1. Barcelonnette 10/2013 STAGE INSTRUMENTAIRE MASTER 2 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO

2. WHAT? 2  Understand the basic principles of multi-view photogrammetry  Learn the steps involved in the processing workflow  Get to know and handle a wide range of software (Visual SFM, Meshlab,…)

3. WHY? 3  Estimation of mass-balances is crucial for the understanding of mass-wasting processes (landslides, erosion)  Distribution of surface fissures influences hydrological processes (infiltration and drainage) and signal underlying mechanical processes  Image-based methods are can be cost-efficient and fast complements to LiDAR acquisitions, traditional topographic surveys, and traditional mapping  Relatively new techniques that sill need development and long-term evaluation for geomorphological investigations

4. MULTIVIEW-STEREO - OVERVIEW 4 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO

5. STEP 1 – IMAGE ACQUISITION 5 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO

6. STEP 2 – FEATURE DETECTION 6 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO

7. STEP 3 – FEATURE MATCHING 7 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO -From pairwise matches a network (graph) of image matches is obtained

8. STEP 4 – SOLVE GEOMETRY (SFM) 8 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO STAGE INSTRUMENTAIRE MASTER II 10/2012 R… Rotation C… Translation F… Focal length X… Coordinates

9. STEP 4 – SOLVE GEOMETRY (SFM) 9 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO  Sparse point cloud and camera views

10. STEP 4 – SOLVE GEOMETRY (SFM) 10 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO

11. STEP 5 – DENSE MATCHING 11 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO  Patch-wise iteration of 3D point generation (computational intensive!)

12. STEP 5 – DENSE MATCHING 12 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO  Patch-wise iteration of 3D point generation (computational intensive!) Point-cloud Surface-mesh Textured model

13. FURTHER STEPS 13 3D SURFACE RECONSTRUCTION WITH MULTIVIEW-STEREO STAGE INSTRUMENTAIRE MASTER II 10/2012  Scaling and georeferencing  Comparison with LiDAR

14. THAT’S ALL FOLKS! PRACTICALS? Barcelonnette 10/2012