• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.139-140
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• 2018

본 논문에서는 열화상 카메라를 사용하는 손가락 인터페이스와 손을 사용하지 않는 인터페이스 연구에서 표면 재질에 따른 잔류 열 생성 차이를 비교하고 분석하고자 한다. 열화상 카메라를 사용하는 인터페이스는 사용자가 프로젝터의 투사 스크린으로 사용되는 표면에 잔류 열을 생성하면 그 잔류 열의 형상을 검출하여 상호작용 할 수 있도록 한다. 스크린으로 사용되는 표면은 활용되는 장소에 따라 표면의 재질이 다를 수 있다. 따라서 일상 환경에서 프로젝터의 투사 스크린으로 사용이 가능한 표면 재질에 따라 다양한 방법으로 잔류 열을 생성하고 잔류 열에 대한 분석이 필요하다. 본 논문에서는 스크린으로 사용될 수 있는 다양한 표면 재질을 선택하여 세 가지 방법으로 잔류 열을 생성하고 열화상 카메라로 촬영한 영상을 분석하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.419-420
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• 2009

현재 공공장소나 학교에서 강의를 할 때 프로젝터를 주로 활용하며, 이때 작은 부분의 그림 등을 상세히 설명하기 위해서는 사용자가 직접 컴퓨터의 마우스를 사용하여 직접 조작해야 하는 불편함이 있다. 본 논문은 이러한 단점을 개선하고자 적외선 센서를 이용하여 화면 이미지의 확대 축소 등을 원격 조작할 수 있는 인터페이스를 설계 구현한다. 구현된 인터페이스는 적외선 LED를 이용하여 모니터의 좌표 점을 인식하고 적외선 센서가 내재되어 있는 Wii컨트롤러를 이용하여 이미지의 이동, 확대 및 축소 등을 실현한다. 구현된 인터페이스 장치는 현재 널리 사용되고 있는 프로젝터들과 연동하여 활용할 수 있다.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.139-140
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• 2008

• Journal of the Korea Computer Graphics Society
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• v.17 no.4
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• pp.31-40
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• 2011

Projector-based visual systems are widely used for VR and experience display applications. But the illumination irregularity on the screen surface due to the screen material and its light reflection properties sometimes deteriorates the user experience. This phenomenon is particularly troublesome when the participants of the head tracking VR system such as CAVE or the motion generation experience system continually move around the system. One of reason to illumination irregularity is projector-screen specular reflection component to participant's eye's position and it's analysis needs high computation complexity. Similar to calculate specular lighting term using GPU's programmable shader, Our research adjusts every pixel's brightness in runtime with given 3D screen space model to reduce illumination irregularity. For doing that, Angle-based brightness compensate function are considered for specific screen installation and modified it for GPU-friendly compute and access. Two aspects are implemented, One is function access transformation from angular form to product and the other is piecewise linear interpolate approximation.

• Journal of Broadcast Engineering
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• v.23 no.5
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• pp.622-627
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• 2018

In this paper, we introduce an integrated augmented reality system using a small camera and a projector. We extract three-dimensional information of an object with a small portable camera and a projector by using a structured light system. We develop the concept of the virtual camera to generalize the projection method so that the image can be projected at a desired position with only the mesh of the object to be projected without computing the mapping between specific point sets. Therefore, it is possible to project not only simple planes but also complex curved surfaces to desired positions without complicated geometric calculation. Based on a robot with a small camera and a projector, it will largely explain the projector-camera system calibration, the calculation of the position of the recognized object, and the image projection method using the virtual camera concept.

• Journal of Korea Game Society
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• v.13 no.3
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• pp.77-84
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• 2013

We introduce a new framework for making spatial augmented reality contents fast and with low cost. The framework allows us to make projection-based augmented reality using off-the-shelf webcams and projectors. Contents producers can make a projection-based augmented reality contents easy and fast by setting a webcam and a projector and then controlling user interfaces of our framework. Since most of previous solutions are expensive and it is too difficult that the producers apply augmented reality techniques themselves, the framework helps them to concentrate contents. Once we set a webcam and a projector correctly, our framework projects a virtual object contents according to the manipulation of a trackable real object. As a result we can see realistic augmented reality contents.

• Journal of the Korea Computer Graphics Society
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• v.13 no.2
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• pp.55-60
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• 2007

Diminished reality (DR) is a technique that provide a visual convenience by virtually hiding an object. Most of existing DR systems have been implemented based on HMDs or desktop displays. However, Here has been no report on the development of DR system based on projection displays due to technical difficulty in spite of its superiority in the aspect of human factor to conventional displays. Rapid advances of projection displays and projection-based vision technologies motivated us to develop a projection-based DR system. As the first attempt, this paper proposes a projection-based diminished reality system using an image completion technique. Its usefulness is demonstrated through experiments and its potential applications are discussed.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.585-594
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• 2011

On live performance such as play and musical, various stage effects are utilized to attract a diverse audience. These stage effects include traditional direction techniques, striking display effects and all kinds of ways of being immersed in the scene. In this paper, we propose a novel digital visual effects(digilog) for controlling the surface texture of objects based on spatial augmented reality. For this purpose, we present a method of neutralizing the appearance of an arbitrary object using a projector-camera system. To make the object appear as if it is a transparent object by projecting a carefully determined compensation image onto the surface of objects, we use the homography method for a simple and effective off-line projector-camera calibration. The successful uses of the basic algorithm of Smart Projector for measuring radiometric parameters led us believe that this method may be used for temporal variation of plays and musicals.

• Journal of Internet Computing and Services
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• v.11 no.5
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• pp.27-35
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• 2010

In this paper, we propose a method that can compensate the geometric distortions of image caused from an arbitrary nonflat display surface(or wall) under the environment of portable overhead projector without a flat screen. In the proposed method, we first project a grid pattern to an arbitrary nonflat display surface and then derive an equation of straight line that represents the geometry relationship between the distorted grid pattern and the original grid pattern. Next, after determining the proper size of the original grid pattern according to the form of the display surface, we generate a compensation pattern from the derived equation of straight line, which can symmetrically compensate for the distorted image. Finally, we compensate for the geometric distortions of the projected image by segmenting the real image to be projected from portable overhead projector and prewarping it according to the compensation pattern. To evaluate the proposed method, we performed experiments of image compensation on inclined surface, bent surface and curved surface that are frequently occurred in the environment of portable overhead projector without a flat screen. From the experimental results, we found that the proposed method could be very effective in compensating for the general types of the geometric distortions of the projected images.

• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.941-950
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• 2008

The quality of projector output image is influenced by the surrounding conditions such as the shape and color of screen, and environmental light. Therefore, techniques that ensure desirable image quality, regardless of such surrounding conditions, have been in demand and are being steadily developed. Among the techniques, radiometric compensation is a representative one. In general, radiometric compensation is achieved by measuring the color of the screen and environmental light based on an analysis of camera image of projector output image and then adjusting the color of projector input image in a pixel-wise manner. This process is not time-consuming for small sizes of images but the speed of the process drops linearly with respect to image size. In large sizes of images, therefore, reducing the time required for performing the process becomes a critical problem. Therefore, this paper proposes a fast radiometric compensation method. The method uses color filters for eliminating the color mixing between projector and camera because the speed of radiometric compensation depends mainly on measuring color mixing between projector and camera. By using color filters, there is no need to measure the color mixing. Through experiments, the proposed method improved the compensation speed by 44 percent while maintaining the projector output image quality. This method is expected to be a key technique for widespread use of projectors for large-scale and high-quality display.