• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.51-57
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• 2017

Digital signage is becoming part of daily life across a wide range of visual advertisements segments market used in stations, hotels, retail stores, hotels, etc. The current digital signage system used in market is generally works on limited user interactivity with static contents. In this paper, a new approach is proposed using computer vision based dynamic audience adaptive cost-effective digital signage system. The proposed design uses the Camera attached Raspberry Pi Open source platform to employ the real-time audience interaction using computer vision algorithms to extract facial features of the audience. The real-time facial features are extracted using Haar Cascade algorithm which are used for audience gender specific rendering of dynamic digital signage content. The audience facial characterization using Haar Cascade is evaluated on the FERET database with 95% accuracy for gender classification. The proposed system, developed and evaluated with male and female audiences in real-life environments camera embedded raspberry pi with good level of accuracy.

• Journal of KIISE
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• v.43 no.4
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• pp.399-403
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• 2016

Deferred Shading is a shading technique that postprocesses pixels in the screen space, following geometry-only rendering passes with depth buffering. Unlike typical shadow mapping techniques, this technique allows us to render shadows from multiple light sources without changing the structure of the rendering pipelines. This paper presents a deferred shadow mapping technique and its extension to soft shadows using mipmapping. Our technique first generates visibility maps from light sources, and blurs the visibility maps for deferred shading. This strategy leads to efficient soft-edged shadows, but does not incorporate depth variation, producing light bleeding to some extent. In order to suppress the light-bleeding artifacts, we also propose a depth-adaptive mipmap sampling technique in the screen space.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.113-121
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• 2013

In this paper, we propose a sub-pixel rendering algorithm using learning-based 2D FIR filters. The proposed algorithm consists of two stages: the learning and synthesis stages. At the learning stage, we produce the low-resolution synthesis information derived from a sufficient number of high/low resolution block pairs, and store the synthesis information into a so-called dictionary. At the synthesis stage, the best candidate block corresponding to each input high-resolution block is found in the dictionary. Next, we can finally obtain the low-resolution image by synthesizing the low-resolution block using the selected 2D FIR filter on a sub-pixel basis. On the other hand, we additionally enhance the sharpness of the output image by using pre-emphasis considering RGB stripe pattern of display. The simulation results show that the proposed algorithm can provide significantly sharper results than conventional down-sampling methods, without blur effects and aliasing.

• Journal of the Korea Computer Graphics Society
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• v.24 no.5
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• pp.21-30
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• 2018

In this paper, we use Sound-tracing, a 3D sound technology based on ray-tracing that uses geometric method as auditory technology to enhance realism. The Sound-tracing is costly in the sound propagation stage. In order to reduce the sound propagation cost, we propose a method to calculate the average effective frame number of previous frames using the frame coherence property and to adjust the depth according to the space based on the calculated number. Experimental results show that the path loss rate is 0.72% and the traversal & Intersection test calculation amount is decreased by 85.13% and the frame rate is increased by 4.48% when the sound source is indoors, compared with the result of the case without depth control. When the sound source was outdoors, the path loss was 0% and the traversal & Intersection test calculation amount is decreased by 25.01% and the frame rate increased by 7.85%. This allowed the rendering performance to be increased while minimizing the path loss rate.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.1-13
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• 2012

3D video is regarded as the next generation contents in numerous applications. The 2D-to-3D video conversion technologies are strongly required to resolve a lack of 3D videos during the period of transition to the full ripe 3D video era. In 2D-to-3D conversion methods, after the depth image of each scene in 2D video is estimated, stereoscopic video is synthesized using DIBR (Depth Image Based Rendering) technologies. This paper proposes a novel depth fusion algorithm that integrates multiple depth cues contained in 2D video to generate stereoscopic video. For the proper depth fusion, it is checked whether some cues are reliable or not in current scene. Based on the result of the reliability tests, current scene is classified into one of 4 scene types and scene-adaptive depth fusion is applied to combine those reliable depth cues to generate the final depth information. Simulation results show that each depth cue is reasonably utilized according to scene types and final depth is generated by cues which can effectively represent the current scene.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.06a
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• pp.149-150
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• 2017

본 논문에서는 RGB-stripe 부화소 구조를 갖는 디스플레이에서 인지 화질을 향상시키면서, 색 왜곡을 저감할 수 있는 부화소 렌더링을 수행한다. 우선 인지 화질을 향상 시키는 주 필터와, 색 왜곡을 억제하는 비음수 필터를 디자인한다. 색 왜곡 가능성의 계산에 따라, 두 필터를 조합하고 영상을 렌더링 한다. 실험 결과, 본 논문의 부화소 렌더링 방법이 비교 방법에 비해 좋은 인지 화질을 얻으면서도 색 왜곡을 억제함을 보여준다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.107-108
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• 2014

부화소 기반 영상 축소기법은 각각의 부화소를 조절함으로써 픽셀 기반 영상 축소기법보다 해상도를 향상시킬 수 있는 방법이다. 그러나 부화소에 의한 해상도의 증가는 종종 색상정보의 왜곡을 발생시킨다. 부화소 랜더링의 주요과제는 선명도를 유지함과 동시에 색조왜곡현상을 억제하는 것이다. 선행연구들은 부화소랜더링을 위해 1 차원 혹은 2 차원 필터를 최적화 하였지만, 지역적인 특성을 고려하지 않았기 때문에 출력영상의 화질이 저하되는 현상이 발생한다. 본 논문은 위와 같은 문제를 해결하기 위해 내용적응형 2D FIR 필터를 제작방법을 제안한다. 제안필터는 충분한 수의 저해상도 패치와 고해상도 패치 쌍을 이용하여 임의의 고해상도 패치로부터 고화질의 저해상도 패치를 만들기 위한 최적의 내용적응형 2D FIR 필터를 학습한다. 학습된 필터에 의한 실험결과 제안하는 필터가 종례기법들 보다 색조왜곡현상이 현저히 줄어들고, 출력영상의 선명도를 유지함을 보여준다.

• Journal of the Korea Computer Graphics Society
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• v.12 no.2
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• pp.19-25
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• 2006

정보생물학 분야에 있어서 분자 구조를 3차원으로 렌더링하여 보여주는 것은 매우 중요한 작업이다. 특히 분자의 표면 렌더링은 분자의 3차원 구조 분석 등에 중요하게 사용된다. 그러나 분자 표면 렌더링을 수행하기 위해서는 많은 양의 폴리곤이 필요하게 된다. 대장균 바이러스와 같은 분자량이 많은 거대 분자를 자연스럽게 렌더링 하기 위해서는 고성능이며 고가의 그래픽 전용 워크스테이션을 사용해야 한다. 본 논문에서는 PC급 시스템에서도 거대 분자를 무리 없이 렌더링 할 수 있는 효율적인 알고리즘을 제안 하였다. 제안하는 알고리즘은 사용자의 시점에서 최적의 성능 및 시각적인 기여를 할 수 있는 적응형 상세 단계 렌더링을 수행한다. 제안된 알고리즘을 사용하여 거대 분자 모델의 렌더링시 대화식 프레임 수준이상의 성능향상을 보이며, 또한 시각적으로도 분자 모델이 가진 중요한 기하학적인 특성을 유지 할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2C
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• pp.112-118
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• 2011

In this paper, we conduct an objective performance analysis of the crosstalk cancellation scheme studied in [11]. While the conventional scheme is only applicable to a listener on the optimal listenable region (sweetspot), the space skew/crosstalk cancellation (SS/CC) scheme in [11] can mitigate crosstalk regardless of the listener's position by using listener position tracking (LPT) system. The SS/CC scheme is composed of two parts: LPT-based SS and CC parts. In this paper, the SS/CC scheme is evaluated by some criteria such as follows: condition number, and the balance characteristic, its root mean square error, and running average.

• Journal of Korea Game Society
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• v.7 no.2
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• pp.21-32
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• 2007

It is significant to simulate scattering of light within media for realistic image synthesis; however, this requires costly computation. This paper introduces a practical image-space approximation technique for interactive subsurface scattering. We use a general two-pass approach, which creates transmitted irradiance samples onto shadow maps and computes illumination using the shadow maps. We estimate single scattering efficiently using a method similar to common shadow mapping with adaptive deterministic sampling. A hierarchical technique is applied to evaluate multiple scattering, based on a diffusion theory. We further accelerate rendering speed by tabulating complex functions and utilizing level of detail. We demonstrate that our technique produces high-quality images of animated scenes with blurred shadow at hundreds frames per second on graphics hardware. It can be integrated into existing interactive systems easily.