• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.339-347
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• 2011

As the volume visualization has been applied to render medical datasets, there has been a requirement to produce high quality images. Even though nice images can be generated by using previous linear filter, high order filter is required for better images. However, it takes much time for high order resampling, so that, overall rendering time is increased. In this paper, we perform high quality volume visualization using the cardinal interpolation. By enabling the empty space leaping which reduces the number of resampling, we achieve the efficient visualization. In detail, we divide the volume data into small blocks and leap empty blocks by referring the upper and lower bound value for each block. We propose a new method to estimate upper and lower bound value of for each block. As the result, we noticeably accelerated high quality volume visualization.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.921-931
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• 2011

This paper presents a data-fitting technique in which a B-spline hypervolume is used to approximate a given data set of scattered data samples. We describe the implementation of the data structure of a B-spline hypervolume, and we measure its memory size to show that the representation is compact. The proposed technique includes two algorithms. One is for the determination of the knot vectors of a B-spline hypervolume. The other is for the control points, which are determined by solving a linear least-squares minimization problem where the solution is independent of the data-set complexity. The proposed approach is demonstrated with various data-set configurations to reveal its performance in terms of approximation accuracy, memory use, and running time. In addition, we compare our approach with existing methods and present unconstrained optimization examples to show the potential for various applications.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.46-48
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• 2002

사용자에게 서비스 할 데이터가 많을 경우 여러 볼륨에 저장해서 처리해야 할 경우가 발생한다. 볼륨이 여러 개일 경우 효과적이고 효율적인 접근 방법이 필요하다. 본 논문에서는 SHORE 저장 시스템을 이용할 경우에 효과적이고 효율적인 접근 방법을 알아보고자 한다. single thread, multi thread, multi process, socket을 이용한 접근 방법을 살펴보고 multi thread를 이용하는 방법이 가장 효율적인 것을 실험 결과를 통해서 보인다. SHORE thread는 CPU bound에 관련된 job이 많은 경우는 process를 사용했을 때에 비해 큰 효과가 없으나 I/O bound에 관련에 것일 경우는 multi process를 사용한 것과 비슷한 효과가 있음을 알 수 있다.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.9-17
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• 2011

Recently, with the advent of stereoscopic 3D TV, the activation of 3D stereoscopic content is expected. Research on 3D auto stereoscopic display has been carried out to relieve discomfort of 3D stereoscopic display. In this research, it is necessary to generate the elemental image from a lens array. As the number of lens in a lens array is increased, it takes a lot of time to generate the elemental image, and it will take more time for a large volume data. In order to improve the problem, in this paper, we propose a method to generate the elemental image by using OpenCL based on CUDA. We perform our proposed method on PC environment with one of Tesla C1060, Geforce 9800GT and Quadro FX 3800 graphics cards. Experimental results show that the proposed method can obtain almost 20 times better performance than recent research result[11].

• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.409-417
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• 1999

Talairach atlas consists of three orthogonal sets of coronal, sagittal, and axial slices. This atlas has recently an important role as a standard brain atlas in diagnosing disease related with brain function and analyzing cause of brain disease. The 3D digital volume data set reconstructed from the atlas is widely applied to visualization and quantitative analysis of results processed in the digital computer. This paper represented application method of bi-linear interpolation technique, proposed tri-planar interpolation algorithm for 3D volume data reconstruction of Talairach atlas. And we implemented Talairach atlas editor and discussed problems in volume reconstruction of Talairach atlas. The bi-linear method was applied to only one set of the slices and considered the on intensity value in the interpolation process. The tri-planar technique concurrently uses three orthogonal sets of slices with the same information of brain structures. Talairach atlas editor visualized three sets. of atlas slices on the same coordinate and had editing function. Using the atlas editor, we represented problems in volume reconstruction by showing inconsistency of brain structures among three sets of atlas slices.

• Journal of the Korea Computer Graphics Society
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• v.23 no.3
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• pp.87-94
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• 2017

Due to improvements in the capabilities of commercial game engines, there are increasing instances of applying game engines to scientific visualization applications. This study describes a case of creating a virtual reality application that visualizes medical volume data based on the Unity3D game engine. When using a game engine, there is an advantage that various functions required for an application are basically provided, such as depth sorting of translucent objects or virtual reality hardware support. On the other hand, there is a restriction that the structure of the application program should be modified to suit the characteristics of the game engine. This paper describes a method for visualizing medical volume data using the structure of a game engine. As a result, we were able to create a virtual reality scene that consisted of surface data and medical volume data fragments together. And we confirmed the possibility of game engine as a future medical simulation production tool.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.253-256
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• 2001

본 논문에서는 전처리 과정에서 잡음의 효과적 처리를 위해 기존의 필터 방식들이 가지는 단점인 경계 부분의 블러링 현상을 줄이고 정확한 에지 위치를 보존할 수 있는 비등방성 확산 필터를 사용하여 CT나 MRI 2차원 영상 슬라이스들을 만들어내고 이 슬라이스들을 3차원 데이터 셋으로 구성하여 3차원 공간의 볼륨 데이터로 시각적인 영상정보를 얻는데 있다.

• Journal of Korea Game Society
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• v.9 no.4
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• pp.89-96
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• 2009

In general, the size of volume data is large since it has logical 3D structure so it takes long time to manipulate. Much work has been done to improve processing speed of volume data. In this paper, we propose a interlaced scanning volume rendering that reduce computation time by using temporal coherence with minimum loss of image quality. It renders a current frame by reusing information of previous frame. Conventional volume raycasting renders each frame by casting rays on every pixels. On the other hand, our methods divided an image into n-pixel blocks, then it casts a ray on a pixel of a block per each frames. Consequently, it generates an image by accumulating pixel values of previous n frames. The quality of rendered image of our method is better than that of simple screen space subsampling method since it uses afterimage effect of human cognitive system, and it is n-times faster that the previous one.

• Journal of Korea Multimedia Society
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• v.14 no.10
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• pp.1229-1237
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• 2011

The volume ray-casting method is one of the direct volume rendering methods that produces high-quality images as well as manipulates semi-transparent object. Although the volume ray-casting method produces high-quality image by sampling in the region of interest, its rendering speed is slow since the color acquisition process is complicated for repetitive memory reference and accumulation of sample values. Recently, the GPU-based acceleration techniques are introduced. However, they require pre-processing or additional memory. In this paper, we propose efficient point-primitive based method to overcome complicated computation of GPU ray-casting. It presents semi-transparent objects, however it does not require preprocessing and additional memory. Our method is fast since it generates point-primitives from volume dataset during sampling process and it projects the primitives onto the image plane. Also, our method can easily cope with OTF change because we can add or delete point-primitive in real-time.

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1620-1632
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• 1998

This paper presents a fast parallel algorithm for volume rendering and its implementation using C language and MPI MasPar Programming Language) on the 4,096 processor MasPar MP-2 machine. This parallel algorithm is a parallelization hased on the Lacroute' s sequential shear - warp algorithm currently acknowledged to be the fastest sequential volume rendering algorithm. This algorithm reduces communication overheads by using the sheared space partition scheme and the load balancing technique using load estimates from the previous iteration, and the number of voxels to be processed by using the run-length encoded volume data structure.Actual performance is 3 to 4 frames/second on the human hrain scan dataset of $128\times128\times128$ voxels. Because of the scalability of this algorithm, performance of ]2-16 frames/sc.'cond is expected on the 16,384 processor MasPar MP-2 machine. It is expected that implementation on more current SIMD or MIMD architectures would provide 3O~60 frames/second on large volumes.