Source Code for Module pyvision.util.windows

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 3  # Copyright (c) 2006-2008 David S. Bolme 
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33   
34  import numpy as np 
35   
36 -def hammingWindow(size): 
37      ''' 
38      Windowing function from: 
39      http://en.wikipedia.org/wiki/Window_function 
40      ''' 
41      w,h = size 
42      X = np.arange(w).reshape(w,1) 
43      Y = np.arange(h).reshape(1,h) 
44      X = X*np.ones((1,h),'d') 
45      Y = Y*np.ones((w,1),'d') 
46       
47      window = (5.3836-0.46164*np.cos(2*np.pi*X/(w-1.0)))*(5.3836-0.46164*np.cos(2*np.pi*Y/(h-1.0))) 
48      return window 
49   
50   
51 -def hannWindow(size): 
52      ''' 
53      Windowing function from: 
54      http://en.wikipedia.org/wiki/Window_function 
55      ''' 
56      w,h = size 
57      X = np.arange(w).reshape(w,1) 
58      Y = np.arange(h).reshape(1,h) 
59      X = X*np.ones((1,h),'d') 
60      Y = Y*np.ones((w,1),'d') 
61       
62      window = (0.5*(1-np.cos(2*np.pi*X/(w-1.0))))*(0.5*(1-np.cos(2*np.pi*Y/(h-1.0)))) 
63      return window 
64   
65 -def cosineWindow(size): 
66      ''' 
67      Windowing function from: 
68      http://en.wikipedia.org/wiki/Window_function 
69      ''' 
70      w,h = size 
71      X = np.arange(w).reshape(w,1) 
72      Y = np.arange(h).reshape(1,h) 
73      X = X*np.ones((1,h),'d') 
74      Y = Y*np.ones((w,1),'d') 
75       
76      window = (np.sin(np.pi*X/(w-1.0)))*(np.sin(np.pi*Y/(h-1.0))) 
77      return window 
78