• Title/Summary/Keyword: Volume Rendering

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Volume Rendering Using Multi-Textures (Multi-Textures를 이용한 Volume Rendering)

  • 박재영;이병일;최흥국
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • pp.169-172
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    • 2000
  • Direct volume rendering has yet been restricted to high-end graphic workstations and special-purpose hardware, due to the large amount of trilinear interpolation, that are necessary to obtain high image quality. In this paper, we implemented the volume rendering techniques using the 2D-texture at the environment of standard PC hardware. In addition, we show how multi-texturing capabilities of modern PC graphics board are enable to volume rendering. Besides using extended OpenGL function, we improved pixel operations and rendering capacity.

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Visualization of three-dimensional medical information based on Shear-Warp Volume Rendering (Shear-Warp Volume Rendering에 의한 3차원 의료영상 정보 표현)

  • Chae Eunmi;Huh Junsung;Sah Jongyoub
    • 한국전산유체공학회:학술대회논문집
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    • pp.158-162
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    • 1999
  • This thesis presents applications of three dimensional visualization technique based on shear-warp volume rendering to medical information. Volume rendering is compared to surface rendering and acceleration technique is also presented. The presented rendering techniques by using three-dimensional arrays of data are a widely used representation for computational fluid dynamics and geological structures as well as medical information.

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A Block-Based Volume Rendering Algorithm Using Shear-Warp factorization (쉬어-왑 분해를 이용한 블록 기반의 볼륨 렌더링 기법)

  • 권성민;김진국;박현욱;나종범
    • Journal of Biomedical Engineering Research
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    • v.21 no.4
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    • pp.433-439
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    • 2000
  • Volume rendering is a powerful tool for visualizing sampled scalar values from 3D data without modeling geometric primitives to the data. The volume rendering can describe the surface-detail of a complex object. Owing to this characteristic. volume rendering has been used to visualize medical data. The size of volume data is usually too big to handle in real time. Recently, various volume rendering algorithms have been proposed in order to reduce the rendering time. However, most of the proposed algorithms are not proper for fast rendering of large non-coded volume data. In this paper, we propose a block-based fast volume rendering algorithm using a shear-warp factorization for non-coded volume data. The algorithm performs volume rendering by using the organ segmentation data as well as block-based 3D volume data, and increases the rendering speed for large non-coded volume data. The proposed algorithm is evaluated by rendering 3D X-ray CT body images and MR head images.

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An Efficient Volume Rendering for Dental Diagnosis Using Cone Beam CT data (치과 원추형 CT 영상 데이터 분석에 효율적인 볼륨 렌더링 방법)

  • Koo, Yun Mo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.1
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    • pp.55-64
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    • 2012
  • The advantage of direct volume rendering is to visualize structures of interest in the volumetric data. However it is still difficult to simultaneously show interior and exterior structures. Recently, cone beam computed tomography(CBCT) has been used for dental diagnosis. Despite of its usefulness, there is a limitation in the detection of interior structures such as pulp and inferior alveolar nerve canal. In this paper, we propose an efficient volume rendering model for visualizing important interior as well as exterior structures of dental CBCT. It is based on the concept of illustrative volume rendering and enhances boundary and silhouette of structures. Moreover, we present a new method that assigns a different color to structures in the rear so as to distinguish the front ones from the rear ones. This proposed rendering model has been implemented on graphics hardware, so that we can achieve interactive performance. In addition, we can render teeth, pulp and canal without cumbersome segmentation step.

Improvement Depth Perception of Volume Rendering using Virtual Reality (가상현실을 통한 볼륨렌더링 깊이 인식 향상)

  • Choi, JunYoung;Jeong, HaeJin;Jeong, Won-Ki
    • Journal of the Korea Computer Graphics Society
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    • v.24 no.2
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    • pp.29-40
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    • 2018
  • Direct volume rendering (DVR) is a commonly used method to visualize inner structures in 3D volumetric datasets. However, conventional volume rendering on a 2D display lacks depth perception due to dimensionality reduction caused by ray casting. In this work, we investigate how emerging Virtual Reality (VR) can improve the usability of direct volume rendering. We developed real-time high-resolution DVR system in virtual reality, and measures the usefulness of volume rendering with improved depth perception via a user study conducted by 38 participants. The result indicates that virtual reality significantly improves the usability of DVR by allowing better depth perception.

Volume Rendering using Grid Computing for Large-Scale Volume Data

  • Nishihashi, Kunihiko;Higaki, Toru;Okabe, Kenji;Raytchev, Bisser;Tamaki, Toru;Kaneda, Kazufumi
    • International Journal of CAD/CAM
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    • v.9 no.1
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    • pp.111-120
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    • 2010
  • In this paper, we propose a volume rendering method using grid computing for large-scale volume data. Grid computing is attractive because medical institutions and research facilities often have a large number of idle computers. A large-scale volume data is divided into sub-volumes and the sub-volumes are rendered using grid computing. When using grid computing, different computers rarely have the same processor speeds. Thus the return order of results rarely matches the sending order. However order is vital when combining results to create a final image. Job-Scheduling is important in grid computing for volume rendering, so we use an obstacle-flag which changes priorities dynamically to manage sub-volume results. Obstacle-Flags manage visibility of each sub-volume when line of sight from the view point is obscured by other subvolumes. The proposed Dynamic Job-Scheduling based on visibility substantially increases efficiency. Our Dynamic Job-Scheduling method was implemented on our university's campus grid and we conducted comparative experiments, which showed that the proposed method provides significant improvements in efficiency for large-scale volume rendering.

Exploiting Programmable Shaders in Hardware-Assisted Volume Rendering (PC용 그래픽스 가속기의 쉐이더 기능을 이용한 볼륨 렌더링)

  • Im, In-Seong;Gang, Byeong-Gwon
    • Journal of the Korea Computer Graphics Society
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    • v.8 no.2
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    • pp.23-29
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    • 2002
  • In this paper, we describe an implementation technique that extends the classification and shading capabilities offered by previously reported hardware-assisted volume rendering algorithms. In designing our rendering scheme, we exploited the programmable shader technology supported by the latest consumer PC graphics hardware. Our direct volume rendering technique enables to simultaneously display up to four materials, and to dynamically control gradient magnitude to emphasize or de-emphasize surface boundaries. It can easily create lighting effects such as light source attenuation, depth cueing, and multiple light sources that were often difficult to realize in previous hardware-assisted volume rendering.

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Load Balanced Volume Rendering System for Concurrent Users in Multi-CPU Server Environment (다중 CPU 서버 환경에서 동시 사용자를 위한 부하조절 기반 볼륨 가시화 시스템)

  • Lee, Woongkyu;Kye, Heewon
    • Journal of Korea Multimedia Society
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    • v.18 no.5
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    • pp.620-630
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    • 2015
  • This research suggests a load balancing method for a volume rendering system which supports concurrent users. When concurrent users use a volume rendering server system, the computational resources are occupied by a particular user by turns because each process consumes the computational resources as much as possible. In this case, the previous method shows acceptable throughput but the latency is increased for each user. In this research, we suggest a method to improve the latency without performance degradation. Each process makes concessions for taking the resources according to the number of users connected to the system. And we propose a load balancing method in the dynamic situation in which the number of users can vary. Using our methods, we can improve the latency time for each user.

Volume Rendering by Improved Ray Casting (개선된 광선 추적에 의한 볼륨 랜더링)

  • Kim, Hyeong-Gyun;Kim, Yong-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.662-665
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    • 2005
  • 본 논문에서는 체적 데이터에 대한 효율적인 볼륨 랜더링을 수행하기 위해서, 기존의 광선 추적 기법에 대해 광선 보간을 통해서 광선을 추적하는 기법인 IRCF를 제안한다. IRCF 과정은 이웃 화소에 대한 광선추적을 통해 얻은 불투명도값의 정보를 이용해 현재 광선 추적 위치와 불투명도값을 보간한 위치에서 새롭게 광선 추적을 해가는 방식이다. 기존의 고화질의 광선 추적 랜더링의 경우 Volume Rendering Operations의 계샨량이 많아 그 만큼 랜더링 속도가 떨어져 체적에 대해 다른 개선된 랜더링 기법들이 많이 제안되고 있다. 본 논문은 다른 각도로의 접근하고자 제안한 기법을 통해 Volume Rendering Operations의 계샨량을 최대한 줄임으로 랜더링 속도를 높이고 기본의 고화질 영상에 가까운 결과을 얻을 수가 있었다. 또한, 본 논문에서는 기존의 광선 추적 기법에서 표현하는 일반적인 회전, 절단, 불투명 등 제어 효과들을 제안한 기법을 통해 비교 분석한다.

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Improved Sampling Method For Volume Rendering (Volume Rendering를 위한 향상된 Sampling 방법)

  • 박재영;이병일;최흥국
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • pp.213-216
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    • 2000
  • 본 논문에서는 volume rendering 기법을 이용하여 2차원 MRI 영상들을 합성하여 3차원 영상 만들 때 보다 해상도를 높이기 위한 개선된 sampling방법을 소개한다 2차원 슬라이스 영상들이 3차원으로 재구성할 때 voxel 기반으로 렌더링을 하기 때문에 오브젝트의 내부 영역까지도 볼 수 있는 것이 volume rendering의 가장 큰 장점이다. 따라서 영상을 재구성하는 과정에서 보다 향상된 interpolation을 적용시켜서 공간 해상도를 향상시키면 보다 명확하게 오브젝트 내부 정보를 살펴 볼 수 있다. 본 논문에서는 nearest neighbor 이나 linear 같은 interpolation으로 sampling한 방법보다 cubic interpolation을 3차원 공간에서 적용 시켜서 보다 resampling이 잘 되도록 하여 해상도를 향상시켜 보았다. 이렇게 향상된 Interpolation 적용시켜서 렌더링할 때 얼마나 오브젝트 내부 영역이 잘 가시화가 되었는지 transfer function을 적용시켜서 오브젝트 내부 정보를 렌더링 해보았고, 임의의 축으로 오브젝트을 잘라서 2D 단면 영상으로 출력해 보았다. 보다 향상된 interpolation을 적용시켜서 resampling을 하면 영상 해상도가 개선되었음을 볼 수 있었다.

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