Merge branch 'docs-readthedocs-review' into 'master'

docs: readthedocs review

See merge request 3d/cars-park/cars!784

Author: dyoussef

AUTHORS.md

@@ -13,7 +13,7 @@ This file keeps track of authors contributions.
 ## Development Lead
 
 * David Youssefi <[email protected]>
-* Emmanuel Dubois <emmanuel.dubois@cnes.fr>
+* Valentine Bellet <valentine.bellet@cnes.fr>
 * Yoann Steux <[email protected]>
 * Mathis Roux <[email protected]>
 * Cedric Traizet <[email protected]>
@@ -22,6 +22,7 @@ This file keeps track of authors contributions.
 
 * Julien Michel <[email protected]>
 * Emmanuelle Sarrazin <[email protected]>
+* Emmanuel Dubois <[email protected]>
 * Aurélie Emilien <[email protected]>
 * Florian Douziech <[email protected]>
 * Loïc Dumas <[email protected]>

docs/source/exploring_the_field/from_satellite_images_to_dsm.rst

@@ -25,14 +25,29 @@ Generate a DSM step by step
    :target: index.html#rasterization
 
 .. |rasterization_circled| image:: ../images/dense.rasterization.circled.drawio.png
-	    
+
+.. |matching_spa| image:: ../images/sparse.matching.drawio.png
+   :target: index.html#matchingsparse
+
+.. |matching_spa_circled| image:: ../images/sparse.matching.circled.drawio.png
+
+.. |triangulation_spa| image:: ../images/sparse.triangulation.drawio.png
+   :target: index.html#triangulationsparse
+
+.. |triangulation_spa_circled| image:: ../images/sparse.triangulation.circled.drawio.png
+
+.. |rasterization_spa| image:: ../images/sparse.rasterization.drawio.png
+   :target: index.html#rasterizationsparse
+
+.. |rasterization_spa_circled| image:: ../images/sparse.rasterization.circled.drawio.png
+
 .. |resampling_image| image:: ../images/crop_image10.gif
 
-.. |matching_image| image:: ../images/crop_image13.png
+.. |matching_image| image:: ../images/crop_image13.drawio.png
 
 .. |matching_spa_image| image:: ../images/sift.png
 
-.. |triangulation_image| image:: ../images/point_cloud_as_image.png
+.. |triangulation_image| image:: ../images/point_cloud_as_image.drawio.png
 
 .. |triangulation_spa_image| image:: ../images/image27.png
 
@@ -109,12 +124,14 @@ To obtain a raster image, the final process projects each point into a 2D grid:
 +------------------------------+---------------------------------------------+
 
 Initial Input Digital Elevation Model
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+-------------------------------------
 
-For now, CARS can use an initial input Digital Elevation Model (:term:`DEM`) which is integrated in the stereo-rectification to minimize the disparity intervals to explore.
-Any geotiff file can be used.
+The user can provide as input a low resolution Digital Elevation Model (:term:`DEM`). It helps to minimize the disparity intervals to explore. Any geotiff file can be used.
+If the DEM is not specified by the user, an internal DEM is generated with sparse matches.
 
-The parameter is ``initial_elevation`` as seen in :ref:`configuration`.
+To download the low resolution DEM corresponding to your area, see section :ref:`download_srtm_tiles`.
+
+The parameter is ``dem`` in ``initial_elevation`` as seen in :ref:`configuration`.
 
 
 Altimetric exploration and geometric inaccuracies
@@ -123,3 +140,43 @@ Altimetric exploration and geometric inaccuracies
 To reduce the search interval (i.e. altimetric exploration) in the matching step and thus save computing time, a faster sparse matching step is typically used. This matching step also enables geometric errors to be corrected, thus ensuring that the epipolar geometry (based on these models) is correct.
 
 Matching can be performed with keypoints like `SIFT <https://www.cs.ubc.ca/~lowe/papers/ijcv04.pdf>`_.
+
+.. _matchingsparse:
+
++-----------------------------+---------------------------------------------+
+| Pipeline                    | Matching (sparse)                           |
++-----------------------------+---------------------------------------------+
+| |images_models|     |br|    | |matching_spa_image|                        |
+| |resampling|        |br|    |                                             |
+| |matching_spa_circled| |br| |                                             |
+| |triangulation_spa| |br|    |                                             |
+| |rasterization_spa| |br|    |                                             |
++-----------------------------+---------------------------------------------+
+
+The result is a sparse point cloud...
+
+.. _triangulationsparse:
+
++----------------------------------+---------------------------------------------+
+| Pipeline                         | Triangulation (sparse)                      |
++----------------------------------+---------------------------------------------+
+| |images_models|     |br|         | |triangulation_spa_image|                   |
+| |resampling|        |br|         |                                             |
+| |matching_spa|      |br|         |                                             |
+| |triangulation_spa_circled| |br| |                                             |
+| |rasterization_spa| |br|         |                                             |
++----------------------------------+---------------------------------------------+
+
+and a sparse digital surface model.
+
+.. _rasterizationsparse:
+
++----------------------------------+---------------------------------------------+
+| Pipeline                         | Rasterization (sparse)                      |
++----------------------------------+---------------------------------------------+
+| |images_models|     |br|         | |rasterization_spa_image|                   |
+| |resampling|        |br|         |                                             |
+| |matching_spa|      |br|         |                                             |
+| |triangulation_spa| |br|         |                                             |
+| |rasterization_spa_circled| |br| |                                             |
++----------------------------------+---------------------------------------------+

docs/source/exploring_the_field/masks_and_classifications_usage.rst

@@ -1,10 +1,11 @@
 Mask and Classification Usage
 =============================
 
-| Photogrammetry is a technique that cannot reproduce altitude on water. This technique also has difficulties for moving elements or in shaded areas.
+| Photogrammetry is a technique that cannot reproduce altitude on water. This technique also has difficulties for shaded areas, cloudy areas or moving elements such as cars.
 | For this reason, it is possible to mask out areas or apply ad hoc processing to aid the matching stage.
 
-Masks
+
+Mask
 -----
 
 | CARS can use a mask for each image in order to ignore some image regions (for instance water mask). This mask is taken into account during the whole 3D restitution process.

docs/source/howto.rst

@@ -10,11 +10,10 @@ Get full stereo products
 ========================
 
 
-Dinamis
--------
+Pléiades / SPOT 6-7 products (DINAMIS)
+--------------------------------------
 
-| DINAMIS is a platform that acquires and distributes satellite Earth imagery for french and foreign institutional users under `specific subscription conditions <https://dinamis.data-terra.org/en/eligible-users/>`_.
-| Please visit the dinamis website for more information: https://dinamis.data-terra.org/.
+| `DINAMIS <https://dinamis.data-terra.org/catalogue/>`_ is a platform that acquires and distributes satellite Earth imagery (Pléaides and Spot 6-7) for french and foreign institutional users under `specific subscription conditions <https://dinamis.data-terra.org/en/eligible-users/>`_.
 
 
 AIRBUS Pleiades NEO example files
@@ -68,17 +67,35 @@ Make input ROI images
      -bbx x1 y1 x2 y2   Bounding box from two points (x1, y1) and (x2, y2)
 
 		
+        
+How to find the coordinates of the bounding box ?
+.................................................
 
-For example, if you have downloaded the maxar example data :ref:`maxar_example_files`, you can choose a region of interest with `geojson.io <https://geojson.io/#map=16.43/-34.490433/-58.586864>`_.
+For example, if you have downloaded the maxar example data :ref:`maxar_example_files`, you are working in an area near to San Fernando in Argentina. Go to the website `geojson.io <https://geojson.io/>`_ in order to select your ROI:
 
-And then extract region, create config file and launch cars:
+.. |roisanfernando| image:: images/roi_san_fernando_argentina.jpg
+   :width: 60%
+
+|roisanfernando|
+
+You can either select the upper left corner with the lower right corner (in red in the previous image): 
 
 .. code-block:: console
 
-   cars-extractroi -il *.NTF -out ext_dir -bbx -58.5896 -34.4872 -58.5818 -34.4943
+   cars-extractroi -il *.NTF -out ext_dir -bbx -58.5809 -34.4934 -58.5942 -34.4869
    cars-starter -il ext_dir/*.tif -out out_dir > config.json
    cars config.json
 
+or the lower left corner with the upper right corner (in purple in the previous image):
+
+.. code-block:: console
+
+   cars-extractroi -il *.NTF -out ext_dir -bbx -58.5809 -34.4869 -58.5942 -34.4934
+   cars-starter -il ext_dir/*.tif -out out_dir > config.json
+   cars config.json
+
+
+N.B.: Instead of using ``cars-extractroi``, you can directly give the GeoJson dictionnary in the configuration file (Please, see :ref:`configuration` for details). In this case, the sparse steps (geometric corrections) are processed on the entire image and not only on the ROI. 
 
 Monitor tiles progression
 -------------------------
@@ -149,6 +166,8 @@ The low NDWI values can be considered as water area.
 .. code-block:: console
 
     gdal_calc.py -G input.tif --G_band=2 -N input.tif --N_band=4 --outfile=mask.tif --calc="((1.0*G-1.0*N)/(1.0*G+1.0*N))>0.3" --NoDataValue=0
+    
+It is also possible to produce a water mask with `SLURP <https://github.com/CNES/slurp>`_.   
 
 See next section to apply a gdal_translate to convert the mask with 1bit image struture.
 
@@ -168,7 +187,7 @@ To translate single image or multiband image with several nbits per band to 1bit
 Add band name / description in TIF files metadata
 --------------------------------------------------
 
-To add a band name / description in TIF files, for classification or color files in order to be used:
+To add a band name / description ("water", "cloud", etc.) in TIF files, for classification or color files in order to be used:
 
 
 .. code-block:: python
@@ -178,6 +197,49 @@ To add a band name / description in TIF files, for classification or color files
     band_in.SetDescription(band_description)
     data_in = None
 
+.. _download_srtm_tiles:
+
+Get low resolution DEM
+========================
+
+SRTM 90m DEM
+---------------
+
+It is possible to download a low resolution DEM (90-m SRTM) corresponding to your area. To get a SRTM tile, you need to run the following python script knowing the latitude and the longitude of your area:
+
+.. code-block:: python
+
+    import numpy as np
+
+    def get_srtm_tif_name(lat, lon):
+        """Download srtm tiles"""
+        # longitude: [1, 72] == [-180, +180]
+        tlon = (1+np.floor((lon+180)/5)) % 72
+        tlon = 72 if tlon == 0 else tlon
+
+        # latitude: [1, 24] == [60, -60]
+        tlat = 1+np.floor((60-lat)/5)
+        tlat = 24 if tlat == 25 else tlat
+
+        srtm = "https://srtm.csi.cgiar.org/wp-content/uploads/files/srtm_5x5/TIFF/srtm_%02d_%02d.zip" % (tlon, tlat)
+        return srtm
+
+    if __name__ == "__main__":
+        print("Get SRTM tile corresponding to latitude and longitude couple")
+        while 1:
+            print(">> Latitude? ", end="")
+            lat = input()
+            print(">> Longitude? ", end="")
+            lon = input()
+            print(">> SRTM filename:", get_srtm_tif_name(int(lat), int(lon)))
+            input()
+
+
+If your area intersects multiple latitudes and longitudes, get all the SRTM tiles and create a VRT from them:
+
+.. code-block:: console
+
+    gdalbuildvrt srtm.vrt srtm_tile1.tif srtm_tile2.tif
 
 Post process output
 ===================