face_detection_dlib_hog.cpp

#include <iostream>
#include <string>
#include <vector>
#include <stdlib.h>
#include <opencv2/core.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/highgui.hpp>

#include <dlib/opencv.h>
#include <dlib/image_processing.h>
#include <dlib/image_processing/frontal_face_detector.h>

using namespace cv;
using namespace std;
using namespace dlib;

void detectFaceDlibHog(frontal_face_detector hogFaceDetector, Mat &frameDlibHog, int inHeight=300, int inWidth=0)
{

    int frameHeight = frameDlibHog.rows;
    int frameWidth = frameDlibHog.cols;
    if (!inWidth)
        inWidth = (int)((frameWidth / (float)frameHeight) * inHeight);

    float scaleHeight = frameHeight / (float)inHeight;
    float scaleWidth = frameWidth / (float)inWidth;

    Mat frameDlibHogSmall;
    resize(frameDlibHog, frameDlibHogSmall, Size(inWidth, inHeight));

    // Convert OpenCV image format to Dlib's image format
    cv_image<bgr_pixel> dlibIm(frameDlibHogSmall);

    // Detect faces in the image
    std::vector<dlib::rectangle> faceRects = hogFaceDetector(dlibIm);

    for ( size_t i = 0; i < faceRects.size(); i++ )
    {
        int x1 = (int)(faceRects[i].left() * scaleWidth);
        int y1 = (int)(faceRects[i].top() * scaleHeight);
        int x2 = (int)(faceRects[i].right() * scaleWidth);
        int y2 = (int)(faceRects[i].bottom() * scaleHeight);
        cv::rectangle(frameDlibHog, Point(x1, y1), Point(x2, y2), Scalar(0,255,0), (int)(frameHeight/150.0), 4);
    }
}


int main( int argc, const char** argv )
{
    frontal_face_detector hogFaceDetector = get_frontal_face_detector();

    VideoCapture source;
    if (argc == 1)
        source.open(0, CAP_V4L);
    else
        source.open(argv[1]);

    Mat frame;

    double tt_dlibHog = 0;
    double fpsDlibHog = 0;

    while (true)
    {
        source >> frame;
        if (frame.empty())
            break;

        double t = cv::getTickCount();
        detectFaceDlibHog(hogFaceDetector, frame);
        tt_dlibHog = ((double)cv::getTickCount() - t)/cv::getTickFrequency();
        fpsDlibHog = 1/tt_dlibHog;

        putText(frame, format("DLIB HoG; FPS = %.2f",fpsDlibHog), Point(10, 50), FONT_HERSHEY_SIMPLEX, 1.3, Scalar(0, 0, 255), 4);
        imshow("DLIB - HoG Face Detection", frame);

        int k = waitKey(5);
        if(k == 27)
        {
            destroyAllWindows();
            break;
        }
      }
}