• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2013년도 추계학술대회
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• pp.124-127
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• 2013

2009년 출시된 영화 "AVATAR"가 stereoscopic방식 3D영화로 대단한 성공을 거둔 이후로 가전시장과 필름 시장에는 많은 3D 영상들이 stereoscopic방식으로 제작되어 유통되게 되었다. 하지만 기존에 제시되어온 two lens stereoscopic camera system은 두 대의 카메라를 사용하기 때문에 광학적 정렬과 기하학적 조절이 매우 어렵기 때문에 stereoscopic 영상을 촬영하고 보급 하는데 많은 문제점을 가지고 있었다. 따라서 하나의 광축을 가진 single lens stereoscopic camera system들이 기존에 제시되어 왔으나 여전히 single lens stereoscopic system에도 문제점이 존재한다. 이에 본 논문에서는 기존에 제시된 stereoscopic camera system을 two lens / single lens로 나누어 조사 분석하고, 분석한 문제점을 해결하기 위한 새로운 single lens stereoscopic camera system을 제안할 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5481-5495
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• 2018

Single pixel imaging technology has developed for years, however the video acquisition on the single pixel camera is not a well-studied problem in computer vision. This work proposes a new scheme for single pixel camera to acquire video data and a new regularization for robust signal recovery algorithm. The method establishes a single pixel video compressive sensing scheme to reconstruct the video clips in spatial domain by recovering the difference of the consecutive frames. Different from traditional data acquisition method works in transform domain, the proposed scheme reconstructs the video frames directly in spatial domain. At the same time, a new regularization called spatial cluster is introduced to improve the performance of signal reconstruction. The regularization derives from the observation that the nonzero coefficients often tend to be clustered in the difference of the consecutive video frames. We implement an experiment platform to illustrate the effectiveness of the proposed algorithm. Numerous experiments show the well performance of video acquisition and frame reconstruction on single pixel camera.

• 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.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.955-959
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• 2013

It is possible to obtain an omnidirectional stereo image via a single camera by using a catadioptric approach with a convex mirror and concave lens. In order to measure three-dimensional distance using the imaging system, the optical parameters of the system are required. In this paper, a calibration procedure to extract the parameters of the imaging system is described. Based on the parameters, experiments are carried out to verify the performance of the three-dimensional distance measurement of a single camera omnidirectional stereo imaging system.

• 방송공학회논문지
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• 제24권2호
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• pp.281-291
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• 2019

3D 카메라 기술 중에서 초점의 흐려짐을 이용한 깊이 추정은 카메라의 초점거리 평면의 물체는 선명한 상이 맺히지만 카메라의 초점거리 평면으로부터 멀어진 물체는 흐린 영상을 만들어낸다는 현상을 이용해 3D 깊이를 추정한다. 본 논문에서는 단일 카메라를 이용하여 촬영한 영상의 흐림 정도를 분석하여 3D 깊이를 추정하는 알고리즘을 연구하였다. 단일 카메라의 1 개의 영상 또는 단일 카메라의 초점이 서로 다른 2 개의 영상을 사용하여 초점의 흐려짐을 이용한 3D 깊이를 추정하는 방법을 통해 최적화된 피사체 범위를 도출하였다. 1 개의 영상을 이용한 깊이 추정에서는 스마트폰 카메라와 DSLR 카메라 모두 250 mm의 초점거리를 사용하는 것이 가장 좋은 성능을 보였다. 2개의 영상을 이용한 깊이 추정에서는 스마트폰 카메라 영상은 150 mm와 250 mm로 그리고 DSLR 카메라 영상은 200 mm와 300 mm로 초점거리를 설정하였을 때 가장 좋은 3D 깊이 추정 유효 범위를 갖는 것으로 나타났다.

• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.686-692
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• 2006

This paper shows the calculation of 3D geometric information such as height, direction and distance under the constraints of a catadioptric camera system. The catadioptric camera system satisfies the single viewpoint constraints adopting hyperboloidal mirror. To calculate the 3D information with a single omni-directional image, the points are assumed to lie in perpendicular to the ground. The infinite plane is also detected as a circle from the structure of the mirror and camera. The analytic experiments verify the correctness of theory using real images taken in indoor environments like rooms or corridors. Thus, the experimental results show the applicability to calculate the 3D geometric information using single omni-directional images.

• 대한기계학회논문집B
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• 제24권1호
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• pp.21-28
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• 2000

Although commercial PIV systems have been widely used for the non-intrusive velocity field measurement of fluid flows, they are still under development and have considerable room for improvement. In this study, a single-frame double-exposure PIV system using a high-resolution CCD camera was developed. A pulsed Nd:Yag laser and high-resolution CCD camera were synchronized by a home-made control circuit. In order to resolve the directional ambiguity problem encountered in the single-frame PIV technique, the second particle image was genuinely shifted in the CCD sensor array during the time interval dt. The velocity vector field was determined by calculating the displacement vector at each interrogation window using cross-correlation with 50% overlapping. In order to check the effect of spatial resolution of CCD camera on the accuracy of PIV velocity field measurement, the developed PIV system with three different resolution modes of the CCD camera (512 ${\times}$ 512, lK ${\times}$ IK, 2K ${\times}$ 2K) was applied to a turbulent flow which simulate the Zn plating process of a steel strip. The experimental model consists of a snout and a moving belt. Aluminum flakes about $1{\mu}m$ diameter were used as scattering particles for the liquid flow in the zinc pot and the gas flow above the zinc surface was seeded with atomized olive oil with an average diameter of 1-$3{\mu}m$. Velocity field measurements were carried out at the strip speed $V_s$=1.0 m/s. The 2K ${\times}$ 2K high-resolution PIV technique was significantly superior compared to the smaller pixel resolution PIV system. For the cases of 512 ${\times}$ 512 and 1K ${\times}$ 1K pixel resolution PIV system, it was difficult to get accurate flow structure of viscous flow near the wall and small vortex structure in the region of large velocity gradient.

• Journal of information and communication convergence engineering
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• 제18권2호
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• pp.75-81
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• 2020

Approximately 1.3 million people die from traffic accidents each year, and smartphone usage while driving is one of the main causes of such accidents. Therefore, detection of smartphone usage by drivers has become an important part of distracted driving detection. Previous studies have used single camera-based methods to collect the driver images. However, smartphone usage detection by employing a single camera can be unsuccessful if the driver occludes the phone. In this paper, we present a driver smartphone usage detection system that uses multiple cameras to collect driver images from different perspectives, and then processes these images with ensemble convolutional neural networks. The ensemble method comprises three individual convolutional neural networks with a simple voting system. Each network provides a distinct image perspective and the voting mechanism selects the final classification. Experimental results verified that the proposed method avoided the limitations observed in single camera-based methods, and achieved 98.96% accuracy on our dataset.

• 제어로봇시스템학회논문지
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• 제6권5호
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• pp.383-389
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• 2000

This paper presents a stereo camera system that provides a Pair of stereo images using a Biprism. The equivalent of a stereo Pair of images is formed as the left and right halves of a single CCD image. The system is therefore cheap and extremely easy to calibrate since it requires only one CCD camera. An additional advantage of the geometrical set-up is that corresponding features lie on the same scanline automatically, The single camera and Biprism have led to a simple stereo system for which correspondence is very easy and which is accurate for nearby objects in a small field of view. Since we use only a single lens, calibration of the system is greatly simplified. Given the parameters in the Biprism-stereo camera system, we can reconstruct the 3-D structure using only the disparity between the corresponding points.

• 한국측량학회지
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• 제36권4호
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• pp.295-303
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• 2018

스테레오 카메라 시스템은 물리적으로 고정된 기선길이를 가지고 있어 축척이 일정하나 스테레오 영상에서 매번 특징점 매칭을 통해서 상호표정요소를 결정할 경우 축척이 고정 되어 있지 않아 실제 3차원 좌표를 측정하기 어려운 문제점이 있다. 따라서 본 연구에서는 수정된 공선조건식을 이용하여 좌우측 카메라의 내부적인 특성 및 카메라간의 관계를 동시에 결정하는 스테레오 카메라 캘리브레이션을 수행하고 이를 단일 카메라 캘리브레이션과 비교하는 것을 목적으로 하였다. 실험을 통해 근거리에 촬영한 영상에서 결정한 3차원 거리를 비교하였을 경우 단일 캘리브레이션의 결과에서는 ${\pm}0.014m$의 평균제곱근오차가 발생한 반면 스테레오 카메라의 경우에는 오차가 거의 발생하지 않았기 때문에 스테레오 카메라 캘리브레이션의 3차원 거리의 정확도가 우수하게 나타났다. 에피폴라 영상의 종시차에 대한 비교에서는 스테레오 카메라를 이용한 경우가 단일 카메라의 경우 보다 평균제곱근오차가 최대 0.3 픽셀 정도의 차이를 보였으나 그 영향은 크지 않은 것으로 나타났다.