Adaptation of the OpenCV LBP face recogniser demo to handle more than one image.

demo_lbph.cpp

/*
 * Copyright (c) 2011. Philipp Wagner <bytefish[at]gmx[dot]de>.
 * Released to public domain under terms of the BSD Simplified license.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of the organization nor the names of its contributors
 *     may be used to endorse or promote products derived from this software
 *     without specific prior written permission.
 *
 *   See <http://www.opensource.org/licenses/bsd-license>
 */
 
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"

#include "facerec.hpp"

#include <iostream>
#include <fstream>
#include <sstream>

using namespace cv;
using namespace std;

static void read_csv(const string& filename, vector<Mat>& images, vector<string>& labels, vector<int>& ids, vector<string>& todo, char separator = ';') {
    int lastid = 0;
    map<string, int> reverse;
    std::ifstream file(filename.c_str(), ifstream::in);
    if (!file) {
        string error_message = "No valid input file was given, please check the given filename.";
        CV_Error(CV_StsBadArg, error_message);
    }
    int lblcount = 0;
    string line, path, classlabel;
    while (getline(file, line)) {
        stringstream liness(line);
        getline(liness, path, separator);
        getline(liness, classlabel);
        if(classlabel.empty()) {
            todo.push_back(path);
	}
        if(!path.empty() && !classlabel.empty()) {
            images.push_back(imread(path, 0));
            if(std::find(labels.begin(), labels.end(), classlabel) == labels.end()) {
                labels.push_back(classlabel);
                reverse[classlabel] = lastid;
                lastid++;
            }
            ids.push_back(reverse[classlabel]);
        }
    }
}

int main(int argc, const char *argv[]) {
    // Check for valid command line arguments, print usage
    // if no arguments were given.
    if (argc != 2) {
        cout << "usage: " << argv[0] << " <csv.ext>" << endl;
        exit(1);
    }
    // Get the path to your CSV.
    string fn_csv = string(argv[1]);
    // These vectors hold the images and corresponding labels.
    vector<Mat> images;
    vector<string> labels;
    vector<int> ids;
    vector<string> todo;
    // Read in the data. This can fail if no valid
    // input filename is given.
    try {
        read_csv(fn_csv, images, labels, ids, todo);
    } catch (cv::Exception& e) {
        cerr << "Error opening file \"" << fn_csv << "\". Reason: " << e.msg << endl;
        // nothing more we can do
        exit(1);
    }
    // Quit if there are not enough images for this demo.
    if(images.size() <= 1) {
        string error_message = "This demo needs at least 2 images to work. Please add more images to your data set!";
        CV_Error(CV_StsError, error_message);
    }

    Ptr<FaceRecognizer> model = createLBPHFaceRecognizer();
    model->train(images, ids);
    // The following line predicts the label of a given
    // test image:
    for(vector<string>::iterator it = todo.begin(); it != todo.end(); it++) {
        Mat current = imread(*it, 0);
        int predictedLabel = model->predict(current);
        cout << *it << ";" << labels[predictedLabel] << endl;
    }

    return 0;
}