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La forge institutionnelle d'INRAE étant en production depuis le 10 juin 2025, nous vous invitons à y créer vos nouveaux projets.

  • Image Velocimetry
  • Fudaa Lspiv
  • Wiki
  • User manual
  • Image orthorectification

Image orthorectification · Changes

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Update Image orthorectification authored Nov 14, 2024 by Guillaume  Bodart's avatar Guillaume Bodart
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User-manual/Image-orthorectification.md
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...@@ -194,7 +194,7 @@ The coefficients $a_i$ have been calculated as presented in the previous section ...@@ -194,7 +194,7 @@ The coefficients $a_i$ have been calculated as presented in the previous section
The method for constructing orthoimages is as follows: The method for constructing orthoimages is as follows:
- Define the area to be imaged in the real-world coordinate system, that is, provide the (X,Y) coordinates of the 4 corners of the orthoimage (done in the [Orthorectification](User-Manual/Orthorectification-of-Images#transformation-parameters) menu). - Define the area to be imaged in the real-world coordinate system, that is, provide the (X,Y) coordinates of the 4 corners of the orthoimage (done in the [Orthorectification](User-Manual/Image-Orthorectification#transformation-parameters) menu).
- Sample this area with a given resolution to create a grid, where each node of this grid will be the center of a pixel in the orthorectified image. - Sample this area with a given resolution to create a grid, where each node of this grid will be the center of a pixel in the orthorectified image.
- For each grid node, with coordinates $(X_i,Y_i)$, calculate the corresponding coordinates in the source image $(i_i,j_i)$ using equation (2). The coordinates $(i_i,j_i)$ calculated this way are real numbers rather than integers. - For each grid node, with coordinates $(X_i,Y_i)$, calculate the corresponding coordinates in the source image $(i_i,j_i)$ using equation (2). The coordinates $(i_i,j_i)$ calculated this way are real numbers rather than integers.
- Assign to each pixel centered at $(X_i,Y_i)$ a grayscale intensity corresponding to the pixel $(i_i,j_i)$ in the source image. Since the coordinates $(i_i,j_i)$ are real numbers, interpolation on neighboring pixels is used to determine the grayscale intensity, with cubic convolution: - Assign to each pixel centered at $(X_i,Y_i)$ a grayscale intensity corresponding to the pixel $(i_i,j_i)$ in the source image. Since the coordinates $(i_i,j_i)$ are real numbers, interpolation on neighboring pixels is used to determine the grayscale intensity, with cubic convolution:
......
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Manuel utilisateur (français)

  1. Généralités
  2. Démarrer avec Fudaa-LSPIV
  3. Commencer une étude Fudaa-LSPIV
  4. Gestion des images sources
  5. Orthorectification des images
  6. Calcul de la vitesse de déplacement des traceurs
  7. Post traitement des vitesses calculées
  8. Affichage des résultats de vitesse
  9. Calcul du débit
  10. Export des données
  11. Relancer les calculs d'une étude existante
  12. Bug connus et parades
  13. Références bibliographiques

User manual (English)

  1. General information
  2. Getting started with Fudaa-LSPIV
  3. Starting a Fudaa-LSPIV study
  4. Managing source images
  5. Image orthorectification
  6. Tracers velocity computation
  7. Post-processing of velocity results
  8. Displaying velocity results
  9. Discharge computation
  10. Data export
  11. Relaunch existing study computations
  12. Known bugs and workarounds
  13. References