如何在使用Dlib的opencv C ++中的地标提取中使用“ shape_predictor_68_face_landmarks.dat”

Question

I'm trying to run the following code and detect the facial landmarks of the frames which are taken from webcam.

#include <dlib/opencv.h>
#include <opencv2/highgui/highgui.hpp>
#include <dlib/image_processing/frontal_face_detector.h>
#include <dlib/image_processing/render_face_detections.h>
#include <dlib/image_processing.h>
#include <dlib/gui_widgets.h>

using namespace dlib;
using namespace std;

int main()
{
    try
    {
        cv::VideoCapture cap(0);
        if (!cap.isOpened())
        {
            cerr << "Unable to connect to camera" << endl;
            return 1;
        }

        image_window win;

        // Load face detection and pose estimation models.
        frontal_face_detector detector = get_frontal_face_detector();
        shape_predictor pose_model;
        deserialize("shape_predictor_68_face_landmarks.dat") >> pose_model;

        // Grab and process frames until the main window is closed by the user.
        while(!win.is_closed())
        {
            // Grab a frame
            cv::Mat temp;
            cap >> temp;
            // Turn OpenCV's Mat into something dlib can deal with.  Note that this just
            // wraps the Mat object, it doesn't copy anything.  So cimg is only valid as
            // long as temp is valid.  Also don't do anything to temp that would cause it
            // to reallocate the memory which stores the image as that will make cimg
            // contain dangling pointers.  This basically means you shouldn't modify temp
            // while using cimg.
            cv_image<bgr_pixel> cimg(temp);

            // Detect faces 
            std::vector<rectangle> faces = detector(cimg);
            // Find the pose of each face.
            std::vector<full_object_detection> shapes;
            for (unsigned long i = 0; i < faces.size(); ++i)
                shapes.push_back(pose_model(cimg, faces[i]));

            // Display it all on the screen
            win.clear_overlay();
            win.set_image(cimg);
            win.add_overlay(render_face_detections(shapes));
        }
    }
    catch(serialization_error& e)
    {
        cout << "You need dlib's default face landmarking model file to run this example." << endl;
        cout << "You can get it from the following URL: " << endl;
        cout << "   http://dlib.net/files/shape_predictor_68_face_landmarks.dat.bz2" << endl;
        cout << endl << e.what() << endl;
    }
    catch(exception& e)
    {
        cout << e.what() << endl;
    }
}

But when executing this .cpp file it gives the console output like this.

enter image description here

As in this I have download shape_predictor_68_face_landmarks.dat. But I don't know where to add this .dat and whish directory to include. Could anyone tell me how to use this shape_predictor_68_face_landmarks.dat.

Answer 1

The error seems to be from:

deserialize("shape_predictor_68_face_landmarks.dat") >> pose_model;

And Fix for the above would be to provide a full qualified path as:

deserialize("/full/path/to/shape_predictor_68_face_landmarks.dat") >> pose_model;

This is probably due to the reason that the C++ executable file can be ran from some build location to which this file may not be in local scope and hence it is unable to find it, The best way would be to use full qualified paths.