken from a rotating camera around its nodal point. The viewpoint, however, is limited to location within a small area. On the other hand, 2D-mosaics, which are based on images taken from a translating camera, can acquire data in wide area. The 2D-mosaics still have some problems : it can‘t be applied to images taken from a rotational camera in large angle. To compensate those problems , we proposed a novel method for creating video mosaics in 3D space. The proposed algorithm consists of 4 steps: feature -based optical flow detection, camera orientation, 2D-image projection, and image registration in 3D space. All of the processes are fully automatic and successfully implemented and tested with real images.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1434-1449
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• 2019

Video object segmentation is a significant task in computer vision, but its performance is not very satisfactory. A method of video object segmentation using weakly temporal information is presented in this paper. Motivated by the phenomenon in reality that the motion of the object is a continuous and smooth process and the appearance of the object does not change much between adjacent frames in the video sequences, we use a feed-forward architecture with motion estimation to predict the mask of the current frame. We extend an additional mask channel for the previous frame segmentation result. The mask of the previous frame is treated as the input of the expanded channel after processing, and then we extract the temporal feature of the object and fuse it with other feature maps to generate the final mask. In addition, we introduce multi-mask guidance to improve the stability of the model. Moreover, we enhance segmentation performance by further training with the masks already obtained. Experiments show that our method achieves competitive results on DAVIS-2016 on single object segmentation compared to some state-of-the-art algorithms.

• ETRI Journal
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• 제30권2호
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• pp.338-340
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• 2008

In this letter, we propose a novel approach to detecting and tracking apartment buildings for the development of a video-based navigation system that provides augmented reality representation of guidance information on live video sequences. For this, we propose a building detector and tracker. The detector is based on the AdaBoost classifier followed by hierarchical clustering. The classifier uses modified Haar-like features as the primitives. The tracker is a motion-adjusted tracker based on pyramid implementation of the Lukas-Kanade tracker, which periodically confirms and consistently adjusts the tracking region. Experiments show that the proposed approach yields robust and reliable results and is far superior to conventional approaches.

• 대한안전경영과학회지
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• 제3권3호
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• pp.143-149
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• 2001

With the development of computer technologies and the increase of internet users, Internet plays an important role in job-recruitment business. However, almost of the sites which provide job offering and job hunting service, merely have the function such as simple inquiry for information corresponding to job offering and job hunting. In this research, the online website whose task is supporting whole procedure of recruitment for real enterprises is constructed to apply the interview procedures of the real enterprises through internet. We utilize the video conference to increase the reality for interview. Also it has functions such as presentation of application form and resume and self introduction using the video conference. Through the online recruitment website we can expect time and cost saving for recruitment for both sides of enterprise to hunt the person and people to seek the job.

• 한국항공우주학회지
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• 제39권7호
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• pp.660-665
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• 2011

공대공 공대지 가상 공중 교전모의시험이 가능한 가상현실기술이 구현된 가변형 비행 시뮬레이터를 개발하였다. 가변형 비행시뮬레이터의 가변 조종실은 국내에서 운용 중인 F-15K, KF-16, T/A-50 급 기종 모의가 가능하며, 터치형 액정시현기를 활용하여 그래픽 계기를 구현함으로써 누구나 손쉽고 빠르게 기종변경이 가능하다. 조종간과 쓰로틀은 모의기종에 맞게 교체가 가능하며, 외부영상시현장치는 국내최초로 Video See-Through Type HMD를 적용하여 조종사의 몰입감을 최대화 시킬 수 있도록 구성하였다.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1329-1336
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• 2016

This paper develops a 360 degree video system using multiple off-the-shelf webcams and a set of embedded boards. Existing 360 degree cameras have shortcomings that they do not support real-time video generation since recorded videos should be copied to computers or smartphones which then provide stitching. Another shortcoming is that wide FoV(Field of View) cameras are not able to provide sufficiently high resolution. Moreover, resulting images are visually distorted bending straight lines. By employing an array of 65 degree FoV webcams, we were able to generate videos on the spot and achieve over 6K resolution with much less distortion. We describe the configuration and algorithms of the proposed system. The performance evaluation results of our early stage prototype system are presented.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2013년도 하계학술대회
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• pp.229-232
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• 2013

영상실감증대를 위한 시각, 청각정보의 제시방식에 대해서는 많은 진보가 이루어 졌다. 반면 후각은 정의하기 어렵고 다루기 까다롭기 때문에 관련연구를 찾아보기 어렵다. 본 연구에서는 후각정보를 통한 영상실감증대 연구의 첫걸음으로 후각정보에 대한 사용자 수용도를 조사한 후 이에 근거하여 다양한 영상을 분류하였다. 이를 위해 먼저 영상에 냄새가 존재하는지 (냄새존재여부), 영상과 함께 해당 냄새를 경험하고 싶은지 (냄새제시선호), 영상에 어울리는 냄새가 내가 좋아하는 냄새인지 (냄새자체선호), 그리고 영상에 어울리는 냄새가 얼마나 구체적인지 (냄새의 구체성)라는 네 가지 질문을 선정하였다. 각 질문들에 높은 혹은 낮은 점수를 받을 만한 다양한 장르의 영상 (51)개를 수집한 후, 참가자들에게 하나씩 영상을 시청하게 한 후 위의 네 가지 질문에 대해 7점 척도로 평정하게 하였다. 영상분류를 위해 두 질문씩 쌍으로 묶어 각 질문의 척도를 2차원 평면의 X, Y축으로 설정한 후 평정값을 이용하여 영상분류를 위한 산포도를 구성하였다. 2차원 평면의 서로 다른 사분면에 위치한 영상군집들은 영상실감증대를 위한 후각정보 제시에 중요한 시사점을 줄 것으로 기대한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1611-1614
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• 2005

In this paper, a new multi-view 3D video communication system for real-time Reality teleconferencing application is proposed by usin gthe IEEE 1394 digital cameras, Intel Xeon server computer system and Microsoft's DirectShow programming library and its performance is analyzed in terms of image-grabbing frame rate and number of views. The captured two-view image data is compressed by extraction of disparity data between them and transmitted to another client system through the communication network, in which multi-view could be synthesized with this received 2-view data using the intermediate view reconstruction technique and displayed on the multi-view 3D display system. From some experimental results, it is found that the proposed system can display 16-view 3D images with a gray of 8bits and a frame rate of 15fps.