Enhance cookbook extended filename section

Summary

Move and update the section about extended filename with examples.

Rationale

Extended filename is very interesting features of OTB and not only of OTB-Applications. Therefore put it in a dedicated file which can be extended with new examples seems for me a good idea.

Implementation Details

Classes and files

Add a ExtendedFilenames.rst file and remove this part from the OTB-Applications.rst file

Additional notes

It could be useful for users to have more examples.

Documentation/Cookbook/rst/ExtendedFilenames.rst

+.. _extended-filenames:
+
+Extended filenames
+================================
+
+Extended filenames is an interesting feature of OTB. With it, you can control
+several aspects of the beahvior of the OTB in the OTB-Applications or in our
+own C++ applications. Historically this feature has been desingn to solve
+an issue with how to handle geo-referencing information. 
+
+Indeed, there are multiple ways to define geo-referencing information. For
+instance, one can use a geographic transform, a cartographic projection,
+or a sensor model with RPC coefficients. A single image may contain
+several of these elements, such as in the “ortho-ready” products: this
+is a type of product still in sensor geometry (the sensor model is
+supplied with the image) but it also contains an approximative
+geographic transform that can be used to have a quick estimate of the
+image localisation. For instance, your product may contain a “.TIF” file
+for the image, along with a “.RPB” file that contains the sensor model
+coefficients and an “.IMD” file that contains a cartographic projection.
+
+This case leads to the following question: which geo-referencing
+element should be used when opening this image in OTB. In
+fact, it depends on the users need. For an orthorectification
+application, the sensor model must be used. In order to specify which
+information should be skipped, a syntax of extended filenames has been
+developed for both reading and writing.
+
+Since the development of this feature we have extend this mechanism for 
+other aspaects: like band or overview selection in reader part or support
+create option of gdal in writer part.The reader and writer extended filename 
+support is based on the same syntax, only the options are different. 
+To benefit from the extended file name mechanism, the following syntax 
+is to be used:
+
+::
+
+    Path/Image.ext?&key1=<value1>&key2=<value2>
+
+**Note that you’ll probably need to “quote” the filename, especially if calling
+applications from the bash command line.**
+
+Reader options
+^^^^^^^^^^^^^^
+
+::
+
+    &geom=<path/filename.geom>
+
+-  Contains the file name of a valid geom file
+
+-  Use the content of the specified geom file instead of
+   image-embedded geometric information
+
+-  empty by default, use the image-embedded information if available
+
+-----------------------------------------------
+
+::
+
+    &sdataidx=<(int)idx>
+
+-  Select the sub-dataset to read
+
+-  0 by default
+
+-----------------------------------------------
+
+::
+
+    &resol=<(int)resolution factor>
+
+-  Select the JPEG2000 sub-resolution image to read
+
+-  0 by default
+
+-----------------------------------------------
+
+::
+
+    &bands=r1,r2,...,rn
+
+-  Select a subset of bands from the input image
+
+-  The syntax is inspired by Python indexing syntax with
+   bands=r1,r2,r3,...,rn where each ri is a band range that can be :
+
+   -  a single index (1-based) :
+
+      -  :code:`2` means 2nd band
+
+      -  :code:`-1` means last band
+
+   -  or a range of bands :
+
+      -  :code:`3:` means 3rd band until the last one
+
+      -  :code:`:-2` means the first bands until the second to last
+
+      -  :code:`2:4` means bands 2,3 and 4
+
+-  empty by default (all bands are read from the input image)
+
+-----------------------------------------------
+
+::
+
+    &skipcarto=<(bool)true>
+
+-  Skip the cartographic information
+
+-  Clears the projectionref, set the origin to :math:`[0,0]` and the
+   spacing to :math:`[1/max(1,r),1/max(1,r)]` where :math:`r` is the resolution
+   factor.
+
+-  Keeps the keyword list
+
+-  false by default
+
+-----------------------------------------------
+
+::
+
+    &skipgeom=<(bool)true>
+
+-  Skip geometric information
+
+-  Clears the keyword list
+
+-  Keeps the projectionref and the origin/spacing information
+
+-  false by default.
+
+-----------------------------------------------
+
+::
+
+    &skiprpctag=<(bool)true>
+
+-  Skip the reading of internal RPC tags (see
+   [sec:TypesofSensorModels] for details)
+
+-  false by default.
+
+Writer options
+^^^^^^^^^^^^^^
+
+::
+
+    &writegeom=<(bool)false>
+
+-  To activate writing of external geom file
+
+-  true by default
+
+-----------------------------------------------
+
+::
+
+    &writerpctags=<(bool)true>
+
+-  To activate writing of RPC tags in TIFF files
+
+-  false by default
+
+-----------------------------------------------
+
+::
+
+    &gdal:co:<GDALKEY>=<VALUE>
+
+-  To specify a gdal creation option
+
+-  For gdal creation option information, see dedicated gdal documentation for each driver. For example, you can find `here <http://www.gdal.org/frmt_gtiff.html>`_ the information about the GeoTiff create options
+
+-  None by default
+
+-----------------------------------------------
+
+::
+
+    &streaming:type=<VALUE>
+
+-  Activates configuration of streaming through extended filenames
+
+-  Override any previous configuration of streaming
+
+-  Allows to configure the kind of streaming to perform
+
+-  Available values are:
+
+   -  auto: tiled or stripped streaming mode chosen automatically
+      depending on TileHint read from input files
+
+   -  tiled: tiled streaming mode
+
+   -  stripped: stripped streaming mode
+
+   -  none: explicitly deactivate streaming
+
+-  Not set by default
+
+-----------------------------------------------
+
+::
+
+    &streaming:sizemode=<VALUE>
+
+-  Allows to choose how the size of the streaming pieces is computed
+
+-  Available values are:
+
+   -  auto: size is estimated from the available memory setting by
+      evaluating pipeline memory print
+
+   -  height: size is set by setting height of strips or tiles
+
+   -  nbsplits: size is computed from a given number of splits
+
+-  Default is auto
+
+-----------------------------------------------
+
+::
+
+    &streaming:sizevalue=<VALUE>
+
+-  Parameter for size of streaming pieces computation
+
+-  Value is :
+
+   -  if sizemode=auto: available memory in Mb
+
+   -  if sizemode=height: height of the strip or tile in pixels
+
+   -  if sizemode=nbsplits: number of requested splits for streaming
+
+-  If not provided, the default value is set to 0 and result in
+   different behaviour depending on sizemode (if set to height or
+   nbsplits, streaming is deactivated, if set to auto, value is
+   fetched from configuration or cmake configuration file)
+
+-----------------------------------------------
+
+::
+
+    &box=<startx>:<starty>:<sizex>:<sizey>
+
+-  User defined parameters of output image region
+
+-  The region must be set with 4 unsigned integers (the separator
+   used is the colon ’:’). Values are:
+
+   -  startx: first index on X (starting with 0)
+
+   -  starty: first index on Y (starting with 0)
+
+   -  sizex: size along X
+
+   -  sizey: size along Y
+
+-  The definition of the region follows the same convention as
+   itk::Region definition in C++. A region is defined by two classes:
+   the itk::Index and itk::Size classes. The origin of the region
+   within the image with which it is associated is defined by Index
+
+-----------------------------------------------
+
+::
+
+    &bands=r1,r2,...,rn
+
+-  Select a subset of bands from the output image
+
+-  The syntax is inspired by Python indexing syntax with
+   bands=r1,r2,r3,...,rn where each ri is a band range that can be :
+
+   -  a single index (1-based) :
+
+      -  :code:`2` means 2nd band
+
+      -  :code:`-1` means last band
+
+   -  or a range of bands :
+
+      -  :code:`3:` means 3rd band until the last one
+
+      -  :code:`:-2` means the first bands until the second to last
+
+      -  :code:`2:4` means bands 2,3 and 4
+
+-  Empty by default (all bands are write from the output image)
+
+The available syntax for boolean options are:
+
+-  ON, On, on, true, True, 1 are available for setting a ’true’ boolean
+   value
+
+-  OFF, Off, off, false, False, 0 are available for setting a ’false’
+   boolean value
+   
+Examples
+^^^^^^^^^^^^^^
+
+You can find below some examples:
+
+- Write a file with blockSize equal to 256 and with DEFLATE compression
+
+::
+
+    $ otbcli_Convert -in OTB-Data/Examples/QB_1_ortho.tif -out "/tmp/example1.tif?&gdal:co:TILED=YES&gdal:co:COMPRESS=DEFLATE"
+
+- Process only first band from a file
+
+::
+
+    $ otbcli_Convert -in "OTB-Data/Examples/QB_1_ortho.tif?&bands=1" -out /tmp/example2.tif