• Journal of International Society for Simulation Surgery
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• v.1 no.1
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• pp.27-31
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• 2014

In this paper, an overview of segmentation and 3D visualization methods are presented. Commonly, the two kinds of methods are used to visualize organs and vessels into 3D from medical images such as CT(A) and MRI - Direct Volume Rendering (DVR) and Iso-surface Rendering (IR). DVR can be applied directly to a volume. It directly penetrates through the volume while it determines which voxels are visualizedbased on a transfer function. On the other hand, IR requires a series of processes such as segmentation, polygonization and visualization. To extract a region of interest (ROI) from the medical volume image via the segmentation, some regions of an object and a background are required, which are typically obtained from the user. To visualize the extracted regions, the boundary points of the regions should be polygonized. In other words, the boundary surface composed of polygons such as a triangle and a rectangle should be required to visualize the regions into 3D because illumination effects, which makes the object shaded and seen in 3D, cannot be applied directly to the points.

• Journal of the Korea Computer Graphics Society
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• v.20 no.4
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• pp.1-7
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• 2014

The volume rendering has become an important technique in many applications along with hardware development. Understanding and perception of volume visualization benefit from visual cues which are available from shading. Better visual cues can be obtained from global illumination models but it's huge amount of computation and extra GPU memory need cause a lack of interactivity. In this paper, in order to improve visual cues on volume rendering, we propose an image space occlusion shading model which requires no additional resources.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.494-504
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• 2002

Volume rendering is a method of displaying volumetric data as a sequence two-dimensional image. Because this algorithm has an advantage of visualizing structures within objects, it has recently been used to analyze medical images i.e, MRI, PET, and SPECT. In this paper. we suggested a method for creating images easily from sampled volumetric data and applied the interpolation method to medical images. Additionally, we implemented and applied two kinds of interpolation methods to improve the image quality, linear interpolation and cubic interpolation at the sampling stage. Subsequently, we compared the results of volume rendered data using a transfer function. We anticipate a significant contribution to diagnosis through image reconstruction using a volumetric data set, because volume rendering techniques of medical images are the result of 3-dimensional data.

• Journal of Biomedical Engineering Research
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• v.22 no.4
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• pp.339-347
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• 2001

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.67-69
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• 2004

본 논문은 Grid상의 workflow 시스템인 Workflow based Grid Portal for PSE(이하 WISE)를 이용한 인공 심장의 3차원 병렬 volume rendering system 디자인과 구현에 대하여 기술한다. Grid는 전 세계에 분산되어 있는 고성능, 대용량 자원들을 고속 네트워크로 연동하여 사용할 수 있게 하는 환경이며, WISE 시스템은 workflow 개념을 도입하여, 이런 자원들의 효율적이고 편리하게 관리해주고 아울러 여러 가지 패턴을 이용해 프로그래밍 할 수 있게 해주는 middleware이다. 본 논문에서는 Grid 상에서 WISE system에서 제공하는 프로그래밍 패턴을 이용하여 구조화되어 있지 않은 인공심장 데이터를 병렬 processing Pipeline 모델을 바탕으로 효율적인 parallel 3차원 가시화를 하기 위한 parallel pipelined volume rendering system을 구현하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.91-93
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• 2001

볼륨 렌더링(Volume Rendering)은 과학, 의학, 공학 등의 분야에서 3차원 볼륨 데이터(Volume Date)를 효과적으로 시각화(Visualization)하는 목적으로 널리 사용되고 있으며 고화질 영상 요구로 인해 3차원 볼륨 데이터의 크기는 점차 대용량화되어 가는 추세이다. 이러한 대용량 데이터의 고성능 처리를 위해서는 병렬입출력이 필수적이다. 본 논문에서는 병렬볼륨 렌더링에 최적화된 병렬화일시스템 PBS(Parallel Block Server)을 제안한다. PBS는 고성능 입출력 제공을 위해서 데이터입출력에 대한 응용 프로그램의 집적 통제를 위한 다양한 기능을 제공하도록 설계되어 있다. 이러한 직접통제의 단점인 복잡한 인터페이스 문제를 해결하기 위해서 볼륨 렌더링에 최적화된 데이터 입출력 전략을 자동화시킨 PBS 기반 라이브러리 VRPIO(Volume Rendering Parallel Input Output)를 제공한다.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.3_4
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• pp.187-194
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• 2004

Shear-Warp volume rendering has many advantages such as good image Quality and fast rendering speed. However in the interactive classification environment it has low efficiency of memory access since preprocessed classification is unavailable. In this paper we present an algorithm using the spacial locality of memory access in the interactive classification environment. We propose an extension model appending a rotation matrix to the factorization of viewing transformation, it thus performs a scanline-based rendering in the object and image space. We also show causes and solutions of three problems of the proposed algorithm such as inaccurate front-to-back composition, existence of hole, increasing computational cost. This model is efficient due to the spacial locality of memory access.

• Journal of Biomedical Engineering Research
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• v.23 no.6
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• pp.491-498
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• 2002

In medical visualization fields, anisotropic volume data are more common than isotropic ones. In this paper, we propose an efficient rendering method for anisotropic volume data, which directly computes the intensity of intermediate samples by interpolating the intensity of two corresponding voxels on consecutive slices. Unlike conventional rendering method, it does not require a preprocessing step for generating intermediate slices or additional memory for storing them. In order to evaluate the validity and performance of our method, we applied the method to shear-warp rendering algorithm. Experimental results show that this method improves rendering speed without significantly sacrificing the image quality.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.101-106
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• 2014

The era came that by having fastest internet and smart phone makes cloud computing really a big merit. This paper proposes architecture for medical image volume rendering in mobile environment using cloud computing. This architecture to replace expensive workstation server and storage it use one of the service of cloud computing IaaS(Infrastructure as a Service). And this paper propose to use webGL to get rid of restriction of mobile hardware. By this research, it is expected that medical image volume rendering service in mobile environment is more effective and can be a foundation work.

• Journal of Korea Multimedia Society
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• v.8 no.9
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• pp.1239-1247
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• 2005

Basically, objects are discriminated by transfer functions in volume rendering . However, in some cases objects cannot be discriminated only with transfer functions. In these cases, objects are pre-segmented with other methods, and visualized based on the segmentation information. In this paper we present a way of assigning per-object transparency in visualization of segmented volumes. Semi-transparent rendering is used to effectively give context information about the observed object. Per-object transparency can be used as a very effective visualization tool especially when it is difficult to adjust transfer functions to make the object semi-transparent. We present several interpretations of the meaning of per-object transparency, and corresponding variations of the algorithm. We show that efficient implementations for interactive use are possible, by presenting an implementation using general graphics hardware.