ImportError when trying to load otb (orfeo-toolbox) into QGIS Python Console

Question

I would like to use the orfeo-toolbox via the QGIS Python Console, however, I don't seem to be able to import the otbApplication. I keep getting the following error:

import otbApplication
Traceback (most recent call last):
  File "C:\OTB\lib\python3\otbApplication.py", line 14, in swig_import_helper
    return importlib.import_module(mname)
  File "C:\OSGEO4~1\apps\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 670, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 583, in module_from_spec
  File "<frozen importlib._bootstrap_external>", line 1043, in create_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
ImportError: DLL load failed: The specified module could not be found.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\OSGEO4~1\apps\Python37\lib\code.py", line 90, in runcode
    exec(code, self.locals)
  File "<input>", line 1, in <module>
  File "C:/OSGEO4~1/apps/qgis/./python\qgis\utils.py", line 737, in _import
    mod = _builtin_import(name, globals, locals, fromlist, level)
  File "C:\OTB\lib\python3\otbApplication.py", line 17, in <module>
    _otbApplication = swig_import_helper()
  File "C:\OTB\lib\python3\otbApplication.py", line 16, in swig_import_helper
    return importlib.import_module('_otbApplication')
  File "C:\OSGEO4~1\apps\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ImportError: DLL load failed: The specified module could not be found.

I am using a Windows 10 computer and QGIS 3.8.2. I downloaded OTB 6.6.1, cloned the qgis-otb-plugin, and configured the environment variables as described in the Orfeo Toolbox Cookbook and various other resources.

I can use the OTB tools in the QGIS GUI, but not import it into the QGIS Python Console.

Answer 1

OTB python bindings are prebuilt for a specific version of python3 which I think is bit older than python3.x used in OSGeo4W

Possible workarounds: (order of increasing difficulty)

• Check if OSGeo4W can use same python version OTB uses in its built. If so, reinstall qgis with that python version.

• Install python version used by OTB and call "import otbApplication" in that python's console. (python is fairly easy to install on windows)

• Rebuild only python bindings using OTB windows package using OSGeo4W python libs (requires compiler, swig etc...)

• Raise issue on gitlab and if otb team make a priority issue, then you can wait for MR and grab the next days binary package (no wait for release)

• Wait for otb to find and make this issue priority themselves . (less likely to happen)

OTB works in QGIS GUI is not a surprise because I specifically taken care to not use python bindings of OTB in OTB QGIS Provider.