Gravillons tutorial : Différence entre versions
(→2 Internal Orientation+Relative Orientation) |
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==Tutorial== | ==Tutorial== | ||
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===1 Tie-Points research=== | ===1 Tie-Points research=== | ||
The first step of each MicMac uses is to determine images which are looking at the same scene, this step is call image matching and performed by the command Tapioca : | The first step of each MicMac uses is to determine images which are looking at the same scene, this step is call image matching and performed by the command Tapioca : | ||
<pre>mm3d Tapioca MulScale ".*.JPG" 500 1500</pre> | <pre>mm3d Tapioca MulScale ".*.JPG" 500 1500</pre> | ||
The MulScale option is generally faster, because it match images at high resolution (1500px here) only between images which are matching at low resolution (500px here). | The MulScale option is generally faster, because it match images at high resolution (1500px here) only between images which are matching at low resolution (500px here). | ||
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===2 Internal Orientation+Relative Orientation=== | ===2 Internal Orientation+Relative Orientation=== | ||
Photogrammetry is composed of three steps : | Photogrammetry is composed of three steps : | ||
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<pre>mm3d Tapas FraserBasic ".*.JPG" Out=Arbitrary</pre> | <pre>mm3d Tapas FraserBasic ".*.JPG" Out=Arbitrary</pre> | ||
This tools use a compensation by least squares to determine camera's parameter and relative orientation. The option "FraserBasic", correspond to a model of disorsion for our camera. The "option" Out specify the name of the orientation directory. | This tools use a compensation by least squares to determine camera's parameter and relative orientation. The option "FraserBasic", correspond to a model of disorsion for our camera. The "option" Out specify the name of the orientation directory. | ||
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| + | ===3 Visualize Relative Orientation=== | ||
| + | MicMac include a tools which create a sparse point cloud (TPs) for visualization. This tool is AperiCloud : | ||
| + | <pre>mm3d AperiCloud ".*.JPG" Arbitrary</pre> | ||
| + | After this step, a ".ply" file will appear in your working directory, open it with Meshlab (see Useful softwares for MicMac #Link#) | ||
Version du 3 février 2016 à 18:55
Sommaire
Download
You can found this dataset at :http://logiciels.ign.fr/?Telechargement,20
Datasets are available at the bottom of the page, in part test datasets. Then, UnZip the ".zip" archive.
Presentation
This dataset was created by L.Girod in Norway. This dataset was acquired to modelise a volcanoes model realised by O.Galland. File present in the directory are :
- 4 images : 1.JPG, 2.JPG, 3.JPG, 4.JPG.
- GCPs coordinates : Dico-Appuis.xml.
- Mesure of GCPs in images : Mesure-Appuis.xml.
- 1 Mask : 1_Masq.tif/1_Masq.xml
- 2 scripts de commandes : gravillons.sh (Linux) et gravillons.bat (Windows)
During this tutorial, we will approach general concepts, for more details, go further in tutorials or directly in commands pages.
Tutorial
1 Tie-Points research
The first step of each MicMac uses is to determine images which are looking at the same scene, this step is call image matching and performed by the command Tapioca :
mm3d Tapioca MulScale ".*.JPG" 500 1500
The MulScale option is generally faster, because it match images at high resolution (1500px here) only between images which are matching at low resolution (500px here).
2 Internal Orientation+Relative Orientation
Photogrammetry is composed of three steps :
- Internal Orientation : which consist to determine camera's paremeter (focal length, PPA, PPS, distorsion center, or distorsion parameters).
- Relative Orientation : which consist to determine position of each camera's from each other in an arbitrary system.
- Absolute Orientation : which consist to bascule the relative orientation to a scaled and oriented system (typically WGS84)
In digital photogrammetry, the two first steps are generally processed at the same time. In MicMac, the tools which perform internal and relative orientation is call Tapas :
mm3d Tapas FraserBasic ".*.JPG" Out=Arbitrary
This tools use a compensation by least squares to determine camera's parameter and relative orientation. The option "FraserBasic", correspond to a model of disorsion for our camera. The "option" Out specify the name of the orientation directory.
3 Visualize Relative Orientation
MicMac include a tools which create a sparse point cloud (TPs) for visualization. This tool is AperiCloud :
mm3d AperiCloud ".*.JPG" Arbitrary
After this step, a ".ply" file will appear in your working directory, open it with Meshlab (see Useful softwares for MicMac #Link#)
