SfM (Structure from Motion)
Definition
A photogrammetric method that builds a 3D point cloud and orthomosaic from overlapping images by computing camera positions and feature matches. Standard processing pipeline for UAV survey data.
- Inputs
- Overlapping photographs
- Outputs
- 3D point cloud and orthomosaic
- Method
- Computed camera positions and feature matches
- Common platform
- UAV survey data processing
Common questions
How does SfM determine camera position without GPS on every image?+
It matches shared visual features across overlapping photographs and triangulates their relative geometry, computationally recovering each camera's position and orientation, though ground control points or onboard GPS improve absolute accuracy.
What makes image overlap important for a reliable SfM result?+
Insufficient overlap between consecutive photographs leaves gaps where the algorithm cannot match enough shared features, producing holes or distortions in the resulting point cloud and orthomosaic.
Related terms
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- Orthomosaic
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- UNOSAT
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