Added a python interface to the face recognition DNN model.

tools/python/CMakeLists.txt

@@ -25,6 +25,7 @@ set(python_srcs
    src/object_detection.cpp
    src/shape_predictor.cpp
    src/correlation_tracker.cpp
+   src/face_recognition.cpp
 )
 
 # Only add the GUI module if requested

tools/python/src/dlib.cpp

@@ -18,6 +18,7 @@ void bind_rectangles();
 void bind_object_detection();
 void bind_shape_predictors();
 void bind_correlation_tracker();
+void bind_face_recognition();
 
 #ifndef DLIB_NO_GUI_SUPPORT
 void bind_gui();
@@ -49,6 +50,7 @@ BOOST_PYTHON_MODULE(dlib)
     bind_object_detection();
     bind_shape_predictors();
     bind_correlation_tracker();
+    bind_face_recognition();
 #ifndef DLIB_NO_GUI_SUPPORT
     bind_gui();
 #endif

tools/python/src/face_recognition.cpp

@@ -0,0 +1,170 @@
+// Copyright (C) 2017  Davis E. King (davis@dlib.net)
+// License: Boost Software License   See LICENSE.txt for the full license.
+
+#include <dlib/python.h>
+#include <boost/shared_ptr.hpp>
+#include <dlib/matrix.h>
+#include <boost/python/slice.hpp>
+#include <dlib/geometry/vector.h>
+#include <dlib/dnn.h>
+#include <dlib/image_transforms.h>
+#include "indexing.h"
+
+
+using namespace dlib;
+using namespace std;
+using namespace boost::python;
+
+typedef matrix<double,0,1> cv;
+
+
+class face_recognition_model_v1
+{
+
+public:
+
+    face_recognition_model_v1(const std::string& model_filename)
+    {
+        deserialize(model_filename) >> net;
+
+        cropper = make_shared<random_cropper>();
+        cropper->set_chip_dims(150,150);
+        cropper->set_randomly_flip(true);
+        cropper->set_max_object_height(0.99999);
+        cropper->set_background_crops_fraction(0);
+        cropper->set_min_object_height(0.97);
+        cropper->set_translate_amount(0.02);
+        cropper->set_max_rotation_degrees(3);
+    }
+
+    matrix<double,0,1> compute_face_descriptor (
+        object img,
+        const full_object_detection& face,
+        const int num_jitters
+    )
+    {
+        std::vector<full_object_detection> faces(1, face);
+        return compute_face_descriptors(img, faces, num_jitters)[0];
+    }
+
+    std::vector<matrix<double,0,1>> compute_face_descriptors (
+        object img,
+        const std::vector<full_object_detection>& faces,
+        const int num_jitters
+    )
+    {
+        if (!is_rgb_python_image(img))
+            throw dlib::error("Unsupported image type, must be RGB image.");
+
+        for (auto& f : faces)
+        {
+            if (f.num_parts() != 68)
+                throw dlib::error("The full_object_detection must use the iBUG 300W 68 point face landmark style.");
+        }
+
+
+        std::vector<chip_details> dets;
+        for (auto& f : faces)
+            dets.push_back(get_face_chip_details(f, 150, 0.25));
+        dlib::array<matrix<rgb_pixel>> face_chips;
+        extract_image_chips(numpy_rgb_image(img), dets, face_chips);
+
+        std::vector<matrix<double,0,1>> face_descriptors;
+        face_descriptors.reserve(face_chips.size());
+
+        if (num_jitters <= 1)
+        {
+            // extract descriptors and convert from float vectors to double vectors
+            for (auto& d : net(face_chips,16))
+                face_descriptors.push_back(matrix_cast<double>(d));
+        }
+        else
+        {
+            for (auto& fimg : face_chips)
+                face_descriptors.push_back(matrix_cast<double>(mean(mat(net(jitter_image(fimg,num_jitters),16)))));
+        }
+
+        return face_descriptors;
+    }
+
+private:
+
+    std::shared_ptr<random_cropper> cropper;
+
+    std::vector<matrix<rgb_pixel>> jitter_image(
+        const matrix<rgb_pixel>& img,
+        const int num_jitters
+    )
+    {
+        std::vector<mmod_rect> raw_boxes(1), ignored_crop_boxes;
+        raw_boxes[0] = shrink_rect(get_rect(img),3);
+        std::vector<matrix<rgb_pixel>> crops; 
+
+        matrix<rgb_pixel> temp; 
+        for (int i = 0; i < num_jitters; ++i)
+        {
+            (*cropper)(img, raw_boxes, temp, ignored_crop_boxes);
+            crops.push_back(move(temp));
+        }
+        return crops;
+    }
+
+
+    template <template <int,template<typename>class,int,typename> class block, int N, template<typename>class BN, typename SUBNET>
+    using residual = add_prev1<block<N,BN,1,tag1<SUBNET>>>;
+
+    template <template <int,template<typename>class,int,typename> class block, int N, template<typename>class BN, typename SUBNET>
+    using residual_down = add_prev2<avg_pool<2,2,2,2,skip1<tag2<block<N,BN,2,tag1<SUBNET>>>>>>;
+
+    template <int N, template <typename> class BN, int stride, typename SUBNET> 
+    using block  = BN<con<N,3,3,1,1,relu<BN<con<N,3,3,stride,stride,SUBNET>>>>>;
+
+    template <int N, typename SUBNET> using ares      = relu<residual<block,N,affine,SUBNET>>;
+    template <int N, typename SUBNET> using ares_down = relu<residual_down<block,N,affine,SUBNET>>;
+
+    template <typename SUBNET> using alevel0 = ares_down<256,SUBNET>;
+    template <typename SUBNET> using alevel1 = ares<256,ares<256,ares_down<256,SUBNET>>>;
+    template <typename SUBNET> using alevel2 = ares<128,ares<128,ares_down<128,SUBNET>>>;
+    template <typename SUBNET> using alevel3 = ares<64,ares<64,ares<64,ares_down<64,SUBNET>>>>;
+    template <typename SUBNET> using alevel4 = ares<32,ares<32,ares<32,SUBNET>>>;
+
+    using anet_type = loss_metric<fc_no_bias<128,avg_pool_everything<
+                                alevel0<
+                                alevel1<
+                                alevel2<
+                                alevel3<
+                                alevel4<
+                                max_pool<3,3,2,2,relu<affine<con<32,7,7,2,2,
+                                input_rgb_image_sized<150>
+                                >>>>>>>>>>>>;
+    anet_type net;
+};
+
+
+// ----------------------------------------------------------------------------------------
+
+void bind_face_recognition()
+{
+    using boost::python::arg;
+    {
+    class_<face_recognition_model_v1>("face_recognition_model_v1", "This object maps human faces into 128D vectors where pictures of the same person are mapped near to each other and pictures of different people are mapped far apart.  The constructor loads the face recognition model from a file. The model file is available here: http://dlib.net/files/dlib_face_recognition_resnet_model_v1.dat.bz2", init<std::string>())
+        .def("compute_face_descriptor", &face_recognition_model_v1::compute_face_descriptor, (arg("img"),arg("face"),arg("num_jitters")=0),
+            "Takes an image and a full_object_detection that references a face in that image and converts it into a 128D face descriptor. "
+            "If num_jitters>1 then each face will be randomly jittered slightly num_jitters times, each run through the 128D projection, and the average used as the face descriptor."
+            )
+        .def("compute_face_descriptor", &face_recognition_model_v1::compute_face_descriptors, (arg("img"),arg("faces"),arg("num_jitters")=0),
+            "Takes an image and an array of full_object_detections that reference faces in that image and converts them into 128D face descriptors.  "
+            "If num_jitters>1 then each face will be randomly jittered slightly num_jitters times, each run through the 128D projection, and the average used as the face descriptor."
+            );
+    }
+
+    {
+    typedef std::vector<full_object_detection> type;
+    class_<type>("full_object_detections", "An array of full_object_detection objects.")
+        .def(vector_indexing_suite<type>())
+        .def("clear", &type::clear)
+        .def("resize", resize<type>)
+        .def_pickle(serialize_pickle<type>());
+    }
+}
+