• Journal of Korea Game Society
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• v.7 no.4
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• pp.71-80
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• 2007

In this paper, we introduce an efficient GPU-based real-time rendering technique applicable to every kind of game. Our method, without an extra geometry, can represent terrain just with a height map. It makes it possible to freely go around in the air or on the surface, so we can directly apply it to any computer games as well as a virtual reality. Since our method is not based on any geometrical structure, it doesn't need special LOD policy and the precision of geometrical representation and visual quality absolutely depend on the resolution of height map and color map. Moreover, GPU-only technique allows the general CPU to be dedicated to more general work, and as a result, enhances the overall performance of the computer. To date, there have been many researches related to the terrain representation, but most of them rely on CPU or confmed its applications to flight simulation, Improving existing displacement mapping techniques and applying it to our terrain rendering, we completely ruled out the problems, such as cracking, poping etc, which cause in polygon-based techniques, The most important contributions are to efficiently deal with arbitrary LOS(Line Of Sight) and dramatically improve visual quality during walk-through by reconstructing a height field with curved patches. We suggest a simple and useful method for calculating ray-patch intersections. We implemented all these on GPU 100%, and got tens to hundreds of framerates with height maps a variety of resolutions$(256{\times}256\;to\;4096{\times}4096)$.

• Archives of design research
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• v.19 no.1 s.63
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• pp.79-88
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• 2006

A human face figure is a visual symbol of identity. Each different face per person is a critical information differentiating each person from others and it directly relates to individual identity. When we look back human history, historical change of recognition for a face led to the change of expression and communication media and it in turn caused many changes in expressing a face. However, there has not been no time period when people pay attention to a face more than this time. Technically, the advent of computer graphics opened new turning point in expressing human face figure. Especially, a visual image which can be produced, saved, and transferred in digital has no limitation in time and space, and its importance in communication is getting higher and higher. Among those visual image information, a face image in digital is getting more applications. Therefore, 3d (3-dimensional) expression of a face using computer graphics can be easily produced without any professional techniques, just like assembling puzzle parts composed of the shape of each part ands texture map, etc. This study presents a method with which a general visual designer can effectively express 3d type face by studying each producing step of 3d face expression and by visualizing case study based on the above-mentioned study result.

• Journal of Korea Game Society
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• v.12 no.5
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• pp.67-78
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• 2012

Summed area table allows filtering of arbitrary-width box regions for every pixel in constant time per pixel. This characteristic makes it beneficial in image processing applications where the sum or average of the surrounding pixel intensity is required. Although calculating the summed area table of an image data is primarily a memory bound job consisting of row or column-wise summation, previous works had to endure excessive access to the high latency global memory in order to exploit data parallelism. In this paper, we propose an efficient algorithm for generating the summed area table in the GPGPU environment where the input is decomposed into square sub-images with intermediate data that are propagated between them. By doing so, the global memory access is almost halved compared to the previous methods making an efficient use of the available memory bandwidth. The results show a substantial increase in performance.

• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.362-373
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• 2020

Recently, as autonomous vehicles and intelligent CCTV are growing more interest, the efficient object detection is essential technique. The DPM(Deformable Part Models) which is basis of this paper have used a typical object system that represents highly variable objects using mixtures of deformable part for object. Although it shows high detection performance by capturing part shape and configuration of object model, but it is limited to use in real application due to the complicated algorithm. In this paper, instead of image feature pyramid that takes up a large amount of computation in one part of the detector, we propose a method to reduce the computation speed by reconstructing a new image feature pyramid that uses adaptive bilinear interpolation of feature maps obtained on a specific image scale. As a result, the detection performance for object was lowered a little by 2.82%, however, the proposed detection method improved the speed performance by 10% in comparison with original DPM.

• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.20-25
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• 2016

With the advent of the era of digital big data, the Hadoop platform has become widely used in various fields. However, the Hadoop MapReduce framework suffers from problems related to the increase of the name node's main memory and map tasks for the processing of large number of small files. In addition, a method for running C++-based tasks in the MapReduce framework is required in order to conjugate GPUs supporting hardware-based data parallelism in the MapReduce framework. Therefore, in this paper, we present a face detection system that generates a sequence file for images to process big data for images in the Hadoop platform. The system also deals with tasks for GPU-based face detection in the MapReduce framework using Hadoop Pipes. We demonstrate a performance increase of around 6.8-fold as compared to a single CPU process.

• Journal of the Korea Computer Graphics Society
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• v.6 no.4
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• pp.1-7
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• 2000

Traditionally, three dimension model s have been used for building virtual worlds, and a data structure called the "scene graph" is often employed to organize these 3D objects in the virtual space. On the other hand, image-based rendering has recently been suggested as a probable alternative VR platform for its photo-realism, however, due to limited interactivity. it has only been used for simple navigation systems. To combine the merits of these two approaches to object/scene representations, this paper proposes for a scene graph structure in which both 3D models and various image-based scenes/objects can be defined. traversed, and rendered together. In fact, as suggested by Shade et al. [1]. these different representations can be used as different LOD's for a given object. For in stance, an object might be rendered using a 3D model at close range, a billboard at an intermediate range. and as part of an environment map at far range. The ultimate objective of this mixed platform is to breath more interactivity into the image based rendered VE's by employing 3D models as well. There are several technical challenges in devising such a platform : designing scene graph nodes for various types of image based techniques, establishing criteria for LOD/representation selection. handling their transition s. implementing appropriate interaction schemes. and correctly rendering the overall scene. Currently, we have extended the scene graph structure of the Sense8's WorldToolKit. to accommodate new node types for environment maps. billboards, moving textures and sprites, "Tour-into-the-Picture" structure, and view interpolated objects. As for choosing the right LOD level, the usual viewing distance and image space criteria are used, however, the switching between the image and 3D model occurs at a distance from the user where the user starts to perceive the object's internal depth. Also. during interaction, regardless of the viewing distance. a 3D representation would be used, if it exists. Finally. we carried out experiments to verify the theoretical derivation of the switching rule and obtained positive results.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.613-615
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• 2005

모바일 기기가 가지는 다양한 화면 사이즈 등을 고려한 정보 서비스를 제공하기 위해서는 비트맵 기반의 JPG나 GIF 보다는 벡터 기반의 SVG, Flash Lite와 같은 이미지 포맷이 더 적합하다. 대부분의 모바일 기기의 경우 작은 메모리, 협소한 네트워크 대역폭, 불안전한 네트워크 연결 등과 같은 제약성을 가지고 있기 때문에 모바일 기기와 서버 간의 정보나 데이터의 망과 전송 시간을 단축시키기 위한 다양한 연구들이 진행되고 있다. 이에 본 논문에서는 모바일 기기에서 정보를 표현하기 위하여 사용되는 SVG와 같은 XML 파일들을 효과적으로 전송하기 위한 방법을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.748-750
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• 2005

본 논문은 오목한 물체의 그림자 표현이 가능한 그림자 텍스처를 생성하기 위해, 기존의 그림자 맵 (shadow MaP) 방법으로 그림자 정보를 생성하고 아틀라스 텍스처 (atlas texture)에 저장하는 방법을 제안한다. 기존 그림자 텍스처 방법은 그림자 정보를 이미지 텍스처에 저장하므로 그래픽스 하드웨어의 색상 처리 기능을 사용하여 고품질의 그림자를 효율적으로 표현하는 장점이 있지만 오목한 물체의 그림자를 표현하지 못하고 그림자 텍스처 생성에 많은 시간이 소요되는 문제점을 가지고 있다. 실험 결과, 새로운 방법은 그림자 텍스처의 문제점을 해결하고 고품질의 그림자를 표현하는 것을 알 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.102-105
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• 2015

본 논문에서는 멀티미디어 및 수학 관련 알고리즘 분야에서 각광 받고 있는 CUDA(Compute Unified Device Architecture) 기법을 실시간 동영상 자막 처리에 이용 한다. 실시간 고화질 동영상 자막 처리의 낮은 속도를 개선하기 위한 방법 제안으로 써, 이의 함수 구성을 제안한다. 기존의 자막 처리 방식에서는 하나의 코어만을 이용하였다. 이 방법 대신에 CUDA 를 적용 함으로써, 더 많은 코어를 이용해 실시간 자막 처리의 지각적인 성능을 향상하였다. 삽입하고자 하는 자막에 대해 비트맵 이미지를 형성하고, 이의 정보를 처리한다. Intel $Core^{TM}$ i7-4710 MQ, GTX870 환경에서 실험하였으며, 실험 결과 C code 만으로 연산을 한 것 보다 CUDA code 가 약 88% 정도의 속도 향상이 있음을 보였다.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.181-184
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• 2007

자연영상에 포함된 텍스트는 많은 중요한 정보를 포함하고 있으므로 자연영상에서 텍스트 정보를 검출하는 연구가 활발히 진행되고 있다. 본 논문에서는 문자 영역의 구조적인 특정을 배열문법으로 정의한 적응적 문자-에지 맵을 제안하여 텍스트 영역을 검출한다. 캐니-에지 검출기로 에지를 추출하고, 생성된 에지 이미지를 레이블링하고 그 영역의 문자구조 특징을 분석하기 위해서 적응적 문자-에지 맵을 분석한다. 적응적 문자-에지 랩의 분포 상태를 분석함으로서 텍스트 후보 영역을 검출하고, 텍스트 영역의 에지 히스토그램 프로파일을 분석함으로서 텍스트 후보 영역에 대한 검증을 수행하여 최종적인 텍스트 영역을 검출한다. 제안한 방법은 다양한 종류의 자연영상을 대상으로 실험하였고, 기울어진 텍스트와 다양한 크기의 텍스트 구성된 자연영상에서 텍스트 영역을 효과적으로 검출하였다.