2 * Copyright (c) 2011. Philipp Wagner <bytefish[at]gmx[dot]de>.
3 * Released to public domain under terms of the BSD Simplified license.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of the organization nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
16 * See <http://www.opensource.org/licenses/bsd-license>
19 #include "opencv2/core.hpp"
20 #include "opencv2/contrib.hpp"
21 #include "opencv2/highgui.hpp"
22 #include "opencv2/imgproc.hpp"
23 #include "opencv2/objdetect.hpp"
32 static void read_csv(const string& filename, vector<Mat>& images, vector<int>& labels, char separator = ';') {
33 std::ifstream file(filename.c_str(), ifstream::in);
35 string error_message = "No valid input file was given, please check the given filename.";
36 CV_Error(CV_StsBadArg, error_message);
38 string line, path, classlabel;
39 while (getline(file, line)) {
40 stringstream liness(line);
41 getline(liness, path, separator);
42 getline(liness, classlabel);
43 if(!path.empty() && !classlabel.empty()) {
44 images.push_back(imread(path, 0));
45 labels.push_back(atoi(classlabel.c_str()));
50 int main(int argc, const char *argv[]) {
51 // Check for valid command line arguments, print usage
52 // if no arguments were given.
54 cout << "usage: " << argv[0] << " </path/to/haar_cascade> </path/to/csv.ext> </path/to/device id>" << endl;
55 cout << "\t </path/to/haar_cascade> -- Path to the Haar Cascade for face detection." << endl;
56 cout << "\t </path/to/csv.ext> -- Path to the CSV file with the face database." << endl;
57 cout << "\t <device id> -- The webcam device id to grab frames from." << endl;
60 // Get the path to your CSV:
61 string fn_haar = string(argv[1]);
62 string fn_csv = string(argv[2]);
63 int deviceId = atoi(argv[3]);
64 // These vectors hold the images and corresponding labels:
67 // Read in the data (fails if no valid input filename is given, but you'll get an error message):
69 read_csv(fn_csv, images, labels);
70 } catch (cv::Exception& e) {
71 cerr << "Error opening file \"" << fn_csv << "\". Reason: " << e.msg << endl;
72 // nothing more we can do
75 // Get the height from the first image. We'll need this
76 // later in code to reshape the images to their original
77 // size AND we need to reshape incoming faces to this size:
78 int im_width = images[0].cols;
79 int im_height = images[0].rows;
80 // Create a FaceRecognizer and train it on the given images:
81 Ptr<FaceRecognizer> model = createFisherFaceRecognizer();
82 model->train(images, labels);
83 // That's it for learning the Face Recognition model. You now
84 // need to create the classifier for the task of Face Detection.
85 // We are going to use the haar cascade you have specified in the
86 // command line arguments:
88 CascadeClassifier haar_cascade;
89 haar_cascade.load(fn_haar);
90 // Get a handle to the Video device:
91 VideoCapture cap(deviceId);
92 // Check if we can use this device at all:
94 cerr << "Capture Device ID " << deviceId << "cannot be opened." << endl;
97 // Holds the current frame from the Video device:
101 // Clone the current frame:
102 Mat original = frame.clone();
103 // Convert the current frame to grayscale:
105 cvtColor(original, gray, CV_BGR2GRAY);
106 // Find the faces in the frame:
107 vector< Rect_<int> > faces;
108 haar_cascade.detectMultiScale(gray, faces);
109 // At this point you have the position of the faces in
110 // faces. Now we'll get the faces, make a prediction and
111 // annotate it in the video. Cool or what?
112 for(int i = 0; i < faces.size(); i++) {
113 // Process face by face:
114 Rect face_i = faces[i];
115 // Crop the face from the image. So simple with OpenCV C++:
116 Mat face = gray(face_i);
117 // Resizing the face is necessary for Eigenfaces and Fisherfaces. You can easily
118 // verify this, by reading through the face recognition tutorial coming with OpenCV.
119 // Resizing IS NOT NEEDED for Local Binary Patterns Histograms, so preparing the
120 // input data really depends on the algorithm used.
122 // I strongly encourage you to play around with the algorithms. See which work best
123 // in your scenario, LBPH should always be a contender for robust face recognition.
125 // Since I am showing the Fisherfaces algorithm here, I also show how to resize the
126 // face you have just found:
128 cv::resize(face, face_resized, Size(im_width, im_height), 1.0, 1.0, INTER_CUBIC);
129 // Now perform the prediction, see how easy that is:
130 int prediction = model->predict(face_resized);
131 // And finally write all we've found out to the original image!
132 // First of all draw a green rectangle around the detected face:
133 rectangle(original, face_i, CV_RGB(0, 255,0), 1);
134 // Create the text we will annotate the box with:
135 string box_text = format("Prediction = %d", prediction);
136 // Calculate the position for annotated text (make sure we don't
137 // put illegal values in there):
138 int pos_x = std::max(face_i.tl().x - 10, 0);
139 int pos_y = std::max(face_i.tl().y - 10, 0);
140 // And now put it into the image:
141 putText(original, box_text, Point(pos_x, pos_y), FONT_HERSHEY_PLAIN, 1.0, CV_RGB(0,255,0), 2.0);
144 imshow("face_recognizer", original);
146 char key = (char) waitKey(20);
147 // Exit this loop on escape: