• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.109-111
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• 2021

최근 라이트 필드 카메라를 통한 컴퓨터 비전 연구가 활발히 진행되고 있다. 라이트 필드 카메라에서는 공간정보를 가지고 있기 때문에, depth map estimation, super resolution, 3D object detection 과 같은 분야에서 다양한 연구가 진행되고 있다. 본 논문에서는 라이트필드 카메라를 통해 취득되는 7×7 배열의 이미지를 통해 blur 영상에서 객체를 검출하기 위한 방법을 제안한다. 기존의 카메라에서 취약한 blur 영상을 라이트 필드 카메라를 통하여 검출한다. 제안하는 방법은 SSD 알고리즘을 사용하여 실제 라이트 필드 카메라에서 취득한 blur 영상을 사용하여 성능평가를 수행한다

• 천문학회지
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• 제37권4호
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• pp.179-184
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• 2004

We have developed a wide-field imaging camera system, called WICZO, to monitor light of the night sky over extended period. Such monitoring is necessary for studying the morphology of interplanetary dust cloud and also the time and spatial variations of airglow emission. The system consists of an electric cooler a CCD camera with $60\%$ quantum efficiency at 500nm, and a fish-eye lens with $180^{\circ}$ field of view. Wide field imaging is highly desired in light of the night sky observations in general, because the zodiacal light and the airglow emission extend over the entire sky. This paper illustrates the design of WICZO, reports the result of its laboratory performance test, and presents the first night sky image, which was taken, under collaboration with Byulmaro Observatory, on top of Mt. Bongrae at Yongweol in January, 2004.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2015년도 추계학술대회
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• pp.180-181
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• 2015

In this paper, we present a consistent and efficient edit propagation method that is applied for light field data. Unlike conventional sparse edit propagation, the coherency between light field sub-aperture images is fully considered by utilizing light field consistency in the optimization framework. Instead of directly solving the optimization function on all light field sub-aperture images, the proposed optimization framework performs sparse edit propagation in the extended focus image domain. The extended focus image is the representative image that contains implicit depth information and the well-focused region of all sub-aperture images. The edit results in the extended focus image are then propagated back to each light field sub-aperture image. Experimental results on test images captured by a Lytro off-the-shelf light field camera confirm that the proposed method provides robust and consistent results of edited light field sub-aperture images.

• 제어로봇시스템학회논문지
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• 제14권8호
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• pp.767-773
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• 2008

This paper presents a localization system based on the use of electric compass and tracking IR light source. Digital RGB(Red, Green, Blue)signal of digital CMOS Camera is sent to CPLD which converts the color image to binary image at 30 frames per second. CMOS camera has IR filter and UV filter in front of CMOS cell. The filters cut off above 720nm light source. Binary output data of CPLD is sent to DSP that rapidly tracks the IR light source by moving Camera tilt DC motor. At a robot toward north, electric compass signals and IR light source angles which are used for calculating the data of the location system. Because geomagnetic field is linear in local position, this location system is possible. Finally, it is shown that position error is within ${\pm}1.3cm$ in this system.

• 전자통신동향분석
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• 제33권2호
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• pp.56-63
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• 2018

A light field (LF) is a field for expressing the intensity and direction of light reflected from a subject in a 3D space. Dual LF cameras are equipped in smart phones in Korea, mainly those by Samsung and LG. Lytro, Apple, Nvidia, MIT Media Lab, Magic Lip, and NHK are also developing LF camera technologies. LF displays are being researched by ETRI, Samsung Electronics, KIST, KAIST, SNU, MIT Media Lab, USC, HP, Apple, Microsoft, SeeReal, Musion Eyeliner, Dimenco, and Holografika.

• International journal of advanced smart convergence
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• 제10권2호
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• pp.45-52
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• 2021

The surveillance camera market has developed and plays an important role in the field of video surveillance. However, in recent years, the identification of areas requiring surveillance has been limited by reflective light in the surveillance camera market. Cameras using polarization filters are being developed to reduce reflective light and facilitate identification. Programs are required to automatically adjust polarization filters. In this paper, we proposed an optimal angle extraction method from surveillance cameras using polarization filters through histogram analysis. First of all, transformed to grayscale to analyze the specifications of frames in multiple polarized angle images, reducing computational throughput. Then we generated and analyzed a histogram of the corresponding frame to extract the angle when the highlights are the fewest. Experiments with 0˚ and 90˚ showed high performance in extracting optimal angles. At this point, it is hoped this technology would be used for surveillance cameras in place like beach with a lot of reflective light.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2019년도 하계학술대회
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• pp.222-224
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• 2019

Light Field (LF) camera captures not only the light intensity but also the light direction coming to camera. While the rich information captured by LF camera enables many interesting applications such as digital refocusing, viewpoint changing, and 3D reconstruction, but it also requires powerful coding tools to reduce its large volume of data. In this paper, we investigate using the intra prediction scheme of the versatile video coding (VVC), which is the most recent video coding technology currently under developing, to compress the LF image. The Intra Block Copy (IBC) technique in VVC is exploited considering special LF image structure. The experimental result shows that VVC intra predict ion outperforms the H.265/HEVC intra coding technique in encoding LF data irrespective of using the IBC mode or not.

• 방송공학회논문지
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• 제20권5호
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• pp.676-686
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• 2015

Light field 카메라를 이용하여 영상을 취득한 후 다양한 응용 프로그램으로 확장이 가능한 4차원 light field 영상은 일반적인 2차원 공간영역(spatial domain)과 추가적인 2차원 각영역(angular domain)으로 구성된다. 그러나 이러한 4차원 light field 영상을 유한한 해상도를 가진 2차원 CMOS 센서로 취득하므로 저해상도의 제약이 존재한다. 본 논문에서는 이러한 4차원 light field 영상이 가지는 해상도 제약 조건을 해결하기 위하여, 4차원 light field 영상에 적합한 딕셔너리 학습 기반(dictionary learning-based) 초해상도(superresolution) 알고리즘을 제안한다. 제안하는 알고리즘은 4차원 light field 영상으로부터 추출한 많은 수의 4차원 패치(patch)들을 바탕으로 딕셔너리를 구성 및 훈련하며, 학습된 딕셔너리를 바탕으로 저해상도 입력 영상의 해상도를 향상시키는 과정을 수행한다. 제안하는 알고리즘은 공간영역과 각영역의 해상도를 동시에 각각 2배 향상시킨다. 실험에 사용된 영상은 상용 light field 카메라인 Lytro에서 취득하였고 기존의 알고리즘과의 비교를 통해 제안하는 알고리즘의 우수성을 검증한다.

• Journal of Welding and Joining
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• 제21권2호
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• pp.102-110
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• 2003

A visual sensor consisted of polygonal mirror, laser, and CCD camera was proposed to measure the distance to the weld joint for recognizing the joint shape. To scan the laser beam of the sensor onto an object, 8-facet polygonal mirror was used as the rotating mirror. By locating the laser and the camera at axi-symmetrical positions around the mirror, the synchronized-scan condition could be satisfied even when the mirror was set to rotate through one direction continuously, which could remove the inertia effect of the conventional oscillating-mirror methods. The mathematical modelling of the proposed sensor with the optical triangulation method made it possible to derive the relation between the position of an image on the camera and the one of a laser light on the object. Through the geometrical simulation of the proposed sensor with the principal of reflection and virtual image, the optical path of a laser light could be predicted. The position and direction of the CCD camera were determined based on the Scheimpflug's condition to fit the focus of any image reflected from an object within the field of view. The results of modelling and simulation revealed that the proposed visual sensor could be used to recognize the weld joint and its vicinity located within the range of the field of view and the resolution. (Received February 19, 2003)

• 전자통신동향분석
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• 제28권4호
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• pp.97-106
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• 2013

기존 2D 카메라로 획득된 영상은 공간에 존재하는 빛에 대한 손실된 정보를 담고 있어 그 응용에 한계를 가지고 있다. 그러나 공간 내에 존재하는 빛 정보를 획득하여 가지고 있다면 그 공간을 똑같이 인위적으로 다른 장소에서 그대로 재현해 낼 수 있어 다양한 분야에 응용할 수 있을 것으로 기대된다. 근래에 이러한 빛 정보를 획득하기 위한 카메라 기술 및 장치들에 대한 연구개발이 활발히 진행되고 있다. 본고에서는 공간에 존재하는 빛 정보를 나타내기 위한 light field 개념을 소개하고, light field 정보 획득 카메라 기술 및 장치에 대해 살펴본다. 또한 기 개발된 light field 카메라들의 특정들을 비교 분석하고, 다양한 응용 사례에 대해 알아보기로 한다.