• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.21-25
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• 1999

Wavelet transform decomposes a video frame into a set of subframes with different resolutions corresponding to different frequency bands. The block size of highest layer subframe is too small to estimate correct motion. To decrease this aperture problem in the approximation frame, multiresolution motion estimation (MRME) using hierarchical block matching is presented in this paper. In the multiresolution motion estimation approach, motion vectors in the subframes are estimated by the motion vectors in the approximation frame and are refined at each subframe. It reduces computational time in motion estimation. It is shown that our MRME approach has a superior performance than traditional MRME approaches.

• Journal of Information Technology Applications and Management
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• v.10 no.3
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• pp.45-54
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• 2003

Security system with web camera remarkably has been developed at an Internet era. Using transmitted images from remote camera, the system can recognize current situation and take a proper action through web. Existing motion detection methods use simply difference image, background image techniques or block matching algorithm which establish initial block by set search area and find similar block. But these methods are difficult to detect exact motion because of useless noise. In this paper, the proposed method is updating changed background image as much as $N{\times}M$pixel mask as time goes on after get a difference between imput image and first background image. And checking image pixel can efficiently detect motion by computing fixed distance pixel instead of operate all pixel.

• Journal of the Korea Computer Industry Society
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• v.4 no.10
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• pp.761-767
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• 2003

In this paper, A Fast Multi-level Successive Elimination Algorithm (FMSEA) is presented for block matching motion estimation in video coding. Motion estimation accuracy of FMSEA is equal to that of Multilevel Successive Elimination Algorithm(MSEA). FMSEA can reduce the computations for motion estimation of MSEA by using partial distortion elimination technique. The efficiency of the proposed algorithm was verified by experimental results.

• Journal of Korea Multimedia Society
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• v.2 no.3
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• pp.243-251
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• 1999

In this paper, we suggest a novel method which defines index for effectively searching MPEG video data. The traditional methods are slow because they rely on pattern matching of images between extracted shots and user's querying images. Whereas, our method uses a different approach: It transforms images of extracted PFrames into codes and uses the codes for creating index keys. To be specific, we define five features of non-context description for transparency about user's querying.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.987-992
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• 2004

There is the temporal correlation of the video sequence between the motion vector of current block and the motion vector of previous block. In this paper, we propose the improved diamond search pattern using an motion vector prediction candidate search point by the predicted motion information from the same block of the previous frame. Simulation results show that PSNR(Peak-to-Signal Noise Ratio) values are improves as high as high as 14~24% in terms of average number of search point per motion vector estimation and improved about 0.02~0.37dB on an average except the full search(FS) algorithm.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.605-606
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• 2008

The distance detection system receives stereo video input through 2 CCD cameras. Using a decoder, the image is changed to the YCbCr4:2:2 format and only the Y signal is saved in the 4*256*8bit shift register of the Dual-Port SRAM. As a result of the matching procedure, the Depth value, which is the distance information, is saved in SRAM, and the Depth Map is made and output to the TFT-LCD screen.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.783-784
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• 2008

Block-matching motion estimation plays an important role in video coding. In this paper, we propose fast motion estimation algorithm using octagon pattern for low complexity. Proposed algorithm carries out minimum SAD point among nine regions divided by octagon pattern and center point. Experimental results show that proposed algorithm has better performance than conventional method through quantitative analysis.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.275-280
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• 2004

In this paper, a very fast block matching scheme was proposed to reduce the computations of Block Sum Pyramid Algorithm for motion estimation in video coding. The proposed algorithm is based on Block Sum Pyramid Algorithm and Efficient Multi-level Successive Elimination Algorithm. The proposed algorithm can reduce the computations of motion estimation greatly with 100% motion estimation accuracy. The efficiency of the proposed algorithm was verified by experimental results.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.604-606
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• 2001

최근 들어 이미지 모자익은 가상현실과 웹 브라우저 상에서의 가상환경 구축, 관광, 광고 등, 많은 응용분야에서 관심을 모으고 있다. 이미지 모자익을 위해 해결해야 할 주된 문제는 이미지들 간의 중복되는 영역에서 정확한 대응점을 찾는 것이다. 지금까지 이 대응점을 찾기 위한 노력은 시스템의 많은 계산량과 시간을 투자해야만 했다. 또한 대부분의 모자익이 여러 차례의 촬영에 의한 정지 화상들 간의 모자익에 그치고 있다. 따라서 본 논문에서는 비디오 카메라를 이용하여 프레임들 간의 중복되는 영역에서 일정한 비교 영역을 지정하고 그 비교 영역 안에서 대응점을 찾는 블럭 매칭 방법을 적용함으로써 전체적인 모자익 시간을 줄이는 방법을 구현하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.613-615
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• 2001

본 논문은 동영상 내의 얼굴을 특정인 얼굴로 자동 변환 및 정합하는 기술을 제안한다. 얼굴에 나타난 동작이나 표정은 높은 자유도로 인하여 기존에 사용되어온 2차원적이고 고정된 물체 위주의 동영상 정합 기술로는 자연스러운 결과물을 얻기가 어렵다. 본 논문에서는 입력 받은 정면 유사방향의 사진으로부터 3차원 얼굴 모델을 복원한다. 각 프레임에 등장한 얼굴의 3차원 방향을 추출하여 복원한 3차원 얼굴 모델에 적용한 후 대체할 얼굴 영역에 저합시킨다. 정합 과정 시 비디오 프레임 내의 조명효과와 얼굴색 등을 분석하고 3차원 얼굴 모델에 블렌딩하여 비디오 프레임과 자연스럽게 정합할 수 있도록 한다.