2002 Fiscal Year Final Research Report Summary
Research on specification of ROI in LIC visualization
| Project/Area Number |
13680419
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
計算機科学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KOAYAMADA Koji Kyoto University, Associate professor, 学術情報メディアセンター, 助教授 (00305294)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Visualization / Vector field / LIC |
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| Research Abstract |
In this research, we confirmed that a metric "traveling time" is effective in order to specify a region of interest(ROI) in line integral convolution(LIC) visualization by using a flow field which includes a vortex center. Since the original LIC visualization technique processes each pixel in the resulting image evenly, many reseachers focus on the way how the ROI can be specified to visualize the vortex flow field. Especialy, they pay their attention to the representaion of the closeness from the vortex center
We defined a metric of the closeness as a traveling time for a massless particle to arrive at a pixel from near a vortex center. To calculate this traveling time, we reverse the sign of the flow field and give off a massless particle softly. This virtual particle will arrive at the boundary of the flow field or the edge of a computational cell which includes a vortex center. In the latter case, a negative value (-1) is registered at the pixel to indicate that the pixel is not near the vortex center. In the former case, a traveling time from near the vortex center to the pixel is registerd
If we have a flow field which is isotropic around the vortex center, the resulting LIC images are similar even if we use traveling distance or time from the vortex center as a metric of closeness. If we have an anisotropic flow field around the vortex center, we can make the best of the usefulness of the traveling time as the metric. We successfully calculate an LIC image which visualize a typhoon flow field, an anisotropic flow field around the eye of a typhoon. In addition, we extend our LIC technique to three dimension so that we can deal with a general flow field. We apply this 3-D LIC technique to various flow field and confirm its effectivess
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