How to compile OpenCV with Boost::Python? - c++

Question

I'm trying to compile OpenCV in C++ with boost::python but I keep getting a linker error that I can't quite resolve.
Here is the code below.
cascade_handler.cpp
#include <iostream>
#include <boost/python.hpp>
#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/ocl/ocl.hpp>
#include "cascade_handler.h"
using namespace std;
using namespace boost::python;
void CascadeHandler::cascade_classifier_cpu(const string *cascade_file, std::vector<cv::Rect>& objects, double scale_factor, int min_neighbors){
/*cv::Mat image;
cv::CascadeClassifier cascade_classifier;
cascade_classifier.load(*cascade_file);
cascade_classifier.detectMultiScale(image, objects, scale_factor, min_neighbors, 0 | CASCADE_SCALE_IMAGE, Size(20, 20));
*/
}
void CascadeHandler::cascade_classifier_gpu(const string *cascade_file, std::vector<cv::Rect>& objects, double scale_factor, int min_neighbors){
/*Mat image;
cv::CascadeClassifier cascade_classifier;
*/
}
void CascadeHandler::handle(const string cascade_file, std::vector<cv::Rect>& objects, double scale_factor, int min_neighbors)
{
CascadeHandler cascade_handler;
cv::CascadeClassifier cascade_classifier;
//ocl::Context context;
/*
if (!cascade_classifier.load(cascade_file)){
cout << "[!] Error: You must load a Cascade file\n";
}
if (objects.empty()){
}
if (scale_factor == 0){
cout << "[!] Error: Unacceptable Scale Factor\n";
}
if (min_neighbors == 0){
cout << "[!] Error: Unacceptable Minimum Neighbors\n";
}
if (context.ndevices()){
cascade_handler.cascade_classifier_gpu(&cascade_file, objects, scale_factor, min_neighbors);
}
else if (!context.ndevices()){
cascade_handler.cascade_classifier_cpu(&cascade_file, objects, scale_factor, min_neighbors);
}
*/
}
void cascade_handler_wrapper(const string cascade_file, std::vector<cv::Rect>& objects,
double scale_factor, int min_neighbors){
CascadeHandler cascade_handler;
cascade_handler.handle(cascade_file, objects, scale_factor, min_neighbors);
}
BOOST_PYTHON_MODULE(cascade_handler){
def("handle", cascade_handler_wrapper);
}
The Header file
#ifndef _CASCADE_HANDLER
#define _CASCADE_HANDLER
#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/ocl/ocl.hpp>
using namespace std;
class CascadeHandler
{
public:
void cascade_classifier_cpu(const string *cascade_file, std::vector<cv::Rect>& objects, double scale_factor, int min_neighbors);
void cascade_classifier_gpu(const string *cascade_file, std::vector<cv::Rect>& objects, double scale_factor, int min_neighbors);
void handle(const string cascade_file, std::vector<cv::Rect>& objects, double scale_factor, int min_neighbors);
};
#endif
The Makefile
CPP = g++
CPPFLAGS = -g -Wall -std=c++11
INCLUDES = -I /usr/local/include
LDFLAGS = -L /usr/local/lib
ARCH := $$(getconf LONG_BIT)
CUDA_PATH = /opt/cuda
CUDA_LDFLAGS = -L$(CUDA_PATH)/lib$(ARCH)
CUDA_INCLUDES = -I$(CUDA_PATH)/include
OPENCV_LDFLAGS = $(CUDA_LDFLAGS)
OPENCV_LIBS = $$(pkg-config --libs opencv)
OPENCV_INCLUDES = $$(pkg-config --cflags opencv) $(CUDA_INCLUDES)
PYTHON_VER = 2
ifeq ($(PYTHON_VER), 2)
BOOST_LIBS = -lboost_python
else
BOOST_LIBS = -lboost_python$(PYTHON_VER)
endif
PYTHON_LIBS = $$(pkg-config --libs python$(PYTHON_VER))
PYTHON_INCLUDES = $$(pkg-config --cflags python$(PYTHON_VER))
TARGET = cascade_handler
all: $(TARGET).so
$(TARGET).so: $(TARGET).o
$(CPP) -shared -Wl,--export-dynamic $(LDFLAGS) \
$(OPENCV_LIBS) $(BOOST_LIBS) $(PYTHON_LIBS) \
$(TARGET).o -o $(TARGET).so
$(TARGET).o: $(TARGET).cpp
$(CPP) $(CPPFLAGS) $(INCLUDES) $(OPENCV_INCLUDES) $(PYTHON_INCLUDES) \
-fPIC -c $(TARGET).cpp
clean:
rm -f *.o *.so
And the Output
g++ -shared -Wl,--export-dynamic -L /usr/local/lib \
$(pkg-config --libs opencv) -lboost_python $(pkg-config --libs python2) \
cascade_handler.o -o cascade_handler.so
ld: unknown option: --export-dynamic
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [cascade_handler.so] Error 1
The linker error is the thing I can't quite fix. I wanted to have everything compile on a Makefile because I couldn't find a way to compile OpenCV with the setup.py you normally use when using boost::python. I've also read that some people have been using numpy to wrap their code in and then compile that way, but I was wondering if this method may also work? I also have most of the code commented out because I just wanted to test if it would compile by just have the class cv::CascadeClassifier cascade_classifier;