• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.199-204
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• 2002

Since motion estimation and motion compensation methods remove the redundant data to employ the temporal redundancy in images, it plays an important role in digital video compression. Because of its high computational complexity, however, it is difficult to apply to high-resolution applications in real time environments. If we have information about the motion of an image block before the motion estimation, the location of a better starting point for the search of an exact motion vector can be determined to expedite the searching process. In this paper, we present an adaptive motion estimation approach bated on temporal correlations of consecutive image frames that defines the search pattern and determines the location of the initial search point adaptively. Through experiments, compared with DS(Diamond Search) algorithm, the proposed algorithm is about 0.1∼0.5(dB) better than DS in terms of PSNR(Peak Signal to Noise Ratio) and improves as high as 50% compared with DS in terms of average number of search point per motion vector estimation.

• Broadcasting and Media Magazine
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• v.25 no.3
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• pp.68-83
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• 2020

1990년대말, 한국은 북미 ATSC 방송표준을 사용하여, 세계최초 HD Digital TV 방송시대를 시작하였고, 이동방송을 위해서는 DMB를 이용한 모바일 방송을 상용화하여, 이는 디지털 방송미디어 산업의 발전과 함께 글로벌 기술 경쟁력을 만드는 계기가 되었다. 이후, 20여년이 지난 최근, 한국은 북미 최신 방송표준기술인 ATSC3.0을 세계 최초로 국내에 상용화하여 4K UHD 지상파 방송시대를 여는 성과를 또다시 이루었다. 하지만, 그동안 통신기술의 눈부신 발달로 고해상도 몰입형 컨텐츠의 IP 스트리밍 서비스가 대중화되었고, 이에 따른 젊은 소비자들을 중심으로 미디어 소비 성향 변화가 확산되어, 이제는 새로운 형태의 미래 융합 방송미디어 서비스를 위한 기술과 정책이 요구되고 있다. 이에, 정부는 관련 산학연 전문가들과 2027년 ATSC3.0 UHD로의 모든 전환 정책을 위해서 다양한 요구사항을 고려한, 미래형 모바일 방송을 포함한 UHD 활성화 방안을 논의하고 있다. 미래형 모바일 방송은 스마트폰뿐만 아니라, 자동차와 사이니지, 홈 TV에서도 서비스 영역이 확장되어야 하며, IP와 연동하여 인터렉티브 양방향 서비스가 가능하여야 하고, 오디오, 비디오 엔터테인먼트뿐만 아니라 인터넷 데이터와 공공, 관심 정보의 데이터 캐스팅 서비스까지 가능하여야 한다. 본 고에서는 미래형 모바일 방송을 위하여, 현재 상용 서비스가 가능한 최신의 방송과 통신기술인 ATSC3.0과 5G를 통한 방송의 서비스와 기술에 대하여 살펴보고, 이들의 미래융합 서비스의 가능성에 대하여 생각해 보는 기회를 삼고자 한다. 본 고의 구성은 서론에서는 방송미디어의 서비스 트렌드를 분석하여 모바일 방송의 복합적 요구사항을 도출해 보고, 본론에서는 현재, 한국의 지상파 UHD 방송표준 기술인 ATSC3.0의 이동방송으로서의 특성을 살펴보고, DMB 기술과 비교해 본다. 또한, 전세계적으로 관심과 실험이 시작되고 있는 5G 방송에 대해서도 그 내용과 동향을 살펴보았다. 그리고, 결론으로는 미래의 융합서비스에 대한 예측과 연구사항에 대하여 생각해 본다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.766-772
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• 2007

H.264/AVC is a new international standard for the compression of video images, in which a deblocking filter has been adopted to remove blocking artifacts. This paper proposes an efficient architecture of deblocking filter in H.264/AVC. By making good use of data dependence between neighboring $4{\times}4$ blocks, the memory size is reduced and the throughput of the deblocking filter processing is increased. Compared to the conventional deblocking filters, the proposed architecture enhances the performance of deblocking filter processing from 1.75 to 4.23 times. Hence the proposed architecture is able to perform real-time deblocking of high-resolution($2048{\times}1024$) video applications.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.3
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• pp.21-29
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• 2000

In this paper, we propose a way to detect a moving object efficiently and to track it using the active blocks. Instead of all Pixels in 8*8 Pixel value, any special pixel is extracted and we detect a moving object by comparison and by analysis the difference image information from darkness value of the same area. In the acquisition of image data by software processing, we reduce the number of data which obtain by convert high resolution image to low resolution image, and we can track a moving object in real time. So it can track a moving object in simple system without all the pixel value of the image data or additional VxD(Virtual x Driver). This system can be useful to track of a moving object in fixed block on PC(Personal Computer) and low custom.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.68-77
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• 2009

A single field deinterlacing method, namely interpolation algorithm derived from low resolution (ILR), is presented in this paper. Traditional deinterlacing methods usually employ edge-based interpolation technique within pixel-based estimation. However, edge-based methods are somehow sensitive to noise and intensity variation in the image. Moreover, the methods are not satisfied in deciding the exact edge direction which controls the performance of the interpolation. In order to reduce the sensitivity, the proposed algorithm investigates low-resolution characteristics of the pixel to be interpolated, and applies it to high-resolution image. Simulation results demonstrates that the proposed method gives not only a better objective performance in terms of PSNR results compare to conventional edge-based interpolation methods, but also better subjective image quality.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.7
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• pp.39-49
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• 2012

Demand for high resolution video services leads to active studies on high speed video processing. Especially, widespread deployment of multi-core systems accelerates researches on high resolution video processing based on parallelization of multimedia software. Previously proposed parallelization approach could improve the decoding performance. However, some parallelization methods did not consider the entropy decoding and others considered only a partial decoding parallelization. Therefore, we consider parallel entropy decoding integrated with other parallel video decoding process on a multi-core system. We propose a novel parallel decoding method called Integrated Parallelization. We propose a method on how to optimize the parallelization of video decoding when we have a multi-core system with many cores. We parallelized the KTA 2.7 decoder with the proposed technique on an Intel i7 Quad-Core platform with Intel Hyper-Threading technology and multi-threads scheduling. We achieved up to 70% performance improvement using IP method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.48-56
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• 2010

Recently, we need to dramatically speed up real-time video encoding and decoding on mobile devices because complexity of video CODEC is significantly increasing along with the demand for multimedia service of high-quality and high-definition videos by users. A variety of research is conducted for parallelism of video processing using newly developed multi-core platforms. In this paper, we propose a method of parallelism based on slice partition of video compression CODEC. We propose a novel concept of a parallel slice for parallelism and propose a new coding order to be adequate to the parallel slice which keeps high coding efficiency. To minimize synchronization time of multiple parallel slices, we also propose a synchronization method to determinate whether the parallel slice could be independently decoded or not. Experimental results shows that we achieved 27.5% (40.7%) speed-up by parallelism with bit-rate increase of 3.4% (2.7%) for CIF sequences (720p sequences) by implementing the proposed algorithm on the H.264/AVC.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.687-693
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• 2010

Background: It is controversial whether the presence of bullae on the contralateral lung on HRCT plays a role in occurrence of contralateral primary spontaneous pneumothorax. We analyzed the significance of bullae on the contralateral lung and the risk factors associated with contralateral occurrence of primary spontaneous pneumothorax. Material and Method: Three hundred ninety four patients who were undergone Video-Assisted Thoracoscopic Surgery for primary spontaneous pneumothorax between January 2004 and December 2009 were reviewed. The clinical features, HRCT and treatment of these patients were analyzed retrospectively. Result: Twenty eight of 394 patients had contralateral occurrence (7.10%). The average time was $13.06{\pm}9.79$ months. A presence of contralateral bullae of lung on HRCT may not seem to be significant for occurrence of contralateral primary spontaneous pneumothorax (p=0.059). But bullae numbers were much more in contralateral pneumothorax patients (p=0.011). Younger than 20, being underweight (Body Mass Index < $18.5 kg/m^2$) are independent risk factors for contralateral occurrence (odds ratio, 5.075 (1.679~5.339), 2.366 (1.048~5.339) respectively). Conclusion: The presence of bullae on the contralateral lung on HRCT was not significantly influenced the occurrence of contralateral primary spontaneous pneumothorax. However, age, body mass index, and the number of bullae were significant factors for the contralateral pneumothorax. We suggest that those high risk patients may require special attentions and general supportive care to prevent occurrence of contralateral primary spontaneous pneumothorax during the follow-up.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.907-909
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• 2005

체감형 게임의 재미를 극대화 하기 위해서 몰입감있는 게임화면이 제공되어야 한다. 곡면, 반구형 스크린은 일반 평면 스크린을 사용할 때 보다 더 높은 몰입감을 줄 수 있지만 투사시 생기는 왜곡영상 보정에 많은 계산이 요구되는 문제가 있다. 정지된 영상(프리젠테이션 화면)이나 비디오 영상은 메모리 버퍼링을 통해 시스템이 요구하는 속도를 보장할 수 있으나, 사용자와 상호작용이 요구되는 게임에서는 사용자의 반응을 처리한 후 매 프레임 마다 빠른 워핑(warping) 처리를 요구하게 되는데, 렌더링될 화면을 미리 보정할 수가 없기 때문에 시스템 처리속도 저하의 원인이 된다. 본 논문에서는 체감형 게임을 곡면에 투사하는 방법과 GPU를 이용한 빠른 영상 보정을 제안함으로써 게임에서 요구하는 처리 속도를 보장하고 고해상도의 게임화면을 사용할 수 있도록 했다. 웹카메라를 이용하여 스크린과 프로젝터될 영상간의 호모그래피(homographpy)를 정의해서 워핑했고 워핑 연산을 HLSL로 작성하여 GPU를 이용했다. 실험결과로 반구형 스크린에서 몰입감 있는 AR 탁구게임을 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4A
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• pp.239-249
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• 2012

Recently, the virtual view generation method using depth data is employed to support the advanced stereoscopic and auto-stereoscopic displays. Although depth data is invisible to user at 3D video rendering, its accuracy is very important since it determines the quality of generated virtual view image. Many works are related to such depth enhancement exploiting a time-of-flight (TOF) camera. In this paper, we propose a fast 3D scene capturing system using one TOF camera at center and two high-resolution cameras at both sides. Since we need two depth data for both color cameras, we obtain two views' depth data from the center using the 3D warping technique. Holes in warped depth maps are filled by referring to the surrounded background depth values. In order to reduce mismatches of object boundaries between the depth and color images, we used the joint bilateral filter on the warped depth data. Finally, using two color images and depth maps, we generated 10 additional intermediate images. To realize fast capturing system, we implemented the proposed system using multi-threading technique. Experimental results show that the proposed capturing system captured two viewpoints' color and depth videos in real-time and generated 10 additional views at 7 fps.