I initially created an issue here, but it seems it is the good place here:
System information (version) - OpenCV => 4.3.0 - Opencv_contrib => 4.3.0 - Operating System / Platform => Ubuntu 18.04 - Compiler => g++-8
Detailed description
Compilation errors occured when building OpenCV 4.3.0 with opencv_contrib 4.3.0. The problem is a conflict for type SIFT which is defined into two different namespaces. The code was built with the following options: -DWITH_OPENCL=ON -DWITH_V4L=ON -DOPENCV_EXTRA_MODULES_PATH=../../../src/OpenCV4/opencv_contrib/modules -DBUILD_EXAMPLES=ON
Note: I built it using catkin (from ROS) in a catkin isolated workspace as plain C-Make, so the same erros should occur without catkin build (which simply call make command for plain-cmake projects)
Errors occured when compiling generated files:
- modules/python_bindings_generator/pyopencv_generated_types_content.h
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:1904:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h: In function ‘PyObject* pyopencv_cv_xfeatures2d_xfeatures2d_SIFT_create_static(PyObject*, PyObject*, PyObject*)’:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h:74083:13: error: template argument 1 is invalid
Ptr<SIFT> retval;
^
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h:74093:56: error: invalid user-defined conversion from ‘cv::Ptr<cv::xfeatures2d::SIFT>’ to ‘int’ [-fpermissive]
ERRWRAP2(retval = cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:159:5: note: in definition of macro ‘ERRWRAP2’
expr; \
^~~~
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd.hpp:81,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/utils/configuration.private.hpp:8,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:35:
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: candidate is: ‘cv::Ptr<T>::operator T*() const [with T = cv::xfeatures2d::SIFT]’ <near match>
inline operator T* () const { return std::shared_ptr<T>::get(); }
^~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: no known conversion from ‘cv::xfeatures2d::SIFT*’ to ‘int’
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:1904:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h: In function ‘PyObject* pyopencv_cv_xfeatures2d_xfeatures2d_SIFT_create_static(PyObject*, PyObject*, PyObject*)’:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h:74083:13: error: template argument 1 is invalid
Ptr<SIFT> retval;
^
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h:74093:56: error: invalid user-defined conversion from ‘cv::Ptr<cv::xfeatures2d::SIFT>’ to ‘int’ [-fpermissive]
ERRWRAP2(retval = cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:159:5: note: in definition of macro ‘ERRWRAP2’
expr; \
^~~~
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd.hpp:81,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/utils/configuration.private.hpp:8,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:35:
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: candidate is: ‘cv::Ptr<T>::operator T*() const [with T = cv::xfeatures2d::SIFT]’ <near match>
inline operator T* () const { return std::shared_ptr<T>::get(); }
^~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: no known conversion from ‘cv::xfeatures2d::SIFT*’ to ‘int’
- modules/python_bindings_generator/pyopencv_generated_funcs.h:
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:1905:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h: In function ‘PyObject* pyopencv_cv_xfeatures2d_SIFT_create(PyObject*, PyObject*, PyObject*)’:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h:34421:13: error: template argument 1 is invalid
Ptr<SIFT> retval;
^
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h:34431:56: error: invalid user-defined conversion from ‘cv::Ptr<cv::xfeatures2d::SIFT>’ to ‘int’ [-fpermissive]
ERRWRAP2(retval = cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:159:5: note: in definition of macro ‘ERRWRAP2’
expr; \
^~~~
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd.hpp:81,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/utils/configuration.private.hpp:8,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:35:
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: candidate is: ‘cv::Ptr<T>::operator T*() const [with T = cv::xfeatures2d::SIFT]’ <near match>
inline operator T* () const { return std::shared_ptr<T>::get(); }
^~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: no known conversion from ‘cv::xfeatures2d::SIFT*’ to ‘int’
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:1905:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h: In function ‘PyObject* pyopencv_cv_xfeatures2d_SIFT_create(PyObject*, PyObject*, PyObject*)’:
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h:34421:13: error: template argument 1 is invalid
Ptr<SIFT> retval;
^
/home/gus/ressac/catkin_isolated_ws/build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h:34431:56: error: invalid user-defined conversion from ‘cv::Ptr<cv::xfeatures2d::SIFT>’ to ‘int’ [-fpermissive]
ERRWRAP2(retval = cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:159:5: note: in definition of macro ‘ERRWRAP2’
expr; \
^~~~
In file included from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd.hpp:81,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/utils/configuration.private.hpp:8,
from /home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/python/src2/cv2.cpp:35:
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: candidate is: ‘cv::Ptr<T>::operator T*() const [with T = cv::xfeatures2d::SIFT]’ <near match>
inline operator T* () const { return std::shared_ptr<T>::get(); }
^~~~~~~~
/home/gus/ressac/catkin_isolated_ws/src/OpenCV4/modules/core/include/opencv2/core/cvstd_wrapper.hpp:129:12: note: no known conversion from ‘cv::xfeatures2d::SIFT*’ to ‘int’
- Steps to reproduce
To reproduce this, build opencv 4.3.0 (from github) with opencv_contrib 4.3.0 (for github) with g++-8. => Errors are due to ambiguous types "SIFT" that are defines both in cv:: and cv::xfeatures2d:: namespaces.
To fix this I simply specify the namespace to use. See working patches below: - pyopencv_generated_funcs.h.patch :
--- ./build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_funcs.h 2020-06-11 09:47:42.958995206 +0200
+++ ./src/OpenCV4/patch/pyopencv_generated_funcs.h 2020-06-11 09:39:29.750997088 +0200
@@ -1945,7 +1945,7 @@
double edgeThreshold=10;
PyObject* pyobj_sigma = NULL;
double sigma=1.6;
- Ptr<SIFT> retval;
+ Ptr<cv::SIFT> retval;
const char* keywords[] = { "nfeatures", "nOctaveLayers", "contrastThreshold", "edgeThreshold", "sigma", NULL };
if( PyArg_ParseTupleAndKeywords(args, kw, "|OOOOO:SIFT_create", (char**)keywords, &pyobj_nfeatures, &pyobj_nOctaveLayers, &pyobj_contrastThreshold, &pyobj_edgeThreshold, &pyobj_sigma) &&
@@ -1955,7 +1955,7 @@
pyopencv_to(pyobj_edgeThreshold, edgeThreshold, ArgInfo("edgeThreshold", 0)) &&
pyopencv_to(pyobj_sigma, sigma, ArgInfo("sigma", 0)) )
{
- ERRWRAP2(retval = cv::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
+ ERRWRAP2(retval = (Ptr<cv::SIFT>)cv::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
return pyopencv_from(retval);
}
@@ -34399,7 +34399,7 @@
double edgeThreshold=10;
PyObject* pyobj_sigma = NULL;
double sigma=1.6;
- Ptr<SIFT> retval;
+ Ptr<cv::xfeatures2d::SIFT> retval;
const char* keywords[] = { "nfeatures", "nOctaveLayers", "contrastThreshold", "edgeThreshold", "sigma", NULL };
if( PyArg_ParseTupleAndKeywords(args, kw, "|OOOOO:SIFT_create", (char**)keywords, &pyobj_nfeatures, &pyobj_nOctaveLayers, &pyobj_contrastThreshold, &pyobj_edgeThreshold, &pyobj_sigma) &&
@@ -34409,7 +34409,7 @@
pyopencv_to(pyobj_edgeThreshold, edgeThreshold, ArgInfo("edgeThreshold", 0)) &&
pyopencv_to(pyobj_sigma, sigma, ArgInfo("sigma", 0)) )
{
- ERRWRAP2(retval = cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
+ ERRWRAP2(retval = (Ptr<cv::xfeatures2d::SIFT>)cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
return pyopencv_from(retval);
}
pyopencv_generated_types_content.h.patch :
--- ./build_isolated/OpenCV4/install/modules/python_bindings_generator/pyopencv_generated_types_content.h 2020-06-11 09:47:43.035995206 +0200 +++ ./src/OpenCV4/patch/pyopencv_generated_types_content.h 2020-06-11 09:39:17.403997135 +0200 @@ -15717,7 +15717,7 @@ double edgeThreshold=10; PyObject* pyobj_sigma = NULL; double sigma=1.6;
- Ptr<sift> retval;
Ptr<cv::sift> retval;
const char* keywords[] = { "nfeatures", "nOctaveLayers", "contrastThreshold", "edgeThreshold", "sigma", NULL }; if( PyArg_ParseTupleAndKeywords(args, kw, "|OOOOO:SIFT.create", (char**)keywords, &pyobj_nfeatures, &pyobj_nOctaveLayers, &pyobj_contrastThreshold, &pyobj_edgeThreshold, &pyobj_sigma) && @@ -15727,7 +15727,7 @@ pyopencv_to(pyobj_edgeThreshold, edgeThreshold, ArgInfo("edgeThreshold", 0)) && pyopencv_to(pyobj_sigma, sigma, ArgInfo("sigma", 0)) ) {
- ERRWRAP2(retval = cv::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
- ERRWRAP2(retval = (Ptr<cv::sift>)cv::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma)); return pyopencv_from(retval); }
@@ -72880,7 +72880,7 @@ double edgeThreshold=10; PyObject* pyobj_sigma = NULL; double sigma=1.6;
- Ptr<sift> retval;
Ptr<cv::xfeatures2d::sift> retval;
const char* keywords[] = { "nfeatures", "nOctaveLayers", "contrastThreshold", "edgeThreshold", "sigma", NULL }; if( PyArg_ParseTupleAndKeywords(args, kw, "|OOOOO:xfeatures2d_SIFT.create", (char**)keywords, &pyobj_nfeatures, &pyobj_nOctaveLayers, &pyobj_contrastThreshold, &pyobj_edgeThreshold, &pyobj_sigma) && @@ -72890,7 +72890,7 @@ pyopencv_to(pyobj_edgeThreshold, edgeThreshold, ArgInfo("edgeThreshold", 0)) && pyopencv_to(pyobj_sigma, sigma, ArgInfo("sigma", 0)) ) {
- ERRWRAP2(retval = cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma));
- ERRWRAP2(retval = (Ptr<cv::xfeatures2d::sift>)cv::xfeatures2d::SIFT::create(nfeatures, nOctaveLayers, contrastThreshold, edgeThreshold, sigma)); return pyopencv_from(retval); }
