Refactor the GUI code out

I also cleaned up a bunch of code. I'm not sure why the
simple_object_detector was keeping track of the upsample amount,
since it can't even be passed as an argument to the constructor.
Therefore, I removed the simple_object_detector_py and the second
declaration of the hog object detector. I also changed the
view code to optionally take keyword args of color and added
a single view of a rectangle.

Finally, I added viewing of the shape parts.

tools/python/CMakeLists.txt

@@ -24,6 +24,7 @@ add_python_module(dlib
    src/image.cpp
    src/object_detection.cpp
    src/shape_predictor.cpp
+   src/gui.cpp
    )
 
 # When you run "make install" we will copy the compiled dlib.so (or dlib.pyd) 

tools/python/src/dlib.cpp

@@ -16,7 +16,7 @@ void bind_svm_struct();
 void bind_image_classes();
 void bind_object_detection();
 void bind_shape_predictors();
-
+void bind_gui();
 
 BOOST_PYTHON_MODULE(dlib)
 {
@@ -37,5 +37,6 @@ BOOST_PYTHON_MODULE(dlib)
     bind_image_classes();
     bind_object_detection();
     bind_shape_predictors();
+    bind_gui();
 }
 

tools/python/src/gui.cpp

+#ifndef DLIB_NO_GUI_SUPPORT
+
+#include <dlib/python.h>
+#include <boost/python/args.hpp>
+#include <dlib/geometry.h>
+#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;
+using namespace boost::python;
+
+// ----------------------------------------------------------------------------------------
+
+// Forward declaration of the simple_object_detector
+typedef object_detector<scan_fhog_pyramid<pyramid_down<6> > > simple_object_detector;
+
+void image_window_set_image_fhog_detector (
+    image_window& win,
+    const frontal_face_detector& det
+)
+{
+    win.set_image(draw_fhog(det));
+}
+
+void image_window_set_image_simple_detector (
+    image_window& win,
+    const simple_object_detector& det
+)
+{
+    win.set_image(draw_fhog(det));
+}
+
+// ----------------------------------------------------------------------------------------
+
+void image_window_set_image (
+    image_window& win,
+    object img
+)
+{
+    if (is_gray_python_image(img))
+        return win.set_image(numpy_gray_image(img));
+    else if (is_rgb_python_image(img))
+        return win.set_image(numpy_rgb_image(img));
+    else
+        throw dlib::error("Unsupported image type, must be 8bit gray or RGB image.");
+}
+
+void add_overlay_rect (
+    image_window& win,
+    const rectangle& rect,
+    const rgb_pixel& color
+)
+{
+    std::vector<rectangle> rects;
+    rects.push_back(rect);
+    win.add_overlay(rects, color);
+}
+
+void add_overlay_parts (
+    image_window& win,
+    const full_object_detection& detection,
+    const rgb_pixel& color
+)
+{
+    std::vector<full_object_detection> detections;
+    detections.push_back(detection);
+    win.add_overlay(render_face_detections(detections, color));
+}
+
+boost::shared_ptr<image_window> make_image_window_from_image(object img)
+{
+    boost::shared_ptr<image_window> win(new image_window);
+    image_window_set_image(*win, img);
+    return win;
+}
+
+boost::shared_ptr<image_window> make_image_window_from_image_and_title(object img, const string& title)
+{
+    boost::shared_ptr<image_window> win(new image_window);
+    image_window_set_image(*win, img);
+    win->set_title(title);
+    return win;
+}
+
+// ----------------------------------------------------------------------------------------
+
+void bind_gui()
+{
+    using boost::python::arg;
+    {
+    typedef image_window type;
+    typedef void (image_window::*set_title_funct)(const std::string&);
+    typedef void (image_window::*add_overlay_funct)(const std::vector<rectangle>& r, rgb_pixel p);
+    class_<type,boost::noncopyable>("image_window",
+        "This is a GUI window capable of showing images on the screen.")
+        .def("__init__", make_constructor(&make_image_window_from_image),
+            "Create an image window that displays the given numpy image.")
+        .def("__init__", make_constructor(&make_image_window_from_image_and_title),
+            "Create an image window that displays the given numpy image and also has the given title.")
+        .def("set_image", image_window_set_image, arg("image"),
+            "Make the image_window display the given image.")
+        .def("set_image", image_window_set_image_fhog_detector, arg("detector"),
+            "Make the image_window display the given HOG detector's filters.")
+        .def("set_image", image_window_set_image_simple_detector, arg("detector"),
+            "Make the image_window display the given HOG detector's filters.")
+        .def("set_title", (set_title_funct)&type::set_title, arg("title"),
+            "Set the title of the window to the given value.")
+        .def("clear_overlay", &type::clear_overlay, "Remove all overlays from the image_window.")
+        .def("add_overlay", (add_overlay_funct)&type::add_overlay<rgb_pixel>, (arg("rectangles"), arg("color")=rgb_pixel(255, 0, 0)),
+            "Add a list of rectangles to the image_window. They will be displayed as red boxes by default, but the color can be passed.")
+        .def("add_overlay", add_overlay_rect, (arg("rectangle"), arg("color")=rgb_pixel(255, 0, 0)),
+            "Add a rectangle to the image_window.  It will be displayed as a red box by default, but the color can be passed.")
+        .def("add_overlay", add_overlay_parts, (arg("detection"), arg("color")=rgb_pixel(0, 0, 255)),
+            "Add full_object_detection parts to the image window. They will be displayed as blue lines by default, but the color can be passed.")
+        .def("wait_until_closed", &type::wait_until_closed,
+            "This function blocks until the window is closed.");
+    }
+}
+#endif