Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.
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Transcript of Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.
![Page 1: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/1.jpg)
Tracking a selected point in vector field
Liefei (Lucy) XuOct 2008
![Page 2: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/2.jpg)
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Track a point:
Select a point
Find the most similar point in later slices (how?)
Tracking a point through time
![Page 3: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/3.jpg)
Measure similarity between points
1. Extract attributes of each point- Vector Spin image
2. Compute similarity based on the attributes- χ2 statistic distance
![Page 4: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/4.jpg)
Test and adjustment
• We test and adjust our algorithm on below parameters:– Different types of selected point:
singularities, ridges, regular points
– Different attributes for spin image: vector direction, vector magnitude, strength of rotation, strength of dilation, strength of stretch, direction of stretch, tensor magnitude
– Different radius of spin image: 2*20, 5*60, 8*120
![Page 5: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/5.jpg)
Selected Result tracking a singularity
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Vector Direction Strength of dilation Tensor magnitude
![Page 6: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/6.jpg)
Selected Result tracking a regular point
Vector Direction Strength of dilation Tensor magnitude
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![Page 7: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/7.jpg)
Selected Result tracking a point on ridge
Vector Direction Strength of dilation Tensor magnitude
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![Page 8: Tracking a selected point in vector field Liefei (Lucy) Xu Oct 2008.](https://reader036.fdocuments.us/reader036/viewer/2022081513/56649d575503460f94a354fb/html5/thumbnails/8.jpg)
Uniqueness and Strength
Topological method Our Statistic method
A lot of research has been done
A novel method
Depends on singularities Works for both singularity and non-singularity vector field
Sensitive to noise Robust to noise
Ambiguity Avoids the ambiguity problem