Add button to add ability to detect and draw faces in ImageFile view.

Author: jonathanrocher

stage5.2_fuller_application/pycasa/model/image_file.py

@@ -8,7 +8,7 @@
 
 # ETS imports
 from traits.api import Array, cached_property, Dict, File, HasStrictTraits, \
-    Property
+    List, Property
 
 SUPPORTED_FORMATS = [".png", ".jpg", ".jpeg"]
 
@@ -22,6 +22,8 @@ class ImageFile(HasStrictTraits):
 
     data = Property(Array, depends_on="filepath")
 
+    faces = List
+
     def to_array(self):
         file_ext = os.path.splitext(self.filepath)[1].lower()
         if not self.filepath or file_ext not in SUPPORTED_FORMATS:
@@ -60,4 +62,5 @@ def detect_faces(self, scale_factor=1.2, step_ratio=1, min_size=60,
                                             step_ratio=step_ratio,
                                             min_size=(min_size, min_size),
                                             max_size=(max_size, max_size))
+        self.faces = faces
         return faces

stage5.2_fuller_application/pycasa/ui/image_file_view.py

@@ -1,9 +1,10 @@
 # General imports
 from matplotlib.figure import Figure
+from matplotlib import patches
 
 # ETS imports
-from traits.api import Instance, observe
-from traitsui.api import Item, ModelView, View
+from traits.api import Button, Instance, observe
+from traitsui.api import HGroup, Item, ModelView, Spring, View
 
 # Local imports
 from ets_tutorial.util.mpl_figure_editor import MplFigureEditor
@@ -17,9 +18,16 @@ class ImageFileView(ModelView):
 
     figure = Instance(Figure)
 
+    detect_button = Button("Detect faces")
+
     view = View(
         Item("model.filepath", style="readonly", show_label=False),
-        Item("figure", editor=MplFigureEditor(), show_label=False)
+        Item("figure", editor=MplFigureEditor(), show_label=False),
+        HGroup(
+            Spring(),
+            Item("detect_button", show_label=False),
+            Spring(),
+        ),
     )
 
     @observe("model.filepath")
@@ -28,3 +36,21 @@ def build_mpl_figure(self, event):
         axes = figure.add_subplot(111)
         axes.imshow(self.model.to_array())
         self.figure = figure
+
+    def _detect_button_fired(self):
+        self.model.detect_faces()
+
+    @observe("model.faces")
+    def update_mpl_figure_with_faces(self, events):
+        axes = self.figure.get_axes()[0]
+        for face in self.model.faces:
+            axes.add_patch(
+                patches.Rectangle(
+                    (face['c'], face['r']),
+                    face['width'],
+                    face['height'],
+                    fill=False,
+                    color='r',
+                    linewidth=2
+                )
+            )