• 한국통신학회논문지
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• 제31권3A호
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• pp.337-344
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• 2006

본 논문에서는 3DTV를 위한 다시점 동영상 부호화 기법을 제안한다. 제안하는 기법에서는 다수의 카메라 입력에 대하여 기존의 MPEG 기반의 부호화 기법에서 사용된 시 공간적 중복성 제거 뿐 아니라 각 시점에 해당하는 영상간의 공간적 중복성을 제거하여 부호화 효율을 재선할 수 있다. 각 시점 영상간의 공간적 중복성을 효율적으로 제거하기 위하여 전역 시차 보상(global disparity compensation)된 집적영상(assembled image)을 사용하였다. 또한 기존의 디지털 TV 전송 표준인 MPEG-2를 기반으로 하였기 때문에 기존의 디지털 TV 표준을 크게 수정하지 않고 3DTV를 구현할 수 있을 뿐만 아니라 각 시점간의 동기화 문제도 해결할 수 있다. 제안하는 기법은 MPEG-2 기법으로 각 시점에 해당하는 영상을 독립적으로 부호화(simulcast 기법)한 결과와 비교하여 객관적 화질 면에서 우수한 결과를 보였으며, 평행식 카메라 구조로 획득된 영상과 유사한 디지털 홀로그램 부호화에도 적용하여 우수한 성능을 얻을 수 있었다.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권11호
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• pp.626-633
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• 2003

Theoretical analysis of the depth measurement system with the use of a single camera and a rotating mirror has been done. A camera in front of a rotating mirror acquires a sequence of reflected images, from which depth information is extracted. For an object point at a longer distance, the corresponding pixel in the sequence of images moves at a higher speed. Depth measurement based on such pixel movement is investigated. Since the mirror rotates along an axis that is in parallel with the vertical axis of the image plane, the image of an object will only move horizontally. This eases the task of finding corresponding image points. In this paper, the principle of the depth measurement-based on the relation of the pixel movement speed and the depth of objects have been investigated. Also, necessary mathematics to implement the technique is derived and presented. The factors affecting the measurement precision have been studied. Analysis shows that the measurement error increases with the increase of depth. The rotational angle of the mirror between two image-takings also affects the measurement precision. Experimental results using the real camera-mirror setup are reported.

• 방송공학회논문지
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• 제23권6호
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• pp.896-913
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• 2018

360 VR 영상을 구성하는 과정에서 합성되는 영상들 사이의 경계(seam)를 정확하고 효율적으로 추출하는 것은 스티칭된 영상의 화질에 매우 중요한 영향을 끼친다. 기존의 seam finding 기술들인 보로노이(Voronoi) 알고리즘, dynamic programming, graph cut 방법들은 시차(view disparity)가 존재하거나 이동하는 물체가 존재하는 상황에서는 ghost와 같은 왜곡을 발생시킨다. 본 논문에서는 기존 알고리즘들과 달리 물체를 가로지르지 않고, 물체를 피해 배경을 가로질러 접합선을 추출하는 '밝기 대비를 이용한 마스크 추출 방법'을 제안하였다. 이때, 배경과 물체와의 밝기차이를 이용하여, 물체의 형상을 따라 이어지는 접합선을 추출했다. 본 논문의 실험 결과를 통해, 제안하는 기술을 사용하면 왜곡을 감소시키는 위치에서 접합선이 생성되고, 스티칭된 영상의 화질이 개선되는 것을 확인하였다.

• 전자공학회논문지S
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• 제35S권2호
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• pp.126-136
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• 1998

One of the central problems in sereo matching is the selectionof the optimal window sizes for comparing image regions. The window size must be large enough to include enough variation for reliable matching, but small enough to avoid the effect of projection distortion. This paper discusses these problems with some novel algorithm based on iterativediffusion process at different disparity hypotheses. Also this paper proposes four kinds of diffusion algorithms to preseve discontinuity in stereo matching. We present and discuss extensive empirical results of algorithms based on various sets of synthetic and real image.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.32-38
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• 2007

In this study, a new algorithm for measuring the velocity and distance from a camera to a moving object by using pseudo-stereo images obtained from a single camera with a stereo adapter is proposed. The proposed system is similar to a parallel visual stereo system using a two-camera system, but because this system can obtain pseudo-stereo images form a single camera, it has advantages not only in the aspect of cost but also in stereo conformity by arrangement and the calibration of the left and right stereo cameras upon image processing.

• 센서학회지
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• 제7권6호
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• pp.394-400
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• 1998

In this paper, we present a robust and fast method that enables real-time computing of axial motion component of different points of a scene from a stereo images sequence. The aim of our method is to establish axial motion maps by computing a range of disparity maps. We propose a solution in two steps. In the first step we estimate motion with a low level computing for an image point by a detection estimation-structure. In the second step, we use the neighbourhood information of the image point with morphology operation. The motion maps are established with a constant computation time without spatio-temporal matching.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.859-863
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• 1993

There are two methods to get 3-dimensional information by matching image pair feature-based matching and area-based matching. One of the problems in the area-based matching is how the optimal search region which gives accurate correlation between given point and its neighbors can be selected. In this paper, we proposed a new area-based matching algorithm which uses edge-features used in the conventional feature-based matching. It first selects matching candidates by feature-based and matches image pair with area-based method by taking these candidates as guidance to decision of search area. The results show that running time is reduced by optimizing search area(considering edge points and continuity of disparity), keeping on the precision as the conventional area-based matching method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.237-240
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• 2003

We implement a system for 3D structure reconstruction from multiple 2D images. It uses geometric primitives such as box, wedge, pyramid, etc, each having translation, rotation, and scale parameters. Primitives are marked on input images with GUI (Graphic User Interface). Lines made by projection of primitives onto an image correspond to marked line segments of the image. Error function is defined by disparity between them and is minimized by downhill simplex method. By assigning relationship between models, the number of parameters to solve can be decreased and the resultant models become more accurate To share variables among other models also reduces computational complexity. Experiments using real images have shown that the proposed method successfully reconstructs 3D structure.

• 전자공학회논문지S
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• 제34S권9호
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• pp.109-117
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• 1997

A new relaxation algorithm based on distribution of matched errors and possibility is proposed to solve efficiently correspondence problem. This algorithm can be applied to various method, such as BMA, feature-, and region-based matching methods, by modifying its smoothness function. It consists of two stages which are transformation and iteration process. In transformation stage, the errors obtained by any matching algorithm are transformed to possibility values according to these statistical distribution. Each grade of possility is updated by some constraints which are defined as smoothness, uniqueness, and discontinuity factor in iteration stage. The discontinuity factor is used to reserve discontinuity of disparity. In conventional methods, it is difficult to find proper weights and stop condition, because only two factors, smoothness and uniqueness, have been used. However, in the proposed mthod, the more smoothing is not ocurred because of discontinuity factor. And it is efective to the various image, even if the image has a severe noise and repeating patterns. In addition, it is shown that the convergence rate and the quality of output are improved.

• 한국멀티미디어학회논문지
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• 제9권10호
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• pp.1296-1303
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• 2006

거리 기반법은 상세한 3D 데이터를 얻기 쉬운 반면 영상 기반법은 그렇지 않다. 본 논문에서는 확대 양안입체 영상으로부터 상세한 3차원 데이터를 얻는 새로운 방법을 제시한다. 주 아이디어는 확대경을 사용하는 것이다. 확대경은 물체를 확대할 뿐만 아니라 깊이 해상도도 증가시킨다. 깊이 해상도 증가와 변위 증폭 사이의 관계를 수학적으로 증명하고 원 3D 데이터를 개선시키는 방법이 제시된다.