• Journal of the Korea Computer Graphics Society
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• v.20 no.1
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• pp.13-19
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• 2014

In this paper, we introduce a real-time method to render a 3D scene using image-based lighting. Previous approaches for image-based lighting focused on diffuse reflection and mirror-like specular reflection. In this paper, we provide a simple preprocessing approach to efficiently approximate Phong reflection model, which has been used for computer graphics applications for several decades. For diffuse reflection, we generate a texture map for diffuse reflection by integrating the source image in preprocessing step, similarly to the previous approaches. We adopt the similar idea to produce a set of specular reflection maps for various material shininess. By doing this, we can render a dynamic scene without high computational complexity or numerous texture map access.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.154-159
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• 2019

Undesirable negative image is occurred in photographs taken across partial reflections such as glass window and electronic display. Efficient removing reflections given a single image are in the spotlight in recent researches. This paper discusses and evaluates two published image reflection removal algorithms, and compares the performance of time and quality of those methods with a common dataset. As benchmarking test cases are presented, we propose to modify one of the methods to reduce the run-time with small effects on the similar image quality.

• Journal of the Semiconductor & Display Technology
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• v.20 no.1
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• pp.108-112
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• 2021

Undesired reflection removal from an image captured through glass window is widely needed with the prevalence of camera. In this paper, we present and implement a reflection removal algorithm, which is specially designed for smart devices. Our implementation requires smart phone application to take two input pictures of the same target, one with flash light on and another with flash light off. Then, we find a flash spot in the picture, match the features to align the input pictures, transform the color space, and finally combine the pictures. As the result, we get a resulting image with removed reflection, achieving the visually pleasant.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.29-34
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• 2004

The aim of this thesis research is to develop equipment measuring refractive state in order to measure the general ocular function using PC-based Foucault Test(Knife Edge Test). The Image of light generated from the reflection of incident light in retina thru Knife Edge Test was photographed using a CCD camera. The resulting image was then analyzed to measure the size of pupil by measuring the diameter of reflected image. The reflection state was judged from the orientation of reflected image and the degree of abnormal reflection was confirmed by measuring the size of second image of reflection. The aberration value was calculated from the magnitude of spherical aberration obtained by comparing the brightness of second reflected image appeared in the opposite direction to the reflected image.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.201-207
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• 1998

It was theoretically calculated the image position and size using matrix to obtain the reflection pattern for eye's cornea and crystalline, and made system to measure the reflection pattern by three light sources and a reflex camera. Hyperopia and myopia were measured by reflect pattern using single light source at retina, and cornea and curvature of crystalline were measured by the reflection pattern using double light sources.

• Journal of the Optical Society of Korea
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• v.18 no.3
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• pp.225-229
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• 2014

A reflection-type three-dimensional (3D) screen using retroreflector is proposed to improve the visibility of a projected 3D image while keeping its perspective. For the projection-type 2D display, the diffuser is used to represent the 2D scene, overcoming the limitation of the aperture of the projection lens set. If the diffuser is adopted for the projected 3D image, only 2D images sectioned and blurred should be displayed on the screen. The proposed screen can make the 3D image with the aperture limitation visible to be applied to the 3D image projection systems. The feasibility of the proposed screen is verified by experiments.

• 전기의세계
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• v.38 no.8
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• pp.9-18
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• 1989

초음파 CT는 시기적으로 가장 빨리 X-ray CT와 함께 연구되어 왔으나 인체내의 투과성, 난반사, 긴파장등에 의해 실용화가 아직은 요원하다. 초음파 CT는 크게 Time of flight (TOF)CT, Attenuation CT, Reflection CT, Diffraction CT등으로 나눌수 있다. 초기에는 TOF CT, Attenuation CT의 연구가 주로 이루어 졌으나 투과의 문제로 인하여 실제로는 유방의 진단에 국한되고 있다. Reflection CT는 초음파의 특성상 실용화가 가장 쉬우나 Transducer 크기등의 문제로 연구가 지연되고 있다. Diffraction CT는 모든 초음파 CT의 특성을 갖고 있으며 현재에 실용화는 요원한 실정이다. KAIST에서는 TOF CT와 Reflection CT의 특징을 결합한 초음파 CT를 연구 발표한 바 있다. 3-D Image은 지금까지의 초음파진단장치에서 표시하는 2-D Image가 갖고 있는 제반의 문제들을 극복하기 위해 현재 KAIST에서 활발히 연구가 진행중에 있다.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.589-592
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• 1997

In this paper, we propose a simple algorithm to calculate the number of passing cars at night by using an image processing sensor for digital black and white images with 256 tone levels. To recognize cars, we capture their head lamps. The reflection of the head lamps is one of the most troublesome factors in recognizing cars. The main problem in this paper is how to recognize cars under the influence of the reflection of the head lamps especially in rainy days. In general, the image of a head lamp is nearly circular and the reflection is long and narrow. On the difference of these forms, we can exclude the reflection in our proposed algorithms For real-time operation and simple calculation, we recognize the existence of cars using fifteen lines with 256 tone levels. In the experimental application on a road, the recognition rate of a real-time operation is more than 90%. Moreover, we will also explain briefly how to recognize passing cars for 24 hours.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.26-27
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• 2012

Reflection considered as the view disturbing noise in optical systems, such as stereo camera in autonomous vehicles especially in night. Reflection caused by the street light or due to rainwater under adverse weather conditions. A blur image detected by the camera that results in wrong guidance to vehicle for detecting its track. A vehicle guidance approach through stereo vision can be same in day and night time. However it cannot be guided with same image analysis due to diverse illumination conditions. We develop the technique that shows its efficacy with illustrations of reflection removal off the camera lens and vehicle tracking control.

• Journal of Korean Elementary Science Education
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• v.32 no.4
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• pp.527-534
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• 2013

This study investigated elementary school teachers' understanding of the image formation by converging lens, pinholes camera, mirror and water. In each case teachers were asked to draw the ray diagram to indicate the position of the image. Teachers' ray diagrams were analyzed in accordance with the scientific process of image formation. Results of analysis showed that teacher's conceptions were classified into five levels for each situation. And most of the teachers were in level 3 and level 4 in each case. Because they had difficulties in the appling scientific conception(propagating path of light, diffused reflection from each object point, role of the eye, ray tracing) to finding location of image. Also most of teachers didn't know how to apply the law of reflection and refraction to each situation. The study finally discussed the teacher training program of the optical image.