Table des matières
1. Theory, Preparation and Acquisition
- 1.1. Vertical imaging in archaeology: definitions
- 1.1.1. Nadir photography
- Definition
- Image distortion and geometric aberrations
- 1.1.2. Rectified photograph
- 1.1.3. Photogrammetry and orthophotography
- 1.2. Orthomosaic: the production process
- 1.2.1. Photo acquisition
- 1.2.2. Tie points (homologous points)
- 1.2.3. Camera calibration and orientation
- 1.2.4. Sparse point cloud
- 1.2.5. Geopositioning
- 1.2.6. Adjusting camera orientation and calibration
- 1.2.7. Densification
- 1.2.8. Orthorectification
- 1.2.9. Orthomosaic
- 1.3. Acquisition: choosing equipment/conducting the topographic survey
- 1.3.1. Photographic and topographic equipment
- Sensor
- Lens
- Camera body
- Remote acquisition
- Topography
- 1.3.2. Photography
- Regularity
- Sensitivity
- Aperture
- Shutter speed
- White balance
- File format
- Overlapping
- The number of photographs
- Calibration set (optional)
- Path and photo location
- Luminosity
- 1.3.3. Ground sample distance
- 1.3.4. Topography
- Installing ground control points
- Topographic survey settings
- Export
2. Process for Producing Plan Orthophotographs
- 2.1. Introducing MicMac
- 2.2. Preparing the directory
- 2.3. MicMac syntax
- 2.4. Processing
- 2.4.1. Searching for homologous/tie points
- Command
- Description
- Production
- 2.4.2. Verification of image alignment
- Command
- Description
- NB
- Production
- 2.4.3. Camera calibration
- Command
- Description
- NB
- Production
- Command to be run with a set of photos intended for calibration
- Description
- 2.4.4. Generating a sparse point cloud
- Command
- Description
- Production
- NB
- 2.4.5. Preparing the control points file
- 2.4.6. Transformation of the “topo” file
- Command
- Description
- Production
- 2.4.7. Data capture of GCPs
- Command
- Description
- NB
- Production
- 2.4.8. Geopositioning the model – coordinate reference system
- Command
- Description
- Production
- 2.4.9. Geopositioning the model – calculating and validating control points
- Command
- Description
- Production
- 2.4.10. Geopositioning the model – CRS precision
- Command
- Description
- Production
- 2.4.11. Geopositioning the model – final adjustment of camera orientation
- Command
- Description
- NB
- Production
- 2.4.12. Visualisation of the georeferenced homologous point cloud
- Command
- Description
- Production
- NB
- 2.4.13. Densification of the point cloud
- Command
- Description
- Production
- 2.4.14. Production of orthophotographs
- Command
- Description
- Production
- NB
- 2.4.15. Production of the orthomosaic
- Command
- Description
- Production
- NB
- 2.4.16. Assembling orthomosaic tiles (optional)
- Command
- Description
- Production
3. Process for Producing Elevation Orthophotographs: The Example of the Early Christian Church of Mirine
- 3.1. Introduction: the special relevance of MicMac for processing elevations
- 3.2. Experimental framework
- 3.3. Specific nature of acquisition for elevations
- Acquisition conditions
- Environmental constraints
- 3.4. Processing
- 3.4.1. Truncating point clouds before densifying oriented point clouds
- Command
- Description
- NB
- Production
- 3.4.2. Point cloud densification
- Command
- Description
- Production
- 3.4.3. Input of mask defining the orthophotograph plan
- Command
- Description
- NB
- 3.4.4. Calculating a temporary reference space
- Command
- Description
- Production
- 3.4.5. Producing the orthophotographs
- Command
- Description
- Production
- 3.4.6. If several point clouds are modelled at the same time (optional)
- Description
- NB
- 3.4.7. Producing the orthophotomosaic
- Command
- Description
- Production
- NB
- 3.4.8. Assembling orthophotomosaic tiles (optional)
- Command
- Description
- NB
- 3.5. Archaeological sections: a special case
- Command
- Description
- Production
- NB
