Embed Size (px)
DESCRIPTION
COST-EFFECTIVE ROCK-ART RECORDING IN A PRODUCTION ENVIRONMENT: IS THERE A WIDER MESSAGE?. Jim Chandler, Loughborough University, UK Paul Bryan, English Heritage, UK. CIPA 2005, Torino. Paper: “ RECORDING ABORIGINAL ROCK ART USING CHEAP DIGITAL CAMERAS AND DIGITAL PHOTOGRAMMETRY” - PowerPoint PPT Presentation
Citation preview
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
COST-EFFECTIVE ROCK-ART COST-EFFECTIVE ROCK-ART RECORDING IN A PRODUCTION RECORDING IN A PRODUCTION
ENVIRONMENT: IS THERE A WIDER ENVIRONMENT: IS THERE A WIDER
MESSAGE?MESSAGE? Jim Chandler, Loughborough Jim Chandler, Loughborough
University, UKUniversity, UK
Paul Bryan, English Heritage, UKPaul Bryan, English Heritage, UK
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
CIPA 2005, TorinoCIPA 2005, Torino
Paper: Paper: ““RECORDING ABORIGINAL ROCK ART USING CHEAP DIGITAL CAMERAS AND DIGITAL PHOTOGRAMMETRY”
Method applied to Method applied to record record 15001500 rock rock art motifs in UKart motifs in UK
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Presentation structurePresentation structure Review method- brieflyReview method- briefly Application in a production Application in a production
environment, using volunteers!environment, using volunteers! Lessons learntLessons learnt Concluding remarks/messageConcluding remarks/message
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Method- fieldworkMethod- fieldwork
Cheap digital Cheap digital camerascameras
Simple image Simple image acquisitionacquisition
Simple control:Simple control:ScalebarScalebarTargetsTargets
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Method- processingMethod- processing Simple/commercial Simple/commercial
softwaresoftware Leica Leica
photogrammetry photogrammetry system (LPS)system (LPS)
Cost- $20K (USD)Cost- $20K (USD)
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Method- OutputsMethod- Outputs
Digital Elevation Digital Elevation Models (DEMs)Models (DEMs)
Accuracies- 2-Accuracies- 2-3mm3mm
OrthophotosOrthophotos
Visualisation “Visualisation “fly-thru”
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Northumberland and Durham Regional Rock Northumberland and Durham Regional Rock Art projectArt project
• Pilot project originally launched in 2004
• Partnership between English Heritage and the County Councils for Northumberland and Durham
• Loughborough University advising on the photogrammetry
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Superb results!Superb results!
3D Laser scanning?
Image courtesy of Tertia Barnett
BUT problems BUT problems with: shading, with: shading, expertise, expertise, expense and expense and portability!portability!
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
The way The way forward?forward?
60 volunteer workers identified
Equip with cheap digital cameras!?
Train for photogrammetric image capture
Measurement?
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Camera calibrationCamera calibration Calibrated at 1.5m distance: 2x in July 2005 +
July 2006. Stable over 1 year period
Also, consistency in manufacture!Wackrow, R., Chandler, JH, Bryan, P. 2007. Geometric consistency and
stability of consumer-grade digital cameras for accurate spatial measurement. The Photogrammetric Record 22 (118): 121–134.
Radial distortion differences with respect to a mean curve for all cameras
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
TrainingTraining
Workshop, April 2005 Simple stereo/flexible
data acquisition Basic control Basic photogrammetry
3x3 principles: 3 geometrical rules3x3 principles: 3 geometrical rules
ControlControl PhotoPhoto--acquisitionacquisition
•• Acquire as Acquire as ““pairspairs””•• Base/distance Base/distance
ratio ratio 1:61:6
•• ““NormalNormal””photography?photography?
Further guidanceTelephone/email supportDirect field support
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Early experienceEarly experience
Enthusiasm! Enthusiasm! Even or raking Even or raking
light? light? Topcon PI 3000 Topcon PI 3000
softwaresoftware Just image capture Just image capture
or full data or full data acquisition?acquisition?
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Further refinementFurther refinement
Larger panelsLarger panels Routine Routine
measurement BY measurement BY VOLUNTEERS!VOLUNTEERS! DEMs 2mm and 10mm DEMs 2mm and 10mm
point spacing (DXF)point spacing (DXF) orthophotographs (JPEG) orthophotographs (JPEG)
and virtual modelling and virtual modelling (VRML)(VRML)
95% 95% of panels measured of panels measured
BY VOLUNTEERS!BY VOLUNTEERS!
Image acquisition and training of volunteers (courtesy: Tertia Barnett)
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Archiving via ADS (Archaeology Data Service)
Archiving strategy Archiving strategy includes includes dissemination of dissemination of acquired data-setsacquired data-sets
Includes raw-Includes raw-stereo-photography stereo-photography and processed data:and processed data: VRML + DXFVRML + DXF PI-3000 project filesPI-3000 project files Original imageryOriginal imagery
http://ads.ahds.ac.uk/
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
Lessons learntLessons learnt
Technology and Technology and the volunteer. the volunteer. videovideo
Don’t Don’t underestimate underestimate
Added political Added political benefits!benefits!
Hi tech or low?Hi tech or low?
Oct. 2007 CIPA Congress, Athens- Low cost photogrammetric systems
ConclusionConclusion Low cost, consumer-grade digital cameras Low cost, consumer-grade digital cameras
can play an important role in heritage can play an important role in heritage recording recording
Low cost/simplified fieldwork- volunteers, Low cost/simplified fieldwork- volunteers, many advantages!many advantages!
More emphasis on low cost/simple More emphasis on low cost/simple solutions?solutions?
Publications:Publications: Rock Art Research- journal paper, Nov 2005Rock Art Research- journal paper, Nov 2005 CIPA conference papers, Torino/Athens- Sept. 2005, Oct 2007.CIPA conference papers, Torino/Athens- Sept. 2005, Oct 2007. Photogrammetric Record- journal paper, March 2007Photogrammetric Record- journal paper, March 2007 ““Applications of 3D measurement from Images”, Book- Sept. Applications of 3D measurement from Images”, Book- Sept.
20072007 [email protected]://www-staff.lboro.ac.uk/~cvjhc
