OpenCv and Visual C++ Face detection - c++

Question

I am currently trying to write a face detection program and i seem to have a slight problem with it even though it is able to build successfully. Any ideas on how to solve this? Below indicates the error that appears when i debug and my code.
detect.cpp:
#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/videoio.hpp>
#include <opencv2/objdetect.hpp>
#include <opencv2/imgproc.hpp>
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
// capture from web camera init
VideoCapture cap(0);
cap.open(0);
Mat img;
// Initialize the inbuilt Harr Cascade frontal face detection
// Below mention the path of where your haarcascade_frontalface_alt2.xml file is located
CascadeClassifier face_cascade;
face_cascade.load("C:\OpenCV\sources\data\haarcascades\haarcascade_frontalface_alt2.xml");
// i tried changing this line to match my folder in C Drive
for (;;)
{
// Image from camera to Mat
cap >> img;
// obtain input image from source
cap.retrieve(img, CV_CAP_OPENNI_BGR_IMAGE);
// Just resize input image if you want
resize(img, img, Size(1000, 640));
// Container of faces
vector<Rect> faces;
// Detect faces
face_cascade.detectMultiScale(img, faces, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(140, 140));
// error message appears here
//Show the results
// Draw circles on the detected faces
for (int i = 0; i < faces.size(); i++)
{
Point center(faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5);
ellipse(img, center, Size(faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar(255, 0, 255), 4, 8, 0);
}
// To draw rectangles around detected faces
/* for (unsigned i = 0; i<faces.size(); i++)
rectangle(img,faces[i], Scalar(255, 0, 0), 2, 1);*/
imshow("wooohooo", img);
int key2 = waitKey(20);
}
return 0;
}
error message:
Unhandled exception at 0x000007FEFD5CA06D in opencvTry.exe: Microsoft C++ exception: cv::Exception at memory location 0x000000000029EE10. occurred

Answer 1

After i looked at my codes one by one, i realized that it was just the back slash that causes the error. The code i used in the above was this :
face_cascade.load("C:\OpenCV\sources\data\haarcascades\haarcascade_frontalface_alt2.xml");
But in actual fact, it should have been this:
face_cascade.load("C:/OpenCV/sources/data/haarcascades/haarcascade_frontalface_alt2.xml");