• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.24-32
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• 2006

본 논문에서는 다시점 카메라부터 획득된 부분적인 3D 점군을 사용하여 실내환경의 3D 복원을 위한 새로운 방법을 제안한다. 지금까지 다양한 양안차 추정 알고리즘이 제안되었으며, 이는 활용 가능한 깊이 영상이 다양함을 의미한다. 따라서, 본 논문에서는 일반화된 다시점 카메라를 이용하여 실내환경을 복원하는 방법을 다룬다. 첫 번째, 3D 점군들의 시간적 특성을 기반으로 변화량이 큰 3D 점들을 제거하고, 공간적 특성을 기반으로 주변의 3D 점을 참조하여 빈 영역을 채움으로써 깊이 영상 정제 과정을 수행한다. 두 번째, 연속된 두 시점에서의 3D 점군을 동일한 영상 평면으로 투영하고, 수정된 KLT (Kanade-Lucas-Tomasi) 특징 추적기를 사용하여 대응점을 찾는다. 그리고 대응점 간의 거리 오차를 최소화함으로써 정밀한 정합을 수행한다. 마지막으로, 여러 시점에서 획득된 3D 점군과 한 쌍의 2D 영상을 동시에 이용하여 3D 점들의 위치를 세밀하게 조절함으로써 최종적인 3D 모델을 생성한다. 제안된 방법은 대응점을 2D 영상 평면에서 찾음으로써 계산의 복잡도를 줄였으며, 3D 데이터의 정밀도가 낮은 경우에도 효과적으로 동작한다. 또한, 다시점 카메라를 이용함으로써 수 시점에서의 깊이 영상과 컬러 영상만으로도 실내환경 3D 복원이 가능하다. 제안된 방법은 네비게이션 뿐만 아니라 상호작용을 위한 3D 모델 생성에 활용될 수 있다.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.327-336
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• 1999

Purpose: To assess the quantitative accuracy and the clinical utility of 3D volumetric PET imaging with FDG in brain studies, 24 patients with various neurological disorders were studied. Materials and Methods: Each patient was injected with 370 MBq of 2-[$^{18}F$]fluoro-2-deoxy-D-glucose. After a 30 min uptake period, the patients were imaged for 30 min in 2 dimensional acquisition (2D) and subsequently for 10 min in 3 dimensional acquisition imaging (3D) using a GE $Advance^{TM}$ PET system, The scatter corrected 3D (3D SC) and non scatter-corrected 3D images were compared with 2D images by applying ROIs on gray and white matter, lesion and contralateral normal areas. Measured and calculated attenuation correction methods for emission images were compared to get the maximum advantage of high sensitivity of 3D acquisition. Results: When normalized to the contrast of 2D images, the contrasts of gray to white matter were $0.75{\pm}0.13$ (3D) and $0.95{\pm}0.12$ (3D SC). The contrasts of normal area to lesion were $0.83{\pm}0.05$ (3D) and $0.96{\pm}0.05$ (3D SC). Three nuclear medicine physicians judged 3D SC images to be superior to the 2D with regards to resolution and noise. Regional counts of calculated attenuation correction was not significantly different to that of measured attenuation correction. Conclusion: 3D PET images with the scatter correction in FDG brain studies provide quantitatively and qualitatively similar images to 2D and can be utilized in a routine clinical setting to reduce scanning time and patient motion artifacts.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.33-43
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• 2011

Recently, 3D displays are supplied in the 3D markets so that the demand for 3D stereoscopic contents increases. In general, a simple method is to use a stereoscopic camera. As well, the production of 3D from 2D materials is regarded as an important technology. Such conversion works have gained much interest in the field of 3D converting. However, the stereoscopic image generation from a single 2D image is limited to simple 2D to 3D conversion so that the better realistic perception is difficult to deliver to the users. This paper presents a new stereoscopic content production method where foreground objects undergo alive action events. Further stereoscopic animation is viewed on 3D displays. Given a 2D image, the production is composed of background image generation, foreground object extraction, object/background depth maps and stereoscopic image generation The alive objects are made using the geometric transformation (e.g., translation, rotation, scaling, etc). The proposed method is performed on a Korean traditional painting, Danopungjung as well as Pixar's Up. The animated video showed that through the utilization of simple object transformations, more realistic perception can be delivered to the viewers.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.222-235
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• 2010

After its remarkable success, "Avatar" brought another way of creating cinematic story; the stereoscopic 3-D cinema. Comparing conventional 2-D filmmaking, you need twice as much of budget and manpower in 3-D filmmaking because of the complicated process and slow production speed. The 3-D hardware like 3-D TV and 3-D projector are already showing at the retail stores while 3-D filmmaking is still in veil, and no major educational institution is yet to start 3-D related education. As 3-D movies get popular and demand more 3-D filmmaking professional crew, educating 3-D filmmaking to 2-D based film students will improve their hiring rate in the market. The successful result of the box office showing 3-D films like "Alice in Wonderland 3D" and "Titan 3D" forecasts that there will be more demand on 3-D related jobs very soon.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.92-95
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• 2010

본 논문에서는 2차원 영상을 3차원 영상으로 변환하여 입체감을 주는 방법을 제안하였다. 2D/3D 변환을 위해 Normalized Cut을 사용하여 객체를 분할하였고, 분할된 객체에 Optical Flow 값을 계산해 깊이정보를 생성하여 입체감을 주었다. 객체를 분할하기 위해 Normalized Cut을 이용한 방법에 Optical Flow를 이용한 가중치 값을 추가하여 정확한 객체 분할을 하였고, 처리속도 향상을 위해 영상의 밝기, 색상을 고려한 Watershed 알고리즘을 적용하여 연산량을 줄였다. 분할된 영상에 Optical Flow를 이용하여 색상 정보의 차이를 통해 객체별 고유벡터 값을 연산하여 객체의 움직임 정보를 추출하고 운동시차를 고려해 깊이 정보를 생성하였다. 제안한 방법으로 변환하기 위해 MATLAB을 사용하였다. 제안한 변환 방법은 2D/3D 입체변환에 효과적이었다.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.348-351
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• 2004

In this paper, we propose the face recognition method using Harr wavelet transform and 2D PCA. While previous PCA computed the covariance matrix by using one dimensional vectors, 2D PCA computed the covarinace matrix by using direct two dimensional image and extracted feature vector by solving eigenvalue problem. To gain the face image having the low dimension and robust property, the proposed method uses wavelet transformation. We apply the LL band image data to 2D PCA for face recognition. The experimental results indicate that our method improves recognition rate than 2D PCA into original image.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1687-1693
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• 2015

Recently, demand for digital image processing devices increases rapidly, more clear images have been required. But, in the process of digital image acquisition, processing and transmission, image degradation occurs due to various external reasons and researches about noise reduction are on the rise. Therefore, this study suggested the algorithm to process AWGN(additive white Gaussian noise) by separately processing as three levels according to the pixel distribution in the mask in order to remove AWGN(additive white Gaussian noise) which is added in the image. Regarding the processed results by applying Barbara images which were damaged by AWGN(σ = 15), suggested algorithm showed the improvement by 2.87[dB], 2.95[dB], 2.88[dB], 1.52[dB], 1.49[dB], 1.58[dB] and 1.25[dB] respectively compared with the existing MF(5 × 5), A-TMF(5 × 5), AWMF(5 × 5), MF(3 × 3), A-TMF(3 × 3), AWMF(3 × 3), GF(5 × 5).

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.431-433
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• 2011

본 논문에서는 기존의 영상 및 동영상 편집 툴을 사용하여 2D 동영상을 3D 입체영상으로 변환하는 절차를 분석하고, 변환 과정에서 나타나는 비효율적 요소 및 자동화 가능 요소 등을 분류한다. 또한, 기존의 3D 입체영상 변환 도구의 종류 및 한계점을 분석하고, 분석 내용을 기반으로 3D 입체 영상 변환 전용도구의 필수 기능을 설계한다.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.676-686
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• 2015

A 4D light field image is represented in traditional 2D spatial domain and additional 2D angular domain. The 4D light field has a resolution limitation both in spatial and angular domains since 4D signals are captured by 2D CMOS sensor with limited resolution. In this paper, we propose a dictionary learning-based superresolution algorithm in 4D light field domain to overcome the resolution limitation. The proposed algorithm performs dictionary learning using a large number of extracted 4D light field patches. Then, a high resolution light field image is reconstructed from a low resolution input using the learned dictionary. In this paper, we reconstruct a 4D light field image to have double resolution both in spatial and angular domains. Experimental result shows that the proposed method outperforms the traditional method for the test images captured by a commercial light field camera, i.e. Lytro.

• The Magazine of the IEIE
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• v.31 no.5
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• pp.82-95
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• 2004

3차원 TV 방송 기술(3D Tele-vision), 이 중에서도 스테레오스코픽3DTV기술은 다시점 스테레오스코픽(stereoscopic) 비전 기술을 적용하여 2차원 영상에 깊이 정보를 부가하고, 이 깊이 정보로 인하여 시청자가 마치 영상이 제작되고 있는 현장에 있는 것 같은 생동감 및 현실감을 느낄 수 있게 하는 방송 기술로서 HDTV의 뒤를 이을 차세대 방송기술의 하나로서 기대되고 있다. 현재, 세계적인 규모의 박람회나 전시장 등의 이벤트 행사장에서는 반드시라고 해도 될만큼 3D 디스플레이를 사용한 전시 시설이 설치되어 있으며, 생동감 있는 3D 영상을 즐길 수 있다. 3차원 영상은 눈앞에 펼쳐진 장면을 잡으려고 손을 내밀어 버리거나, 전방에서 다가오는 영상을 엉겁결에 피하거나 할 만큼, 종래의 2D 영상과는 전혀 다른 시각적 효과를 가지고 있다.(중략)