trained-classifier.cpp

const string cascade_name = "$OPENCV_ROOT/data/haarcascades/haarcascade_frontalface_default.xml";
CascadeClassifier face_cascade;
if (not face_cascade.load(cascade_name)) {
     cerr << "Cannot load cascade classifier from file: " <<    cascade_name << endl;
return -1;
}
// ... obtain an image in img
vector<Rect> faces;
faceDetector(img, faces, face_cascade);
// Check if any faces were detected or not
if (faces.size() == 0) {
    cerr << "Cannot detect any faces in the image." << endl;
    return -1;
}