Added an example showing how to use OpenCV's frame grabber

for face pose estimation.

examples/CMakeLists.txt

@@ -97,3 +97,15 @@ add_example(train_object_detector)
 add_example(train_shape_predictor_ex)
 add_example(using_custom_kernels_ex)
 add_example(xml_parser_ex)
+
+
+find_package(OpenCV)
+if (OpenCV_FOUND)
+   include_directories(${OpenCV_INCLUDE_DIRS})
+
+   ADD_EXECUTABLE(webcam_face_pose_ex webcam_face_pose_ex.cpp)
+   TARGET_LINK_LIBRARIES(webcam_face_pose_ex dlib ${OpenCV_LIBS} )
+endif()
+
+
+

examples/webcam_face_pose_ex.cpp

+// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
+/*
+
+    This example program shows how to find frontal human faces in an image and
+    estimate their pose.  The pose takes the form of 68 landmarks.  These are
+    points on the face such as the corners of the mouth, along the eyebrows, on
+    the eyes, and so forth.  
+    
+
+    This example is essentially just a version of the face_landmark_detection_ex.cpp
+    example modified to use OpenCV's VideoCapture object to read from a camera instead 
+    of files.
+
+
+    Finally, note that the face detector is fastest when compiled with at least
+    SSE2 instructions enabled.  So if you are using a PC with an Intel or AMD
+    chip then you should enable at least SSE2 instructions.  If you are using
+    cmake to compile this program you can enable them by using one of the
+    following commands when you create the build project:
+        cmake path_to_dlib_root/examples -DUSE_SSE2_INSTRUCTIONS=ON
+        cmake path_to_dlib_root/examples -DUSE_SSE4_INSTRUCTIONS=ON
+        cmake path_to_dlib_root/examples -DUSE_AVX_INSTRUCTIONS=ON
+    This will set the appropriate compiler options for GCC, clang, Visual
+    Studio, or the Intel compiler.  If you are using another compiler then you
+    need to consult your compiler's manual to determine how to enable these
+    instructions.  Note that AVX is the fastest but requires a CPU from at least
+    2011.  SSE4 is the next fastest and is supported by most current machines.  
+*/
+
+#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/gui_widgets.h>
+
+using namespace dlib;
+using namespace std;
+
+int main()
+{
+    try
+    {
+        cv::VideoCapture cap(0);
+        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://sourceforge.net/projects/dclib/files/dlib/v18.10/shape_predictor_68_face_landmarks.dat.bz2" << endl;
+        cout << endl << e.what() << endl;
+    }
+    catch(exception& e)
+    {
+        cout << e.what() << endl;
+    }
+}
+