• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.135-138
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• 2006

본 논문에서는 텍스처 매핑을 처리하기 위한 텍스처 유닛 하드웨어 설계에 효율적인 새로운 유동형 소수점 포맷을 제안한다. 기존 고정 소수점 포맷은 하드웨어가 간단한 반면 고품질 텍스처 처리를 수행할 경우 오버플로우/언더플로우가 발생하며 부동 소수점 포맷은 이를 해결할 수 있으나 하드웨어가 복잡하다. 제안한 방식은 오버플로우/언더플로우를 해결하면서 부동소수점보다 하드웨어 크기를 줄여서 본 포맷을 적용한 가산기는 부동소수점보다 26% 작으며 곱셈기는 고정/부동 소수점보다 절반 이상으로 작다. 따라서 제안한 포맷은 100Mhz 이상의 빠른 동작이 가능하며 모바일 3차원 그래픽 가속기의 텍스처 유닛 설계에 효과적이다.

• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.123-133
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• 2011

In this paper, we propose a new method for toon shading using 3D texture which renders 3d objects in a cartoon style. The conventional toon shading using 1D texture displays shading tone by computing the relative position and orientation between a light vector and surface normal. The 1D texture alone has limits to express the various tone change according to any viewing condition. Therefore Barla et. al. replaces a 1D texture with a 2D texture whose the second dimension corresponds to the view-dependent effects such as level-of-abstraction, depthof-field. The proposed scheme extends 2D texture to 3D texture by adding one dimension with the geometric information of 3D objects such as curvature, saliency, and coordinates. This approach supports two kinds of extensions for cartoon style diversification. First, we support "shape exaggeration effect" to emphasize silhouette or highlight according to the geometric information of 3D objects. Second, we further incorporate "cartoon specific effect", which is examples of screen tone and out focusing frequently appeared in cartoons. We demonstrate the effectiveness of our approach through examples that include a number of 3d objects rendered in various cartoon style.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.388-390
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• 2012

도시 지역의 영상에서는 가로수, 행인, 자동차 등 3차원 대상이 아닌 전경 물체가 빈번하게 나타남에 따라 건물 모델의 텍스처 생성에 어려움이 있다. 따라서 본 논문은 건물 영상에서 전경 물체에 의한 가림이 제거된 정명평행 텍스처를 생성하는 방법을 제안한다. 제안하는 방법은 사용자 조작을 이용하여 반자동으로 전경 물체에 의해 가려진 영역을 찾고, 이를 인페인팅 기법을 통해 채워넣음으로서 facade에 대한 텍스처를 생성한다.

• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.109-118
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• 2008

In mapping a texture image into a 3D mesh model for photo-realistic graphic applications, the compression of texture image is as important as geometry of 3D mesh. Typically, the size of the (compressed) texture image of 3D model is comparable to that of the (compressed) 3D mesh geometry. Most 3D model compression techniques are to compress the 3D mesh geometry, rather than to compress the texture image. Well-known image compression standards (i.e., JPEG) have been extensively used for texture image compression. However, such techniques are not so efficient when it comes to compress an image with texture patches, since the patches are little correlated. In this paper, we proposed a preprocessing method to substantially improve the compression efficiency of texture compression. From the experimental results, the proposed method was shown to be efficient in compression with a bit-saving from 23% to 45%.

• Journal of Advanced Navigation Technology
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• v.13 no.1
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• pp.142-150
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• 2009

It is very important to generate a simplified model from a complex 3D character in computer game. We propose a new method of extracting feature lines from a 3D game character. Given an unstructured 3D character model containing texture information, we use model feature map (MFM), which is a 2D map that abstracts the variation of texture and curvature in the 3D character model. The MFM is created from both a texture map and a curvature map, which are produced separately by edge-detection to locate line features. The MFM can be edited interactively using standard image-processing tools. We demonstrate the technique on several data sets, including, but not limited to facial character.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.3
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• pp.160-174
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• 2008

In this paper, we propose new coding techniques for photometry data of three-dimensional(3-D) mesh models. We make a good use of geometry and connectivity information to improve coding efficiency of color, normal vector, and texture data. First of all, we determine the coding order of photometry data exploiting connectivity information. Then, we exploit the obtained geometry information of neighboring vortices through the previous process to predict the photometry data. For color coding, the predicted color of the current vertex is computed by a weighted sum of colors for adjacent vortices considering geometrical characteristics between the current vortex and the adjacent vortices at the geometry predictor. For normal vector coding, the normal vector of the current vertex is equal to one of the optimal plane produced by the optimal plane generator with distance equalizer owing to the property of an isosceles triangle. For texture coding, our proposed method removes discontinuity in the texture coordinates and reallocates texture image segments according to the coding order. Simulation results show that the proposed compression schemes provide improved performance over previous works for various 3-D mesh models.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.545-556
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• 2015

A HEVC-compatible 3D video coding method (3D-HEVC) has been recently developed as an extension of the high efficiency video coding (HEVC) standard. In order to efficiently deal with the multi-view video plus depth (MVD) format, 3D-HEVC exploits an inter-component prediction which allows the prediction between texture and depth map images in addition to a temporal prediction used in the conventional single layer video coding such as H.264/AVC and HEVC. The performance of the inter-component prediction is normally affected by the accuracy of the disparity vector, and thus it is important to have an accurate disparity vector used for the inter-component prediction. This paper, therefore, introduces a disparity derivation method and inter-component algorithms using the disparity vector for the efficient 3D video coding. Simulation results show that the 3D-HEVC provides higher coding performance compared with the simulcast approach using HEVC and the simple multi-view extension (MH-HEVC).

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.497-498
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• 2012

지형 분류는 원격 로봇이 처한 환경에서 오브젝트의 종류를 표시한 지도를 만들 수 있게 한다. 우선 2D 및 3D 데이터셋으로부터 텍스처를 매핑한 지형 메쉬를 생성하였다. 그 후 지형 메쉬에서 수평 공간적 분포를 기반으로 건물 및 나무를 분류하는 방법을 제안한다. 옥외 환경에서 이 방법을 적용하여 실험을 수행하였으며, 텍스처를 매핑한 지형 메쉬에서 건물과 나무를 성공적으로 분류할 수 있음을 확인하였다.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.37-44
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• 2006

Specular reflections provide the visual feedback that describes the material type of an object, its local shape, and lighting environment. In photorealistic rendering, there have been a number of research available to render specular reflections effectively based on a local reflection model. In traditional cel animations and cartoons, specular reflections plays important role in representing artistic intentions for an object and its related environment reflections, so the shapes of highlights are quite stylistic. In this paper, we present a method to render and control stylized specular reflections using projective textures based on principal curvature analysis. Specifying a texture as a pattern of a highlight and projecting the texture on the specular region of a given 3D model, we can obtain a stylized representation of specular reflections. For a given polygonal model, a view point, and a light source, we first find the maximum specular intensity point, and then locate the texture projector along the line parallel to the normal vector and passing through the point. The orientation of the projector is determined by the principal directions at the point. Finally, the size of the projection frustum is determined by the principal curvatures corresponding to the principal directions. The proposed method can control the position, orientation, and size of the specular reflection efficiently by translating the projector along the principal directions, rotating the projector about the normal vector, and scaling the principal curvatures, respectively. The method is be applicable to real-time applications such as cartoon style 3D games. We implement the method by Microsoft DirectX 9.0c SDK and programmable vertex/pixel shaders on Nvidia GeForce FX 7800 graphics subsystems. According to our experimental results, we can render and control the stylized specular reflections for a 3D model of several ten thousands of triangles in real-time.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.25-27
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• 2002

본 논문에서는 3차원 그래픽의 래스터라이제이션 단계에서 발생하는 메모리 트래픽 문제를 해결하기 위해 사용되는 텍스처 및 픽셀 캐쉬에 대한 성능을 분석하였다. 이를 위해 화면의 해상도, 컬러 정보, 깊이 정보 및 캐쉬 구성의 변화에 따른 이들 캐쉬의 성능변화를 살펴보았으며 실험결과 텍스처 캐쉬와 픽셀 캐쉬의 설계 시에 블록 크기에 의한 영향이 매우 중요함을 알 수 있었다. 특히 픽셀 캐쉬의 경우에는 시간적 지역성은 거의 없으며 매우 큰 공간적 지역성을 보이므로 이를 잘 반영할 수 있는 캐쉬 구조가 필요하다.