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Dr.-Ing. Sung Joon Ahn

CurvSurf, Inc.

Some Thoughts on 2-D/3-D Information Processing

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Information 2-D Camera 3-D Camera 3-D CT-Scanner

Primary Pixel Surfel Voxel

Secondary Edgel Surface Surfel

Tertiary 2-D Curve 3-D Curve Surface

Quaternary 2-D Point 3-D Point 3-D Curve

Quinary -- -- 3-D Point

2-D/3-D Information Unit

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Description 2-D Camera 3-D CT-Scanner

Sensor raw data Pixel Voxel

Boundary point of regions Edgel Surfel

Mathematical

representation 2-D Curve Surface

Intersection 2-D Point 3-D Curve

Corner -- 3-D Point

2-D/3-D Information Description

* With 3-D Camera:

Sensor raw data ( = point cloud, surfels ) = Boundary points of 3-D volumes.

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• Pixels are the sensor raw data.

• Edgels are boundary points of regions

and are unstable information.

• Edgels do not much provide information

on regions.

• 2-D curves fitted to edgels represent

mathematically the boundary of regions.

They are relatively stable information

because of average-effect.

• Position, rotation, size, corner, etc. can

be deduced from the 2-D curves fitted.

2-D Information Processing

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• Point cloud (surfels) is the sensor raw data.

• Surfels are boundary points of volumes

and are unstable information.

• Surfels do not much provide information

on volumes.

• Surfaces fitted to surfels represent

mathematically the boundary of volumes.

They are relatively stable information

because of average-effect.

• Position, rotation, size, edge, corner, etc.

can be deduced from the surfaces fitted.

3-D Information Processing (1)

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• Some people are trying to extract more

unstable edgels from unstable point cloud,

ignoring the richness of point cloud.

• Much better is to fit stable surfaces to

unstable point cloud and deduce

more stable information of position,

rotation, size, etc. from the surfaces fitted.

3-D Information Processing (2)

+ + =

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• Further discussions are welcomed

• https://plus.google.com/+CurvSurf

Closing

Thank you!