Add save buttons to viewer example.

viewer_examples/plugins/canny_simple.py

@@ -3,18 +3,22 @@ from skimage.filter import canny
 
 from skimage.viewer import ImageViewer
 from skimage.viewer.widgets import Slider
+from skimage.viewer.widgets.history import SaveButtons
 from skimage.viewer.plugins.overlayplugin import OverlayPlugin
 
 
 image = data.camera()
-# Note: ImageViewer must be called before Plugin b/c it starts the event loop.
-viewer = ImageViewer(image)
+
 # You can create a UI for a filter just by passing a filter function...
 plugin = OverlayPlugin(image_filter=canny)
 # ... and adding widgets to adjust parameter values.
 plugin += Slider('sigma', 0, 5, update_on='release')
 plugin += Slider('low threshold', 0, 255, update_on='release')
 plugin += Slider('high threshold', 0, 255, update_on='release')
-# Finally, attach the plugin to the image viewer.
+# ... and we can also add buttons to save the overlay:
+plugin += SaveButtons(name='Save overlay to:')
+
+# Finally, attach the plugin to an image viewer.
+viewer = ImageViewer(image)
 viewer += plugin
 viewer.show()