Oct CIPA Congress, Athens- Low cost photogrammetric systems COST-EFFECTIVE ROCK-ART RECORDING IN A PRODUCTION ENVIRONMENT: IS THERE A WIDER MESSAGE? Jim Chandler, Loughborough University, UK Paul Bryan, English Heritage, UK

Oct CIPA Congress, Athens- Low cost photogrammetric systems CIPA 2005, Torino Paper: “ Paper: “RECORDING ABORIGINAL ROCK ART USING CHEAP DIGITAL CAMERAS AND DIGITAL PHOTOGRAMMETRY” Method applied to record 1500 rock art motifs in UK Method applied to record 1500 rock art motifs in UK

Oct CIPA Congress, Athens- Low cost photogrammetric systems Presentation structure Review method- briefly Review method- briefly Application in a production environment, using volunteers! Application in a production environment, using volunteers! Lessons learnt Lessons learnt Concluding remarks/message Concluding remarks/message

Oct CIPA Congress, Athens- Low cost photogrammetric systems Method- fieldwork Cheap digital cameras Simple image acquisition Simple control: ScalebarTargets

Oct CIPA Congress, Athens- Low cost photogrammetric systems Method- processing Simple/commercial software Simple/commercial software Leica photogrammetry system (LPS) Leica photogrammetry system (LPS) Cost- $20K (USD) Cost- $20K (USD)

Oct CIPA Congress, Athens- Low cost photogrammetric systems Method- Outputs Digital Elevation Models (DEMs) Digital Elevation Models (DEMs) Accuracies- 2-3mm Accuracies- 2-3mm Orthophotos Orthophotos Visualisation “fly- thru” fly- thrufly- thru

Oct CIPA Congress, Athens- Low cost photogrammetric systems Northumberland and Durham Regional Rock Art 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 CIPA Congress, Athens- Low cost photogrammetric systems Superb results! 3D Laser scanning? Image courtesy of Tertia Barnett BUT problems with: shading, expertise, expense and portability!

Oct CIPA Congress, Athens- Low cost photogrammetric systems The way forward?  60 volunteer workers identified  Equip with cheap digital cameras!?  Train for photogrammetric image capture  Measurement?

Oct CIPA Congress, Athens- Low cost photogrammetric systems Camera calibration Calibrated at 1.5m distance: 2x in July July Stable over 1 year period Also, consistency in manufacture! Wackrow, R., Chandler, JH, Bryan, P 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 CIPA Congress, Athens- Low cost photogrammetric systems Training Workshop, April 2005 Simple stereo/flexible data acquisition Basic control Basic photogrammetry Further guidance Telephone/ support Direct field support

Oct CIPA Congress, Athens- Low cost photogrammetric systems Early experience Enthusiasm! Enthusiasm! Even or raking light? Even or raking light? Topcon PI 3000 software Topcon PI 3000 software Just image capture or full data acquisition? Just image capture or full data acquisition?

Oct CIPA Congress, Athens- Low cost photogrammetric systems Further refinement Larger panels Larger panels Routine measurement BY VOLUNTEERS! Routine measurement BY VOLUNTEERS! DEMs 2mm and 10mm point spacing (DXF) DEMs 2mm and 10mm point spacing (DXF) orthophotographs (JPEG) and virtual modelling (VRML) orthophotographs (JPEG) and virtual modelling (VRML) 95% of panels measured BY VOLUNTEERS! 95% of panels measured BY VOLUNTEERS! Image acquisition and training of volunteers (courtesy: Tertia Barnett)

Oct CIPA Congress, Athens- Low cost photogrammetric systems Archiving via ADS (Archaeology Data Service) Archiving strategy includes dissemination of acquired data-sets Archiving strategy includes dissemination of acquired data-sets Includes raw-stereo- photography and processed data: Includes raw-stereo- photography and processed data: VRML + DXF VRML + DXF PI-3000 project files PI-3000 project files Original imagery Original imagery

Oct CIPA Congress, Athens- Low cost photogrammetric systems Lessons learnt Technology and the volunteer. video Technology and the volunteer. video video Don’t underestimate Don’t underestimate Added political benefits! Added political benefits! Hi tech or low? Hi tech or low?

Oct CIPA Congress, Athens- Low cost photogrammetric systems Conclusion Low cost, consumer-grade digital cameras can play an important role in heritage recording Low cost, consumer-grade digital cameras can play an important role in heritage recording Low cost/simplified fieldwork- volunteers, many advantages! Low cost/simplified fieldwork- volunteers, many advantages! More emphasis on low cost/simple solutions? More emphasis on low cost/simple solutions?Publications: Rock Art Research- journal paper, Nov 2005 Rock Art Research- journal paper, Nov 2005 CIPA conference papers, Torino/Athens- Sept. 2005, Oct CIPA conference papers, Torino/Athens- Sept. 2005, Oct Photogrammetric Record- journal paper, March 2007 Photogrammetric Record- journal paper, March 2007 “Applications of 3D measurement from Images”, Book- Sept “Applications of 3D measurement from Images”, Book- Sept