Fix inconsistencies in examples and many more improvements

doc/examples/plot_view_as_blocks.py

@@ -12,8 +12,8 @@ blocks.  Then, on each block, we either pool the mean, the max or the
 median value of that block. The results are displayed altogether, along
 with a spline interpolation of order 3 rescaling of the original `lena`
 image.
-"""
 
+"""
 import numpy as np
 from scipy import ndimage as ndi
 from matplotlib import pyplot as plt