• 디지털콘텐츠학회 논문지
• /
• 제9권3호
• /
• pp.433-439
• /
• 2008

온라인 게임에서 동영상은 게임을 홍보하는 중요한 수단이며, 게임 진행에 많은 도움을 준다. 이 경우에 동영상은 저장 공간의 효율적인 사용과 네트워크 자원의 효율성을 위해 가변 비트율 형태로 압축된다. 적응형 대역폭 할당은 게임 동영상에 대한 전송 계획을 세우고 이 계획에 의한 전송률이 가용 전송률보다 큰 경우에 가용 전송률을 만족시킬 때까지 일부 프레임을 폐기시켜서 전송하는 방법이다. 이때, 적응형 대역폭 할당 방법에서의 평가 요소들은 전송률을 설정하는데 크게 영향을 준 프레임들의 폐기 순서에 따라 크게 달라질 수 있다. 본 논문에서는 이를 살펴보기 위하여 전송 계획에 사용되는 CBA, MCBA, MVBA, [6]], [7]의 알고리즘들을 적응형 대역폭 할당 방법의 전송 계획으로 각각 적용하여 다양한 프레임 폐기 방법들로 성능을 평가한다.

• 한국멀티미디어학회논문지
• /
• 제15권8호
• /
• pp.977-985
• /
• 2012

본 연구에서는 단일영상과 동영상에서의 효율적인 비사실적 렌더링 기법을 제안한다. 단일영상의 경우에는 최근 단일영상 NPR 기법에서 많이 사용되는 플로우 기반 DoG 필터와 Bilateral 필터를 CUDA 환경에서 구현하여 실시간 처리가 가능하게 한다. 또한 동영상의 경우에는 기존의 NPR 동영상 방법인 매 프레임마다 단일영상 NPR 기법을 적용하여 생성하는 방법이 아닌 첫 프레임은 단일영상에 적용되는 NPR기법을 사용하여 스타일화 하고, 다음 프레임부터는 움직임 벡터를 기반으로 한 픽셀 맵핑을 사용하여 이전 프레임에서 움직임이 있는 픽셀의 밝기 값을 다음 프레임의 움직임 벡터 위치로 복사함으로써 불필요한 계산량을 줄이고, 프레임 간의 일관성 또한 유지시키는 방법을 제안한다. 본 연구에서는 실험을 통하여 그 성능을 증명하였다.

• ETRI Journal
• /
• 제23권4호
• /
• pp.190-198
• /
• 2001

The performance of Motion Compensated Discrete Cosine Transform (MC-DCT) video coding is improved by using the region adaptive subband image coding [18]. On the assumption that the video is acquired from the camera on a moving platform and the distance between the camera and the scene is large enough, both the motion of camera and the motion of moving objects in a frame are compensated. For the compensation of camera motion, a feature matching algorithm is employed. Several feature points extracted using a Sobel operator are used to compensate the camera motion of translation, rotation, and zoom. The illumination change between frames is also compensated. Motion compensated frame differences are divided into three regions called stationary background, moving objects, and newly emerging areas each of which is arbitrarily shaped. Different quantizers are used for different regions. Compared to the conventional MC-DCT video coding using block matching algorithm, our video coding scheme shows about 1.0-dB improvements on average for the experimental video samples.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권9호
• /
• pp.3196-3210
• /
• 2014

This paper presents a novel video metrology approach based on robust tracking. From videos acquired by an uncalibrated stationary camera, the foreground likelihood map is obtained by using the Codebook background modeling algorithm, and the multiple moving objects are tracked by a combined tracking algorithm. Then, we compute vanishing line of the ground plane and the vertical vanishing point of the scene, and extract the head feature points and the feet feature points in each frame of video sequences. Finally, we apply a single view mensuration algorithm to each of the frames to obtain height measurements and fuse the multi-frame measurements using RANSAC algorithm. Compared with other popular methods, our proposed algorithm does not require calibrating the camera, and can track the multiple moving objects when occlusion occurs. Therefore, it reduces the complexity of calculation and improves the accuracy of measurement simultaneously. The experimental results demonstrate that our method is effective and robust to occlusion.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.167-169
• /
• 2005

The occurrence of a single bit error in transmission bitstream leads to serious temporal and spatial errors. Because moving picture coding as MPEG-2 based on block coding algorithm uses variable length coding and motion compensation coding algorithm. In this paper, we propose algorithm to conceal occurred error of I-frames in transmission channel using data of the neighboring blocks in decoder. We divide a damaged macroblock of I-frame into four sub blocks and compose new macroblock using the neighboring blocks for each sub block. We estimate the block with minimum difference value through block matching with previous frame for new macroblocks and replace each estimated block with damaged sub block in the same position. Through simulation results, the proposed algorithm will be applied to a characteristic of moving with effect and shows better performance than conventional error concealment algorithms from visual and PSNR of view.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.295-296
• /
• 2006

This paper implements a method that tracking the moving objects that detected by the motion detection function of the digital CCTV system. We simply implement the motion detection function of the digital CCTV system that use frame difference and thresholding. When motion is detected, the motion detection function generates two outputs. One output is the event that the motion is arised in input image frame. The other output is coordinate that motion is exists. Then, do the block matching algorithm[2] using coordinate, that motion is exists, as initial coordinate of the block matching algorithm. The best matched coordinate is new initial coordinate of the block matching algorithm for the next image frame. We simply use the block matching algorithm that implements tracking the moving objects. It is simple, but useful the actual digital CCTV system.

• 전자공학회논문지A
• /
• 제33A권10호
• /
• pp.40-47
• /
• 1996

A method for computing effectiv ebandwidth of aggregated varable bit rate (VBR) moving picture experts group (MPEG) video traffic is proposed. To compute statistical characteristics of aggregated MPEG traffic, first we split input MPEG traffic into I, B, and P frame traffics and aggregate respective I, B, and P frame traffics according to the frame type. Second statisticsal characteristics of the aggregated MPEG traffic are obtained using those of aggregated I, B, and P frame traffics. The effective bandwidth of the aggregated I frame traffic is computed by using the gaussian bound. Using the modified equivalent capacity, we obtain the effective bandwidths of aggregated B and P frame traffics and then compute the effective bandwidth of the combined B and P frame traffic. Finally the effective bandwidth of the aggregated MPEG traffic is computed by adding the gaussian bound of the aggregated I frame traffic and modifed equivalent capacity of combined B and P frame traffic. Computer simulation shows that the proposed method estimates effective bandwidth of the aggregated MPEG traffic well.

• International Journal of Control, Automation, and Systems
• /
• 제1권4호
• /
• pp.495-502
• /
• 2003

This paper focuses on the implementation of an efficient tracking method of a moving object using optimal representative blocks by way of a pan-tilt camera. The key idea is derived from the fact that when the image size of a moving object is shrunk in an image frame according to the distance between the mobile robot camera and the object in motion, the tracking performance of a moving object can be improved by reducing the size of representative blocks according to the object image size. Motion estimations using Edge Detection (ED) and Block-Matching Algorithm (BMA) are regularly employed to track objects by vision sensors. However, these methods often neglect the real-time vision data since these schemes suffer from heavy computational load. In this paper, a representative block able to significantly reduce the amount of data to be computed, is defined and optimized by changing the size of representative blocks according to the size of the object in the image frame in order to improve tracking performance. The proposed algorithm is verified experimentally by using a two degree-of- freedom active camera mounted on a mobile robot.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.903-912
• /
• 2007

Faults of rotating parts of a train normally generate unexpected frequency band or impulsive sound[1] which has a period when it moves with a constant speed. The former can be detected by the moving frame acoustic holography method, which visualizes sound field that is generated by a moving and emitting pure tone or band limited noise source. We have attempted to apply the method to the latter case: the periodic impulsive sound which generate different signal compared with what can be measured by the band limited noise. The signal to noise ratio which determines the success of early fault detection must also be studied with the impulsive and moving signal. This research shows how the problems related with these issues can be resolved. The main idea is that periodic impulsive signal can be expressed by infinite set of discrete pure tones. This enables us to obtain lots of holograms that visualize periodic impulsive sound field including noise by using the moving frame acoustic holography method. Therefore holograms can be averaged to improve the signal to noise ratio until having reliable information that exhibits where the impulsive sources are. Theory and experiment by using the miniature vehicle are described [Work supported by BK21 & KRRI].

• 전자공학회논문지S
• /
• 제36S권1호
• /
• pp.93-103
• /
• 1999

본 논문은 주행중의 자동차에 장착된 카메라의 입력 영상으로부터 이동창을 활용하여 차선을 인식하고 장애물을 감지하는 기법을 기술한다. 영상 정보로부터 장애물을 감지하기 위해서 차선의 위치를 빠른 시간에 추출하는 것이 매우 중요하다. 이를 위하여 한 프레임의 영상에서 차선의 입력이 예상되는 일부분만을 선정하는 기법이 일반적이다. 본 논문에서는 주행 차량의 영상 정보로부터 장애물을 감지하기 위하여, 도로의 곡률에 따라 차선의 입력 예상 위치를 측정하여 크기가 조절된 이동하는 창을 설정하여 정확한 차선의 위치를 추출하고, 나아가 주행 차선 내에 위치하는 장애물을 점출할 수 있는 기법을 제안한다. 이를 고정창을 이용하는 경우와 레이저 혹은 레이터 센서를 사용하는 경우와 비교하여, 정확도가 높음을 보였다.