Added face detection python example

python_examples/face_detector.py

+#!/usr/bin/python
+# The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
+#
+# COMPILING THE DLIB PYTHON INTERFACE
+#   Dlib comes with a compiled python interface for python 2.7 on MS Windows.  If
+#   you are using another python version or operating system then you need to
+#   compile the dlib python interface before you can use this file.  To do this,
+#   run compile_dlib_python_module.bat.  This should work on any operating system
+#   so long as you have CMake and boost-python installed.  On Ubuntu, this can be
+#   done easily by running the command:  sudo apt-get install libboost-python-dev cmake
+
+import dlib, sys
+from skimage import io
+
+
+detector = dlib.get_frontal_face_detector()
+win = dlib.image_window()
+
+for f in sys.argv[1:]:
+    print "processing file: ", f
+    img = io.imread(f)
+    dets = detector(img,1)
+    print "number of faces detected: ", len(dets)
+
+    win.clear_overlay()
+    win.set_image(img)
+    win.add_overlay(dets)
+
+    raw_input("Hit enter to continue")
+
+