Laconic Shape Descriptors

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Laconic Shape Descriptors
laconic adj concise, curt, short, succinct

• Michael BurnsCOS 597D
• November 20, 2003

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Premise
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• Premise Given a class of objects, statistical
  data derived from the class can help traditional
  geometric algorithms

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Motivation
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• Shape matching compares shape descriptors
• GEDT, radial extent, etc
• Matching between many models is expensive

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Motivation
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• Newly acquired models need to be classified
• Brute force method requires n comparisons over n
  models

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Solution Laconic Shape Descriptors (LSD)
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• Calculate average shape descriptor for the class
• Use this descriptor to facilitate fast
  classification
• Average of shape descriptors over a class of
  objects should contain characteristic information
  about class

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How good is LSD?
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• Shape descriptors are consistent within class
• LSD should be representative

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How good is LSD?
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• Shape descriptors are different between classes
• LSD should be discriminating

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LSD is easy to find
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• Using Voxel representation
• Align model
• Voxelize model
• Apply Gaussian Euclidean Distance Transformation
• Merge (average) transformed voxels over a class

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Benefits of LSD
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• LSD means speed (in classification)
• LSD may generate interesting visuals

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Acknowledgements
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• Tom, Misha, eventually everyone