• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.755-758
• /
• 2002

보행자 추적은 무인 자동차 시스템, 보안 또는 감시 시스템, 횡단보도 신호제어 시스템 등 실세계의 다양한 응용 분야에서 사용될 수 있다. 본 논문에서는 걸어다니는 보행자의 움직임 정보를 이용하여 다수의 보행자를 추적하는 새로운 방법을 제안한다. 보행자의 움직임 정보는 연속된 두 개의 비디오 프레임간의 그레이 레벨 차를 이용하여 추하고, 이를 통하여 물체를 검출한다. 검출된 물체에는 보행자뿐만 아니라 다른 이동 물체가 포함될 수 있으므로 프로젝션 히스토그램(PH: Projection Histogram)을 생성한 후 보행자 유형을 기반으로 PH를 분석하여 보행자를 검출, 추적한다. 제안된 방법의 성능 평가를 위해서 복잡한 도시 환경 영상에 적용하고 그 성공적인 결과를 보인다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10b
• /
• pp.931-934
• /
• 2000

움직임 추정 및 보상을 위한 방법 중 가장 많이 사용하는 블록 정합 방법은 어떤 평가 함수와 탐색방법(Search Procedure)을 사용했느냐에 따라 그 성능이 달라지게 된다. 본 논문에서는 평가 함수로써 평균 제곱 오차(Mean Squared Error; MSE), 평균 절대값 오차(Mean Absolute Error; MAE), 화소 차분류(Pel Difference Classification: PDC)을, 탐색 방법으로써 전체 탐색 방법(Full Search Method : FSM), 3단계 탐색 방법(Three Step Search : TSS), 대각 탐색 방법(Cross Search Algorithm ;CSA)을 사용하여 이들의 성능을 각각 비교 분석하여 봄으로써 블록 정합 방법을 이용한 움직임 추정에 대한 전반적인 이해를 도모하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.05a
• /
• pp.1573-1576
• /
• 2004

멀티미디어 압축 및 이동 통신 기술의 발전으로 다양한 형태의 멀티미디어 서비스가 이슈화되고 있다. 비디오를 전송하기 위해서는 많은 대역폭을 필요로 하지만, 모든 네트워크가 높은 수준의 대역 및 처리 능력을 가지는 것은 아니다. 이질적인 네트워크간의 멀티미디어를 서비스하기 위해서는 네트워크 상황 또는 수신자의 처리 능력에 맞도록 재 부호화해야 하지만 그 처리비용이 높다. 트랜스코딩 기법 중에서 시간당 요구된 프레임의 개수를 조절하면 제거된 프레임의 움직임 벡터를 재 사용하여 비트율을 감소시킬 수 있다. 본 논문에서는 기존의 기법보다 향상된 움직임과 중첩 영역의 정보를 적용한 WBVC(Weight-Based Vector Composition) 기법을 제안한다. 실험을 통한 기존의 기법과의 비교 분석 결과, 비슷한 계산 복잡도에서 제안한 WBVC 기법이 높은 성능을 보였다.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.43 no.4
• /
• pp.87-97
• /
• 2015

There's a trend towards vitalization of nightscape planning businesses nationally and locally as well for city image making and activation of regional economy, but there is still no systematic nightscape planning going on for lack of relevant researches and objective evaluations. This study aims to suggest the guideline for nightscape planning by conducting an eye tracking experiment and survey for recognizing the characteristics of a nightscape. Furthermore, the authors intended to verify the eye-tracking method as a tool for landscape evaluation. The research site was restricted in the campus of Virginia Tech, VA, and those were selected by experts' survey among various types of nightscape images. The variables for analyzing the characteristics of nightscape images selected were 'preference', 'safety(fear)' and 'clearness'. 'Fixation duration', 'saccade duration', 'scan path length', and 'pupil size' were selected as the eye movement measurements. The results of this study are as follows: The first outcome found was that there were significant differences among the characteristics(preference, safety and clearness) of a nightscape by MANOVA, and these variables were correlated positively by Pearson's correlation. Secondly, there were differences on fixation duration, saccade duration and scan path depending on the nightscape setting statistically. Also, the eye tracking measurement in an open setting was recorded lower than enclosed settings. In the result of a heat map, we found the meaning of the fixated areas on both viewing without intention and viewing intentionally. It turned out that the fixated areas were consistent with the areas the subjects felt preferred and clarity in all of the nightscape images, which means people usually focus on what they prefer and see clearly in a certain nightscape. Based on this result and previous studies, the authors could make a conclusion that eye tracking method can apply to evaluate nightscape settings in terms of analyzing the whole characteristics and finding specific points for the detailed analysis as well. Therefore, these results can contribute by suggesting nightscape planning, implication of the landscape evaluation, and implication of the eye tracking study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.05a
• /
• pp.571-575
• /
• 2015

This paper propose a temporal histogram -based behavior pattern analysis algorithm to analyze the movement features of moving objects from the image inputted in real-time. For the purpose of tracking and analysis of moving objects, it needs to be performed background learning which separated moving objects from the background. Moving object is extracted as a background learning after identifying the object by using the center of gravity and the coordinate correlation is performed by the object tracking. The start frame of each of the tracked object, the end frame, the coordinates information and size information are stored and managed by the linked list. Temporal histogram defines movement features pattern using x, y coordinates based on time axis, it compares each coordinates of objects for understanding its movement features and behavior pattern. Behavior pattern analysis system based on temporal histogram confirmed high tracking rate over 95% with sustaining high processing speed 45~50fps through the demo experiment.

• Journal of Broadcast Engineering
• /
• v.19 no.5
• /
• pp.699-712
• /
• 2014

In this paper, we propose a new Adaptive Search Range (ASR) decision algorithm for accelerating GPU-based Integer-pel Motion Estimation (IME) of High Efficiency Video Coding (HEVC). For deciding the ASR, we classify a frame into two models using Motion Vector Differences (MVDs) then adaptively decide the search ranges of each model. In order to apply the proposed algorithm to the GPU-based ME process, starting points of the ME are decided using only temporal Motion Vectors (MVs). The CPU decides the ASR as well as the starting points and transfers them to the GPU. Then, the GPU performs the integer-pel ME. The proposed algorithm reduces the total encoding time by 37.9% with BD-rate increase of 1.1% and yields 951.2 times faster ME against the CPU-based anchor. In addition, the proposed algorithm achieves the time reduction of 57.5% in the ME running time with the negligible coding loss of 0.6%, compared with the simple GPU-based ME without ASR decision.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.12
• /
• pp.150-159
• /
• 2014

The latest video coding standard, HEVC can improve the coding efficiency significantly compared with the H.264/AVC. However the HEVC encoder requires much larger computational complexities. The longer 8-tap interpolation filter of the HEVC which is used in a non-integer motion estimation is one of the reasons and this paper aims to reduce the computational complexities. First of all, three shorter-tap interpolation filters for a motion estimation process are tested rather than the use of a standard interpolation filter. In addition, the fast searching strategies to reduce the number of comparisons for choosing the best non-integer motion vector are proposed. Finally, the interpolation process is selectively applied according to the searching strategy. By combining all of the techniques, the experimental results show that the encoding times can be reduced by 13.6%, 18.5% and 21.1% with the coding efficiency penalties of 0.7%, 1.5% and 2.5%, respectively. For the full-HD video sequences, the coding efficiency penalties are reduced to 0.4%, 1.1% and 1.6% at the same level of the encoding time savings, which shows the effectiveness of the proposed schemes for the high resolution video sequences.

• Science & Technology Policy
• /
• v.9 no.2 s.119
• /
• pp.2-5
• /
• 1999

• Korea Multimedia Society
• /
• v.13 no.4
• /
• pp.18-23
• /
• 2009

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1998.10a
• /
• pp.483-486
• /
• 1998