• Journal of Internet of Things and Convergence
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• v.8 no.4
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• pp.41-47
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• 2022

Smoothing is a transmission plan that converts video data stored at a variable bit rate into a fixed bit rate. Algorithms for smoothing include CBA, which aims to minimize the number of transmission rate increases, MCBA, which minimizes the number of transmission rate changes, and MVBA algorithms that minimize the amount of transmission rate change. This paper compares the proposed algorithm with the CBA algorithm with various video data, buffer size, and performance evaluation factors as a follow-up to the proposed smoothing algorithm that minimizes (maximizes) the transmission rate increase (decrease) when the server requires more bandwidth The evaluation factors used were compared with the number of changes in the fps rate, the minimum fps, the average fps, fps variability, and the number of frames to be discarded. As a result of the comparison, the proposed algorithm showed superiority in comparing the number of fps rate changes and the number of frames discarded.

• Journal of Internet of Things and Convergence
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• v.9 no.2
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• pp.11-17
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• 2023

Smoothing is to creating a transmission plan consisting of sections of frames that can be sent at the same transmission rate for compressed and stored video data. Various algorithms have been studied for the smoothing to minimize the number of transmission rate changes, the number of transmission rate changes, and the amount of transmission rate increase. This study evaluates the performance of a smoothing algorithm that minimizes the increase in transmission rates and maximizes the increase in transmission rates when the transmission rate is required to maximize the excess bandwidth to be secured by the server in an environment with limited server bandwidth. The available transmission rates and buffer sizes available in the server are set in various ways and evaluated by the number of fps changes, the minimum fps, the average fps, and fps variability. As a result of the comparison, the proposed algorithm showed excellent average fps and fps variability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.3
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• pp.1058-1070
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• 2014

There are two major ways to implement depth estimation, multiple image depth estimation and single image depth estimation, respectively. The former has a high hardware cost because it uses multiple cameras but it has a simple software algorithm. Conversely, the latter has a low hardware cost but the software algorithm is complex. One of the recent trends in this field is to make a system compact, or even portable, and to simplify the optical elements to be attached to the conventional camera. In this paper, we present an implementation of depth estimation with a single image using a graphics processing unit (GPU) in a desktop PC, and achieve real-time application via our evolutional algorithm and parallel processing technique, employing a compute shader. The methods greatly accelerate the compute-intensive implementation of depth estimation with a single view image from 0.003 frames per second (fps) (implemented in MATLAB) to 53 fps, which is almost twice the real-time standard of 30 fps. In the previous literature, to the best of our knowledge, no paper discusses the optimization of depth estimation using a single image, and the frame rate of our final result is better than that of previous studies using multiple images, whose frame rate is about 20fps.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.493-496
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• 2009

Many AR (Augmented Reality) applications have been interested in a marker-less tracking since the tracking methods give camera poses without attaching explicit markers. In this paper, we propose a new marker-less page recognition and tracking algorithm for an AR book application such as DigilogBook. The proposed method only requires orthogonal images of pages, which need not to be trained for a long time, and the algorithm works in real-time. The page recognition is done in two steps by using SIFT (Scale Invariant Feature Transform) descriptors and the comparison evaluation function. And also, the method provides real-time tracking with 25fps ~ 30fps by separating the page recognition and the frame-to-frame matching into two multi-cores. The proposed algorithm will be extended to various AR applications that require multiple objects tracking.

• Journal of Korea Game Society
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• v.15 no.3
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• pp.177-188
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• 2015

In-game cheating by the use of unauthorized software programs has always been a big problem that they can damage in First Person Shooting games, although companies operate a variety of client security solutions in order to prevent games from the cheating attempts. This paper proposes a method for detecting cheaters in FPS games by using game log analysis in a server-side. To accomplish this, we did a comparative analysis of characteristics between cheaters and general users focused on commonly loaded logs in the game. We proposed a cheating detection model by using artificial neural network algorithm. In addition, we did the performance evaluation of the proposed model by using the real dataset used in business.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.469-476
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• 2005

To date, many viable smart base isolation systems have been proposed. In this study, a novel friction pendulum system (FPS) and an MR damper are employed as the isolator and supplemental damping device, respectively. A fuzzy logic controller (FLC) is used to modulate the MR damper. A genetic algorithm (GA) is used for optimization of the FLC. The main purpose of employing a GA is to determine appropriate fuzzy control rules as well to adjust parameters of the membership functions. To this end, a GA with a local improvement mechanism is applied. Neuro-fuzzy models are used to represent dynamic behavior of the MR damper and FPS. Effectiveness of the proposed method for optimal design of the FLC is judged based on computed responses to several historical earthquakes. It has been shown that the proposed method can find appropriate fuzzy rules and the GA-optimized FLC outperforms not only a passive control strategy but also a human-designed FLC and a conventional semi-active control algorithm.

• Journal of Korea Game Society
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• v.12 no.4
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• pp.23-31
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• 2012

The collision processing is one of the essential factors to realize physical principles in the game, and it gives liveliness to the game. The collision processing requires a large amount of operations, and significantly affects the game performance. To address this problem, many studies have been conducted to reduce the operation volume, and the SAP algorithm is being widely used. However, its efficiency is low because it involves repetitive operations. In this study, a distance-based SAP algorithm was proposed to reduce the operation volume for the collision processing and address the problem of the SAP algorithm. A test was conducted to measure the FPS using the simulation program, which was developed with the proposed algorithm. The FPS was 2-33 times higher with the proposed algorithm, which indicated that the efficiency of the collision processing was improved.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.750-755
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• 1998

Due to the temporal spatial correlation of the image sequence, the motion vector of a block is highly related to the motion vectors of its adjacent blocks in the same image frame. If we can obtain useful and enough information from the adjacent motion vectors, the total number of search points used to find the motion vector of the block may be reduced significantly. Using that idea, an efficient fuzzy prediction search (FPS) algorithm for block motion estimation is proposed in this paper. Based on the fuzzy inference process, the FPS can determine the motion vectors of image blocks quickly and correctly.

• Journal of the Korea Computer Graphics Society
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• v.6 no.3
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• pp.35-40
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• 2000

There are two problems in H.26X compression technique. One is compressing time in encoding process and the other is degradation of the decoded video quality due to high compression rate. For transferring moving pictures in real-time, it is required to adopt massively high compression. In this case, there are a lot of losses of an original video data and that results in degradation of quality. Especially degradation called by blocking artifact may be produced. The blocking artifact effect is produced by DCT-based coding techniques because they operate without considering correlation between pixels in block boundaries. So it represents discontinuity between adjacent blocks. This paper describes methods of quality compensation for H.26x decoded data and enhancing encoding speed for real-time operation. Our goal of the quality compensation is not to make the decoded video identical to a original video but to make it perceived better through human eyes. We suggest an algorithm that reduces block artifact and clears decoded video in decoder. To enhance encoding speed, we adopt new four-step search algorithm. As shown in the experimental result, the quality compensation provides better video quality because of reducing blocking artifact. And then new four-step search algorithm with $MMX^{TM}$ implementation improves encoding speed from 2.5 fps to 17 fps.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.49-52
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• 2006

오늘날 컴퓨터의 발달과 인터넷의 확산으로 멀티미디어 컨텐츠의 보급이 급격히 확대되고 있으며, 이들 컨텐츠에는 원거리 화상회의, 감시시스템, 주문형 비디오(VOD), 주문형 뉴스(NOD), 디지털 편집 시스템 등 동영상이 포함되어 있다. 이처럼 동영상은 정보교환과 정보표현의 매개물로서 중요한 역할을 한다. 그러나 이와 같은 동영상은 노이즈나 전송과정 중 발생하는 문제 등으로 인해 항상 좋은 품질을 보장되지 않는다. 이런 훼손된 영상을 원영상으로 복원하거나 사용자가 제거 혹은 복원하고자 하는 영역을 지정 처리함으로서 다양한 정보를 획득할 수 있다. 일반적으로 pc에서 사용되어지는 대부분의 동영상은 $15fps{\sim}30fps$이다. 대부분의 동영상 편집 기술은 각각의 frame을 추출하여 수동적으로 처리하므로 비용과 시간이 많이 든다. 이런 단점을 해결하기 위해 여러 방법이 기존에 시도되고 있다. 제거 혹은 복원하고자 하는 영역을 전 frame에서 처리하기 위해 움직임 검출 및 추적기법이 사용되며, 제거 혹은 복원하기 위해 median filtering, image inpainting 처리 방법들이 있다. 본 연구에서는 사용자에 의해 미리 정의된 바운딩 박스내의 객체를 추적하여 객체의 중심값을 찾는 mean-shift algorithm을 이용하여 움직이는 객체를 추적하였고 image Inpainting algorithm을 이용하여 훼손된 영역을 복원하거나 제거하고자 하는 객체를 제거하였다.