• 천문학회지
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• 제50권1호
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• pp.1-5
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• 2017

Like Hipparcos, Gaia is designed to give absolute parallaxes, independent of any astrophysical reference system. And indeed, Gaia's internal zero-point error for parallaxes is likely to be smaller than any individual parallax error. Nevertheless, due in part to mechanical issues of unknown origin, there are many astrophysical questions for which the parallax zero-point error ${\sigma}({\pi}_0)$ will be the fundamentally limiting constraint. These include the distance to the Large Magellanic Cloud and the Galactic Center. We show that by using the photometric parallax estimates for RR Lyrae stars (RRL) within 8kpc, via the ultra-precise infrared period-luminosity relation, one can independently determine a hyper-precise value for ${\pi}_0$. Despite their paucity relative to bright quasars, we show that RRL are competitive due to their order-of-magnitude improved parallax precision for each individual object relative to bright quasars. We show that this method is mathematically robust and well-approximated by analytic formulae over a wide range of relevant distances.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.644-648
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• 2009

Accurate rendering of a virtual scene in real time has been one of important issues for virtual reality (VR) technology. Specular reflection of light has been studied a long time, which is always seen on a metallic object and causes occasionally very strong brightness (highlight). Due to restriction of number of gradation of brightness (usually 256), maximum brightness and contrast ratio, the highlight is relatively weakly represented by displays and projectors. In addition, specular reflection will be take influence of binocular parallax and motion parallax, because it is light to reflect in a specific course. Therefore in this paper, an emphasized highlight model of a metallic object on the CAVE system is proposed. Decreasing brightness slightly on neighbor area of highlighted area, the proposed method increases contrast ratio between the highlighted area and neighbor area. Furthermore, using features of CAVE, the proposed method also represents glance (blink). When a metallic object moves, the method alternatively represents images with highlight and without highlight for both eyes. Since the difference of images for both eyes influences binocular parallax and motion parallax, a userfeels glance more realistically.

• 한국광학회지
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• 제31권1호
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• pp.26-30
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• 2020

로봇 카메라를 이해하고 제작하기 위해서는 로봇 카메라의 회전이나 공간 이동에 의해 발생하는 인접 이미지 간의 영상 왜곡에 대한 이해가 우선적으로 진행되어야 한다. 본 논문에서는 영상 왜곡에 관한 수학적인 해석과 이 수학적인 해석을 렌즈 시스템과 연결하여 일반화하고 결국 로봇 카메라에서 일어나는 영상의 왜곡인 parallax 오차에 대한 유용한 해석 방정식을 얻었다. 이 방정식으로부터 로봇 카메라의 구조설계가 가능하게 되고 한 예로서 기존 구글의 ART 로봇 카메라에 대한 분석과 이해가 확장될 수 있었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.452-455
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• 2007

3D stereoscopic viewing of large scale imagery, such as aerial photography and satellite images, needs different parallaxes relative to the display scale. For example, when a viewer sees a stereoscopic image of aerial photography, the optimal parallax of its zoom-in image should be smaller than that of its zoom-out. Therefore, relative parallax adjustment according to the display scale is required. Merely adjusting the spacing between stereo images is not appropriate because the depths of the whole image are either exaggerated or reduced entirely. This paper focuses on the improving stereoscopic viewing with a single remote sensing image and a digital surface model (DSM). We present the parallax adjustment technique to maximize the 3D realistic effect and the visual comfort. For remote sensing data, DSM height value can be regarded as disparity. There are two possible kinds of methods to adjust the relative parallax with a single image performance. One is the DSM compression technique: the other is an adjustment of the distance between the original image and its stereo-mate. In our approach, we carried out a test to evaluate the optimal distance between a single remote sensing image and its stereo-mate, relative to the viewing scale. Several synthetic stereo-mates according to certain viewing scale were created using a parallel projection model and their anaglyphs were estimated visually. The occlusion of the synthetic stereo-mate was restored by the inpainting method using the fields of experts (FoE) model. With the experiments using QuickBird imagery, we could obtain stereoscopic images with optimized parallax at varied display scales.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1729-1732
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• 2007

We introduce a mobile-type 3D display that achieves a full directional motion parallax and the real time interactions between the observer and the 3D image at the same time. These effects can be unique specified to the mobile-type 3D display.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1129-1132
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• 2005

In this paper, we proposed real-time stereoscopic image conversion algorithm using object segmentation and motion parallax. The proposed algorithm separates objects using luminance of image, extracts moving object among objects of the image using motion parallax and generates depth map. Parallax process is done based on the depth map. The proposed method has been evaluated using visual test and APD(Absolute Parallx Difference) for comparing the stereoscopic image of the proposed method with that of MTD. The proposed method offers realistic stereoscopic conversion effect regardless of the direction and velocity of the 2-D image.

• 제어로봇시스템학회논문지
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• 제18권1호
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• pp.7-12
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• 2012

In this paper, we present an effective viewpoint estimation algorithm for the Moving parallax barrier method of 3D display mobile device. Moving parallax barrier is designed to overcome the biggest problem, the limited view angle. To accomplish it, the position of the viewer's eyes or face should be estimated with strong stability and no latency. We focus on these requirements in the poor performance of mobile processors. We used a pre-processing algorithm in order to overcome the various illumination changes. And, we combined the conventional Viola-Jones face detection method and Optical-flow algorithm for robust and stable viewpoint estimation. Various computer simulations prove the effectiveness of the proposed method.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.189-192
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• 2009

We present a novel head tracking system for stereoscopic displays that ensures the viewer has a high degree of movement. The tracker is capable of segmenting the viewer from background objects using their relative distance. A depth camera is used to generate a key signal for head tracking application. A method of the moving parallax barrier is also introduced to supplement a disadvantage of the fixed parallax barrier that provides observation at the specific locations.

• 한국게임학회 논문지
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• 제8권1호
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• pp.71-77
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• 2008

높이 맵으로부터 지형의 기하구조를 형성하고 그 세부 묘사를 위하여 왕 타일을 이용하여 반복적이지 않는 타일링을 할 수 있다. 타일 내에 색상 정보와 더불어 높이 정보를 추가하여 세부적인 요철의 정보를 담아 시차 맵핑을 통하여 효과적으로 표현 할 수 있다. 본 논문에서는 이를 실시간 렌더링 할 때 문제되는 부분을 해결하였으며, 지형을 위한 시차 맵핑의 보안을 제안한다.

• Journal of Information Display
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• 제12권1호
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• pp.43-46
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• 2011

A three-dimensional windshield display (3D-WSD) can present driving information at the same depth as the objects in the outside scene. Herein, a super-multiview 3D-WSD is proposed because the super-multiview display technique provides smooth motion parallax. Motion parallax is the only physiological cue for perceiving the depth of a 3D image displayed at a far distance, which cannot be perceived by vergence and binocular parallax. A prototype system with 36 views was constructed, and the discontinuity of motion parallax and accuracy of depth perception were evaluated.