Add DAISY visualization + example plot.

doc/examples/plot_daisy.py

@@ -0,0 +1,28 @@
+"""
+===============================
+Dense DAISY feature description
+===============================
+
+The DAISY local image descriptor is based on gradient orientation histograms
+similar to the SIFT descriptor. It is formulated in a way that allows for fast
+dense extraction which is useful for e.g. bag-of-features image
+representations.
+
+In this example a limited number of DAISY descriptors are extracted at a large
+scale for illustrative purposes.
+"""
+
+from skimage.feature import daisy
+from skimage import data
+import matplotlib.pyplot as plt
+
+
+img = data.camera()
+descs, descs_img = daisy(img, step=180, radius=58, rings=2, histograms=6,
+                         orientations=8, visualize=True)
+
+plt.axis('off')
+plt.imshow(descs_img)
+descs_num = descs.shape[0] * descs.shape[1]
+plt.title('%i DAISY descriptors extracted:' % descs_num)
+plt.show()