• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.601-604
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• 2003

본 논문은 프로젝션 화면에서 사용자와 컴퓨터간의 상호작용을 위한 인터페이스인 리바이저를 제안한다. 리바이저는 프로젝션 화면에서 사용자의 손 제스처로 문서교정 부호를 인식하여 전자문서를 교정하는 인터페이스 시스템이다. 프로젝션 화면에서 이러한 제스처를 인식하려면 두 가지 문제가 있다. 하나는 다양한 빛의 변화와 복잡한 배경을 가지는 프로젝션 화면에서 전방물체를 검출하는 것이고, 다른 하나는 사용자의 연속적인 움직임에서 사용자의 의도를 알아내는 것이다. 전방물체를 검출하기 위해 프로젝터로 입력되는 영상과 카메라에 의해 캡쳐된 영상 사이의 색상정보를 사용한다. 이 색상정보는 다양한 빛의 변화와 복잡한 배경에서 전방물체를 구별할 수 있게 한다. 연속된 제스처를 인식하기 위해 적출과 인식이 포함된 새로운 제스처 적출방법을 제안한다. 실험결과 제안된 시스템에서 의미없는 움직임이 포함된 제스처 시퀀스에서 사용자 제스처의 인식률은 평균 93.22%로 만족할만한 결과를 보였다.

• Journal of the Korea Computer Graphics Society
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• v.21 no.1
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• pp.1-11
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• 2015

Researchers have developed virtual reality environments to provide audience with more visually immersive experiences than previously possible. One of the most popular solutions to build the immersive VR space is a multi-projection technique. However, utilization of multiple projectors requires large spaces, expensive cost, and accurate geometry calibration among projectors. This paper presents a novel omnidirectional projection system with a single projector and a single spherical mirror.We newly designed the simple and intuitive calibration system to define the shape of environment and the relative position of mirror/projector. For successful image projection, our optimized omnidirectional image generation step solves image distortion produced by the spherical mirror and a calibration problem produced by unknown parameters such as the shape of environment and the relative position between the mirror and the projector. Additionally, the focus correction is performed to improve the quality of the projection. The experiment results show that our method can generate the optimized image given a normal panoramic image for omnidirectional projection in a rectangular space.

• Journal of the Korea Computer Graphics Society
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• v.21 no.3
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• pp.1-10
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• 2015

One way to create a visually immersive environment is to utilize a front projection system. Especially, when enough space is not available behind the screen, it becomes difficult to install a back projection system, making the front projection an appropriate choice. A drawback associated with the front projection is, however, the interference of shadow. The shadow can be cast on the screen when the user is located between the screen and the projector. This shadow can negatively affect the user experience and reduce the sense of immersion by removing important information. There have been various attempts to eliminating shadows cast on the screen by using multiple projectors that compensate for each other with missing information. There is trade-off between calculataion time and desired accuracy in this mutual compensation. Accurate estimation of the shadow usually requires heavy computation while simple approaches suffer from inclusion of non-shadow regions in the result. We propose a novel approach to removing shadows created in the front projection system using the skeleton data obtained from a depth camera. The skeleton data helps accurately extract the shape of the shadow that the user cast without requiring much computation. Our method also utilizes a distance field to remove the afterimage of shadow that may occur when the user moves. We verify the effectiveness of our system by performing various experiments in an interactive environment created by a front projection system.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.79-89
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• 2023

A multi-view display is regarded as the most practical technology to provide a three-dimensional effect to a viewer because it can provide an appropriate viewpoint according to the observer's position. But, most multi-view displays with flat shapes have a disadvantage in that a viewer watches 3D images only within a limited front viewing angle. In this paper, we proposed a spherical display using a ball lens with spherical symmetry that provides perfect parallax by extending the viewing zone to 360 degrees. In the proposed system, each projection lens is designed to be packaged into a small modular array, and the module array is arranged in a spherical shape around a ball lens to provide vertical and horizontal parallax. Through the applied optical module, the image is formed in the center of the ball lens, and 3D contents are clearly imaged with the size of about 0.65 times the diameter of the ball lens when the viewer watches them within the viewing window. Therefore, the feasibility of a 360-degree full parallax display that overcomes the spherical aberration of a ball lens and provides a wide field of view is confirmed experimentally.