Use of Image Mosaicing for Infrastructure Assessment · • UV mapping software as Unwrap3d in...
Transcript of Use of Image Mosaicing for Infrastructure Assessment · • UV mapping software as Unwrap3d in...
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Use of Image Mosaicing forInfrastructure Assessment
Juan Brugadasupervised by
Dr. Kenichi Soga, Prof. Roberto CipollaEngineering Department
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Bond Street C125 Shaft Inspection
• Bolted Cast Iron rings 6m and 4m diameter with concrete lining.
• Height: 20.5 m
• Photos taken at 28 levels within the shaft and at 9locations within each level
• Photos stitched using Autostitch and Serif Panorama software
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Example
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Stitched photos for each level
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Level 1 H=0.6m
Level 2 H=1.2m
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Level 3 H=1.8m
Level 4 H=2.6m
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Level 5 H=3.2m
Level 6 H=3.6m
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Level 7 H=4.1m
Level 8 H=4.6m
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Level 9 H=5.1m
Level 10 H=5.6m
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Level 11 H=6.1m
Level 12 H=6.6m
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Level 13 H=7.1m
Level 14 H=7.6m
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Level 15 H=8.1m
Level 16 H=8.9m
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Level 17 H=9.5m
Level 18 H=10m
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Level 19 H=11.3m
Level 20 H=12m
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Level 21 H=13.6m
Level 22 H=15m
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Level 23 H=16.4m
Level 24 H=17.8m
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Level 25 H=18.5m
Level 26 H=19.2m
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Level 27 H=20.2m
Level 28 H=20.5m
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Stitching different Levels
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Levels 21-24 (Stitched manually)
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Levels 4 to 10 (Serif Panorama)
Levels 11 to 14 (Autostitch)
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Levels 11 to 12 (Serif Panorama)
Levels 15 to 16 (Autostitch)
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Levels 23 to 24 (Autostitch)
Levels 22 to 24 (Serif Panorama)
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Combining Panoramas from different Levels
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Combined Panoramas Levels 4 to 10
Combined Panoramas Levels 11 to 12
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Combined Panoramas Levels 5 to 6
Combined Panoramas Levels 20 to 21
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Shepherd’s Bush DS-420B Shaft Inspection
• Bolted cast iron rings 6m diameter, tiled with secondary lining
• Height: 8.2 m
• Photos taken at 10 levels within the shaft and at 9locations within each level
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Level 1 H=0.32m
Level 2 H=1.9m
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Level 3 H=2.3m
Level 4 H=3.2m
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Level 5 H=4.6m
Level 6 H=5.1m
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Level 7 H=5.7m
Level 8 H=6.3m
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Level 9 H=6.9m
Level 10 H=7.5m
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Stitching different Levels
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Levels 1 to 5
Levels 5 to 8
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Levels 9 to 10
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The images can be used to create inspection charts
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Image visualization
Images can be visualized using:
• UV mapping software as Unwrap3d in which images are applied as texture to wireframe models
• Export to Quick Time or Real Player for cylindrical panorama visualiztion
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Images exported as Texture (Unwrap3d)
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Images exported as Texture (Unwrap3d)
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Images exported as Texture (Unwrap3d)
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Images exported to Quick Time
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Images exported to Quick Time
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Example of QTVR visualization in infrastructure monitoring
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Factors affecting the quality of the images
• Light intensity• Light direction• Focal Length of Lens• Object Distance• Aperture• Focus
• Digitizing rate• Field of View Balance• Exposure Time• Image Filtering• Working Distance• Lens Choice
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Factors affecting mosaicing
• Change of aperture/exposure time
• Vignetting (Intensity decreasing towards the edge of the image)
• Parallax effect due to unwanted motion of the optical centre
• Radial distortion
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Summary
• Photos of individual levels could be stitched due to good overlap between images
• Difficulty stitching vertically due to lack of overlap between photos at each level
• Combining panoramas from different levels is possible with adequate overlap of photos between levels
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Summary
• Image-mosaicing can be used to supplement inspection reports
• Useful for electronic incorporation of field data
• Further research into real-time mosaicing using video software
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Acknowledgements
The shaft inspection images shown in this presentation were provided by Mr. Christopher Chew and Mr. Kevin Roberts of Metronet