3D Scanning for museums

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3D Scanning for museums

• Kirk Martinez
• University of Southampton

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Overview
Why? Techniques available Laser image-based Su
mmary
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Motivation
2d representations dont capture 3D objects
well Any 2-D view can be generated from a single
3-D model. 3D studies can be done models can be
compared/searched
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Examples of scanners
Cyberware
Digibotics
3dscanners
Polhemus
Mensi
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Structured light scanning

• example from CNR Italy

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Michelangelo project

• by Stanford
• used Cyberware

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Arius 3D

• laser based developed by CNR Canada
• RGB lasers give colour

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Issues

• Some objects can be very large e.g. building
• Objects can be very complex e.g. lots of holes
• Lighting conditions often very important
• File formats and browsers
• Cost

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Image-based 3D reconstruction techniques

• Image sequences of rotating objects
• Two approaches used
• Silhouette-based only approach CANON software
• Silhouette and multi-stereo technique GET-ENST
  approach
• For less complex objects with textured surface
• Required
• good quality image sequences (precise turntable,
  good lighting, photographic know-how)
• good silhouette segmentation

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Turntable approach

• ENST scanner

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VA dual-cameras

• saves camera setup
• faster

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3D laser acquisition reconstruction

• Using MINOLTA Vi 900 laser scanner (ARCHIDATA)
• Using reconstruction software
• Rapidform (C2RMF, Cherbourg)
• Maya (Quai Branly)
• User partners involved
• White clay Gallo-Roman figurines and moulds
• C2RMF - Bourbon-Lancy
• C2RMF - Moulins
• Miscellaneous
• C2RMF - Cluny
• Cherbourg
• Quai Branly (external partner, negotiation for
  collaboration in progress)

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Outdoor scanning example

• Coloseum in Rome with Minolta laser scanner

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3D Laser Cherbourg
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Image-based 3D reconstruction VAM
33 objects statuettes, ceramic French vases
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GET-ENST silhouette and multi-stereo technique
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Image-based 3D
3D
Image acquisition
Camera calibration
3D Reconstruction
Texture map creation
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Results
57639 sommets, 115282 triangles
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Results compared with laser
Scanner laser 3D Minolta
Methode proposée
385355 sommets770209 triangles
233262 sommets466520 triangles
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Results
47159 vertices, 94322 triangles
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Image-based 3D reconstruction GET-ENST Examples
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Summary

• Cost / quality / time trade-offs
• Techniques vary in
• mesh quality
• texturing quality
• some scanners are better suited to some materials
• smaller 3D models are simple to put on Web