• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.310-319
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• 2016

This paper proposes an effective FRUC (Frame Rate Up-Conversion) technique, which is based on ROI (Region Of Interest) separations and adaptive motion vector refinement. In this paper, in order to overcome the weakness of the EBME (Extended Bi-lateral Motion Estimation) algorithm, which is widely known in FRUC techniques, first, the proposed algorithm performs a bi-directional motion estimation for the complementary asymmetric region. Then, the proposed algorithm classifies each block into ROI or non-ROI block and refine motion vectors in accordance with their block characteristics to have a higher accuracy than the conventional EBME algorithm, specially, for the occlusion regions. The experimental results show that the proposed algorithm can improves 0.59dB on average PSNR as compared to the conventional method.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.671-675
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• 2011

DVC (Distributed Video Coding) and FRUC (Frame Rate Up Conversion) techniques need to have an efficient motion compensated frame interpolation algorithms. Conventional works of these applications have mainly focused on the performance improvement of overall system. But, in some applications, it is necessary to evaluate how well the MCI (Motion Compensated Interpolation) frame matches the original frame. For this aim, this paper deals with the modeling methods for evaluating the block-based matching cost. First, several matching criteria, which have already been dealt with the motion compensated frame interpolation, are introduced and then combined to make estimate models for the size of MSE (Mean Square Error) noise of the MCI frame to original one. Through computer simulations, it is shown that the block-based matching criteria are evaluated and the proposed model can be effectively used for estimating the MSE noise.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.28-36
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• 2013

Motion-compensated frame interpolation (MCFI) techniques in video signal processing have many application areas. Frame rate up-conversion (FRUC) or distributed video coding (DVC) technique needs an effective MCFI algorithm. For these applications, it is necessary to develop an effective post-processing technique to improve visual qualities or to reduce virtual channel noises, resulting in the reduced channel bit rate. This paper proposes a reliability evaluation method based on spatio-temporal characteristics for motion-compensated interpolated blocks. The proposed algorithm investigates the temporal matching characteristics for current frame and then is designed in such a way that it can measure temporal characteristics as well as the spatial ones. Through computer simulations, it is shown that the proposed method outperforms the conventional temporal matching method.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.85-91
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• 2015

This paper presents a novel frame rate up-conversion (FRUC) algorithm. Existing algorithms, in general, employ rectangular blocks for motion estimation and arbitrary shape of an actual object region cannot be precisely represented. On the other hand, the proposed wedge-shaped block partitioning algorithm partitions a rectangular block into two wedge-shaped blocks using the texture information, which makes better approximation for an actual object region. The wedge-shaped block partitioning algorithm as well as the adaptive motion vector prediction algorithm is used to reliably estimate the actual motion. Experimental results show that the proposed FRUC algorithm is superior to existing algorithms up to 1.988dB in PSNR and 0.0167 in SSIM comparisons.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.47-53
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• 2007

True motion estimation is necessary for deinterlacing, frame-rate conversion, and film judder compensation. There have been several block-based approaches to find true motion vectors by tracing minimum sum-of-absolute-difference (SAD) values by considering spatial and temporal consistency. However, the algorithms cannot find robust motion vectors when the texture of objects is changed. To find the robust motion vectors in the region, a recursive vector selection scheme and an adaptive weighting parameter are proposed. Previous frame vectors are recursively averaged to be utilized for motion error region. The weighting parameter controls fidelity to input vectors and the recursively averaged ones, where the input vectors come from the conventional estimators. If the input vectors are not reliable, then the mean vectors of the previous frame are used for temporal consistency. Experimental results show more robust motion vectors than those of the conventional methods in time-varying texture objects.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.164-166
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• 2012

최근 스마트 기기의 보급과 무선 인터넷망의 보급으로 언제 어디에서나 비디오를 시청할 수 있다. 하지만 무선 인터넷 망의 품질이 안좋을 경우 영상의 QoS(Quality of Service)를 낮춰 프레임을 스킵하여 전송하게 된다. 이 때 FRUC(Frame Rate Up Conversion)기술을 적용한다면 원본의 프레임 레이트를 확보할 수 있어 QoS를 높일 것으로 기대한다. FRUC에서 MV(Motion Vector)추정시에 연산량이 매우 높아서 스마트 기기에 적용하는 것이 어렵지만 H.264코덱으로 인코딩된 동영상은 자체적으로 MV정보를 갖고 있기 때문에 이 MV를 FRUC에 적용할 수 있다면 FRUC의 연산량을 줄일 수 있을 것이다. 이를 위해서 H.264에 적용된 ME(Motion Estimation)와 FRUC에 적용된 ME의 차이를 고려하여 H.264코덱의 MV가 유용한지 분석하는 것이 선행돼야 한다. 본 논문에서는 H.264 MV와 FRUC의 MV의 차이를 분석하고 유용성을 판단하는 실험을 통해 H.264로 인코딩 된 비디오의 MV중 상당수가 FRUC에 적합함을 확인했다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.613-616
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• 2010

본 논문에서는 새로운 움직임 추정(motion estimation, ME) 방식을 사용한 프레임 비율 변환(frame rate conversion, FRC) 기법에 대해 제안한다. 기존의 프레임 비율 변환을 위한 움직임 추정 방식은 영상 압축에서 사용되고 있는 SAD를 사용하여 블록(block) 단위로 움직임 벡터를 추정하는 방식에 기초를 두고 있다. 그러나 잔여 신호(residual signal)를 저장하는 영상 압축과 달리, 잘못된 움직임 추정은 합성된 출력 영상에서 심각한 품질 저하를 가져올 수 있다. 이를 보완하기 위해 움직임 개선(motion refinement, MR)이 사용되고 있지만, 근본적인 해결을 위해서는 정확한 움직임 추정 알고리즘 사용이 필요하다. 특히 SAD를 통한 움직임 추정은 고르지 못한 움직임 벡터장(motion vector field, MVF)을 형성할 수 있으며, 종래의 연구에서 이를 해결하기 위해 SAD(sum of absolute difference)에 벡터의 공간제약(spatial constraint) 항목을 추가하여 비교적 고른 움직임 벡터장을 형성하는 방식이 제시되었다. SAD와 공간 제약 항목의 반영 비율에 따라 움직임 벡터의 중요성과 움직임 벡터장의 일관성이 서로 상충하는데, 기존의 방식은 이 비율을 일정한 상수(constant)값을 사용하고 있으며, 이러한 방식은 이미지의 특성에 따라 결과가 달라진다. 본 논문에서는 SAD와 공간 제약 항목 사이의 반영 비율을 이미지의 특성에 적응하는 방식을 사용하는 움직임 예측을 제시하고, 수행한 결과를 기존의 방식에 의한 결과와 비교하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.598-604
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• 2008

The hold-type display panel such as a liquid crystal displays(LCD) has problem of motion blur. The problem can be improved by a Frame Rate-up Conversion(FRC) using a frame interpolation. We propose a Motion Estimation(ME) by using adaptively expanded block based on frame difference for PRC. The proposed method is executed using an adaptively expanded block in order to get more accurate motion vector. By using frame difference, we can reduce complexity more significantly than conventional methods. We use quantitative analysis in order to evaluate experimental results. The results show that the proposed method has better performance and lower complexity than conventional methods.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.1-8
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• 2012

Video FRUC (Frame Rate Up Conversion) has been a technique of great interest due to its diversified applications in consumer electronics. Most advanced FRUC algorithms adopt a motion interpolation technique to determine the motion vector field of interpolated frames. But, in some applications, it is necessary to evaluate how well the MCI (Motion Compensated Interpolation) frame is reconstructed. For this aim, this paper proposes a distortion estimation for motion compensated interpolation frame using frame-adaptive distortion estimation. The proposed method is applied for the symmetric motion estimation and compensated scheme and then analyzed by three different approaches, that is, forward estimation, backward estimation and adaptive bi-directional estimation schemes. Through computer simulations, it is shown that the proposed bi-directional estimation method outperforms others and can be effectively applied for FRUC.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.90-92
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• 2014

본 논문에서는 피라미드 구조와 쿼드트리를 이용하는 움직임 보상 프레임 보간(motion compensated frame interpolation, MCFI)의 새로운 방법을 제안한다. 일반적인 MCFI 방법에서는 고정된 크기의 프레임과 블록에서 움직임 벡터(motion vector, MV)를 이용하여 두 프레임 사이의 프레임 영상을 추정한다. 그러나 이와 같은 방법은, 큰다양한 방향으로 움직이는 물체들의 MV 나 큰 움직임을 추정하기 어렵다. 이러한 문제점을 해결하기 위해서 본 논문에서는 블록 크기와 정합 영역이 가변적으로 적용될 수 있는 피라미드 구조와 쿼드트리를 이용한 프레임 보간 기법(pyramid structure and quadtree motion compensated frame interpolation, PQ-MCFI)를 제안한다. 제안하는 기법은 물체들이 빠르게 움직이는 장면과 다양한 방향으로 움직이는 장면에서 이전의 기법에 비해서 높은 PSNR 을 보이며, 실제 인간의 시각적인 측면에서는 더욱 정밀한 결과를 보인다.