• Journal of information and communication convergence engineering
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• 제9권1호
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• pp.83-88
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• 2011

Abstract. Image segmentation is always a challenging task in computer vision as well as in pattern recognition. Nowadays, this method has great importance in the field of stereo vision. The disparity information extracting from the binocular image pairs has essential relevance in the fields like Stereoscopic (3D) Imaging Systems, Virtual Reality and 3D Graphics. The term 'disparity' represents the horizontal shift between left camera image and right camera image. Till now, many methods are proposed to visualize or estimate the disparity. In this paper, we present a new technique to visualize the horizontal disparity between two stereo images based on image segmentation method. The process of comparing left camera image with right camera image is popularly known as 'Stereo-Matching'. This method is used in the field of stereo vision for many years and it has large contribution in generating depth and disparity maps. Correlation based stereo-matching are used most of the times to visualize the disparity. Although, for few stereo image pairs it is easy to estimate the horizontal disparity but in case of some other stereo images it becomes quite difficult to distinguish the disparity. Therefore, in order to visualize the horizontal disparity between any stereo image pairs in more robust way, a novel stereo-matching algorithm is proposed which is named as "Quadtree Segmentation of Pixels Disparity Estimation (QSPDE)".

• 정보처리학회논문지A
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• 제10A권2호
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• pp.165-172
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• 2003

본 논문에서는 프로젝션 테이블(the projection table)과 프로젝션 월(the projection wall)을 이용하여 수평 및 수직형 가상 공간을 구축하고, 이러한 가상 환경에서 삼차원 건물을 사용자의 시점에 따라 입체적으로 가시화하는 시스템을 구현하였다. 수평형 디스플레이 장비인 프로젝션 테이블은 위에서 내려다 보는 형태의 뷰잉 프러스텀(viewing frustum)을 갖기 때문에 책상이나 테이블에서의 작업을 재현하거나 bird-eye view가 필요한 응용분야에서 효과적으로 사용되어진다. 반면에 수직형 디스플레이 장비인 대형 프로젝션 월은 정면에서 바라보는 형태의 뷰잉 프러스텀을 갖기 때문에 가상 공간을 네비게이션 할 때 보다 효과적으로 사용되어진다. 본 논문에서는 주요 객체는 세밀한 삼차원 모델로 생성하고 배경은 영상을 이용함으로써 사용자와 가상 객체간의 빠른 상호작용을 제공하도록 하였으며, 모델과 영상이 합성된 결과를 상이한 가상환경에서 사용자의 위치 및 시점과 연동하여 입체적으로 보여줌으로써 사용자의 현실감을 증진시키도록 하였다.

• 한국컴퓨터정보학회논문지
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• 제17권6호
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• pp.29-36
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• 2012

본 논문에서는 입력되는 3차원의 정지 또는 동적인 입체영상으로부터 색상과 깊이 특징을 결합하여 인간의 피부색상 영역을 강건하게 추출하는 새로운 방법을 제안한다. 제안된 방법에서는 먼저 스테레오 정합 기법을 이용하여 입력된 좌우 영상으로부터 카메라와 물체 사이의 거리를 나타내는 깊이 특징을 강건하게 추출한다. 그런 다음, 유사한 깊이 특징을 가지는 화소들을 레이블링하고, 레이블링한 영역 중에서 인간의 피부색상 분포를 가지는 영역들을 실제적인 피부색상 영역이라고 판단한다. 실험에서는 2차원 위주의 기존의 피부영역 추출 방법과 제안된 3차원의 특징을 활용한 방법의 성능을 정확도 측면에서 비교 및 평가하였다. 그 결과 제안된 방법은 색상 특징과 깊이 특징을 효과적으로 결합함으로써 기존의 배경 영역에서 부정확하게 검출되는 피부색상 영역의 오류를 상당수 제거하는 효과를 가지며, 이로 인해 전반적으로 보다 정확하게 피부영역을 추출하였다.

• 대한전자공학회논문지SP
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• 제48권6호
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• pp.61-67
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• 2011

3D TV를 위한 스테레오 영상은 기존의 디지털 TV와 호환성을 유지하기 위하여 프레임 호환 패킹 포맷으로 전송될 수 있다. 이 경우 수신단은 해상도가 절반으로 줄어든 스테레오 영상으로부터 원래 크기의 좌우 영상을 확대하여 복원할 필요가 있다. 이 논문은 삭제된 영상 라인의 픽셀값을 적응적으로 내삽하는 기법을 제안한다. 삭제되지 않은 주변 영상 라인의 정보로부터 수평라인 기반 선형 필터와 NEDI6를 선택적으로 적용함으로써 기존의 Bilinear 내삽 기법에 비해 0.6dB 정도의 화질 향상을 달성할 수 있었다.

• ETRI Journal
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• 제31권1호
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• pp.1-9
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• 2009

Frequency domain analysis is a fundamental procedure for understanding the characteristics of visual data. Several studies have been conducted with 2D videos, but analysis of stereoscopic 3D videos is rarely carried out. In this paper, we derive the Fourier transform of a simplified 3D video signal and analyze how a 3D video is influenced by disparity and motion in terms of temporal aliasing. It is already known that object motion affects temporal frequency characteristics of a time-varying image sequence. In our analysis, we show that a 3D video is influenced not only by motion but also by disparity. Based on this conclusion, we present a temporal anti-aliasing filter for a 3D video. Since the human process of depth perception mainly determines the quality of a reproduced 3D image, 2D image processing techniques are not directly applicable to 3D images. The analysis presented in this paper will be useful for reducing undesirable visual artifacts in 3D video as well as for assisting the development of relevant technologies.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.1-13
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• 2004

A scanning stereo-PIV system was developed to measure the three-dimensional distribution of three-component velocity in a turbulent round jet. A laser light beam produced by a high repetition rate YLF pulse laser was expanded vertically by a cylindrical lens to form a laser light sheet. The light sheet is scanned in a direction normal to the sheet by a flat mirror mounted on an optical scanner, which is controlled by a programmable scanner controller. Two high-speed mega-pixel resolution C-MOS cameras captured the particle images illuminated by the light sheet, and stereoscopic PIV method was adopted to acquire the 3D-3C-velocity distribution of turbulent round jet in an octagonal tank filled with water. The jet Reynolds number was set at Re=1000 and the streamwise location of the measurement was fixed at approximately x = 40D. Time evolution of three-dimensional vortical structure, which is identified by vorticity, is visualized. It revealed that the existence of a group of hairpin-like vortex structures was quite evident around the rim of the shear layer of the jet. Turbulence statistics shows good agreement with the previous data, and divergence of a filtered (unfiltered) velocity vector field was $7\%\;(22\%)$ of root-me an-squared vorticity value.

• 방송공학회논문지
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• 제13권5호
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• pp.596-601
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• 2008

본 논문은 저해상도의 깊이 카메라와 고해상도의 양안식 카메라를 결합한 복합형 카메라 시스템에서 관심영역(region of interest, ROI)이 향상된 깊이맵을 생성하는 새로운 방법을 제안한다. 제안하는 방법은 깊이 카메라로 획득한 깊이 정보를 3차원 워핑(warping)하여 좌영상의 ROI 깊이맵을 생성한다. 그런 다음, 양안식 카메라로 획득한 좌우영상의 배경 영역을 스테레오 정합하여 좌영상의 배경 깊이맵을 생성한다. 최종적으로, ROI 깊이맵과 배경 깊이맵을 결합하여 최종 깊이맵을 생성한다. 제안하는 방법으로 생성한 고해상도 깊이맵은 기존의 스테레오 정합 방법보다 ROI에 정확한 깊이 정보를 제공한다.

• Journal of Advanced Marine Engineering and Technology
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• 제37권7호
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• pp.729-736
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• 2013

The turbulent properties in a mixed statistically stationary flow were investigated experimentally by a pseudo stereoscopic PIV. In order to validate the experimental results, the profiles of the turbulent kinetic energy were evaluated with the flow features. A mechanical agitator having 6 blades was installed at the bottom of the mixing tank (D=60cm, H=60cm). The agitator was rotated with 80rpm clockwise and counter-clockwise. For the measurements, three cameras were used and all were synchronized. The images captured by one of the three cameras was used for the measurement of rotational speed, and the images captured by the other two cameras were used to measure three dimensional components of velocity vectors. All vectors captured at the same rotational angle were phase averaged to construct three-dimensional vector fields to reconstruct the spatial distribution of the flow properties. It was seen that the jet scrolling along the tank was the main source of mixing.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1311-1313
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• 2006

Stereoscopic/autostereoscopic systems have been developed in order to express true 3D images, but have never had great success in the practical use. In order to apply 3D display to promising applications such as advertisements and games, we've developed a 42" 2D/3D switchable display. It has characteristics that don't require special glasses for 3D images, use multi-view technology for improving 3D viewing characteristics, and has a 2D/3D switching function to express dynamic 3D contents as well as conventional 2D contents.

• Journal of information and communication convergence engineering
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• 제13권1호
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• pp.62-68
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• 2015

In this paper, we propose a watermarking method for protecting the ownership of three-dimensional (3D) content generated from depth and texture images. After selecting the target areas to preserve the watermark by depth-image-based rendering, the reference viewpoint image is moved right and left in the depth map until the maximum viewpoint change is obtained and the overlapped region is generated for marking space. The region is divided into four subparts and scanned. After applying discrete cosine transform, the watermarks are inserted. To extract the watermark, the viewpoint can be changed by referring to the viewpoint image and the corresponding depth image initially, before returning to the original viewpoint. The watermark embedding and extracting algorithm are based on quantization. The watermarked image is attacked by the methods of JPEG compression, blurring, sharpening, and salt-pepper noise.