message: doxygen: adjust IMAGE_PATH, allow custom OPENCV_DOCS_EXTRA_IMAGE_PATH
  add opencv/modules
  add opencv_contrib/modules
diff: @@ -130,9 +130,23 @@ if(DOXYGEN_FOUND)
  set(tutorial_js_path "${CMAKE_CURRENT_SOURCE_DIR}/js_tutorials")
  set(example_path "${CMAKE_SOURCE_DIR}/samples")
  + set(doxygen_image_path
  + ${CMAKE_CURRENT_SOURCE_DIR}/images
  + ${paths_doc}
  + ${tutorial_path}
  + ${tutorial_py_path}
  + ${tutorial_js_path}
  + ${paths_tutorial}
  + #${OpenCV_SOURCE_DIR}/samples/data # TODO: need to resolve ambiguous conflicts first
  + ${OpenCV_SOURCE_DIR}
  + ${OpenCV_SOURCE_DIR}/modules # <opencv>/modules
  + ${OPENCV_EXTRA_MODULES_PATH} # <opencv_contrib>/modules
  + ${OPENCV_DOCS_EXTRA_IMAGE_PATH} # custom variable for user modules
  + )
  +
  # set export variables
  string(REPLACE ";" " \\\n" CMAKE_DOXYGEN_INPUT_LIST "${rootfile} ; ${faqfile} ; ${paths_include} ; ${paths_hal_interface} ; ${paths_doc} ; ${tutorial_path} ; ${tutorial_py_path} ; ${tutorial_js_path} ; ${paths_tutorial} ; ${tutorial_contrib_root}")
  - string(REPLACE ";" " \\\n" CMAKE_DOXYGEN_IMAGE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/images ; ${paths_doc} ; ${tutorial_path} ; ${tutorial_py_path} ; ${tutorial_js_path} ; ${paths_tutorial}")
  + string(REPLACE ";" " \\\n" CMAKE_DOXYGEN_IMAGE_PATH "${doxygen_image_path}")
  string(REPLACE ";" " \\\n" CMAKE_DOXYGEN_EXCLUDE_LIST "${CMAKE_DOXYGEN_EXCLUDE_LIST}")
  string(REPLACE ";" " " CMAKE_DOXYGEN_ENABLED_SECTIONS "${CMAKE_DOXYGEN_ENABLED_SECTIONS}")
  # TODO: remove paths_doc from EXAMPLE_PATH after face module tutorials/samples moved to separate folders
  