Insert image in sphinx using napoleon pre-processor

Using sphinx 3.1.1, I want to insert an image using the napoleon pre-processor.

It seems that by having the command: ".. image::" in the docstring, it prevents pre-interpretation with the napoleon pre-processor and the docstring is interpreted by the standard sphinx interpreter.

"""Func

   Args:
       var1 (number): description 1.
       var2 (string): description 2.

   Returns:
       string: description 3.

.. image:: /_images/test.png
   :width: 100
"""

My image is correctly visualized, but parameters and return values are not correctly interpreted, they look like plain text.

When I remove the image command, I get the expected interpretation:

"""Func

   Args:
       var1 (number): description 1.
       var2 (string): description 2.

   Returns:
       string: description 3.
"""

Does anyone have a solution?

Remark: I don't want to write my documentation in sphinx standard reStructuredText.

Whitespace is important. The image directive must be aligned with the other paragraphs in the docstring.

It can look like this:

"""Func

   Args:
       var1 (number): description 1.
       var2 (string): description 2.

   Returns:
       string: description 3.

   .. image:: /_images/test.png
      :width: 100
"""

Or like this:

"""
Func
 
Args:
    var1 (number): description 1.
    var2 (string): description 2.
 
Returns:
    string: description 3.
 
.. image:: /_images/test.png
   :width: 100
"""