Python “Fast normalized cross correlation”
I am trying to use the implementation of "Fast Normalized cross correlation" ( http://pastebin.com/x1NJqWWm ) in python to do some template matching. However, even for simple test-images, it produces values out of the [-1:1] range. I can't see what I am doing wrong. Is there a limitation of this algorithm? Help would be much appreciated!
example:
# Template creation
t = np.zeros((4,4))
t[:,0:3] = 1
# Image creation
image = np.zeros((15,15)) # image
k=1
for i in range(len(image)):
if k==1:
image[i,:]=1
image[:,i]=1
k=0
else:
k=1
# Fast Normalized Cross Correlation
TM = norm_xcorr.TemplateMatch(t, method='both')
result2, ssd = TM(image)
This gives values out of the [-1:1] range:
>>> np.max(result2)
Out[6]: 8.4913641920299376
>>> np.min(result2)
Out[7]: -3.1869961773458306
python performance correlation
asked Feb 2 '15 at 16:39
sb9911
62
add a comment |
I am trying to use the implementation of "Fast Normalized cross correlation" ( http://pastebin.com/x1NJqWWm ) in python to do some template matching. However, even for simple test-images, it produces values out of the [-1:1] range. I can't see what I am doing wrong. Is there a limitation of this algorithm? Help would be much appreciated!
example:
# Template creation
t = np.zeros((4,4))
t[:,0:3] = 1
# Image creation
image = np.zeros((15,15)) # image
k=1
for i in range(len(image)):
if k==1:
image[i,:]=1
image[:,i]=1
k=0
else:
k=1
# Fast Normalized Cross Correlation
TM = norm_xcorr.TemplateMatch(t, method='both')
result2, ssd = TM(image)
This gives values out of the [-1:1] range:
>>> np.max(result2)
Out[6]: 8.4913641920299376
>>> np.min(result2)
Out[7]: -3.1869961773458306
python performance correlation
asked Feb 2 '15 at 16:39
sb9911
62
add a comment |
I am trying to use the implementation of "Fast Normalized cross correlation" ( http://pastebin.com/x1NJqWWm ) in python to do some template matching. However, even for simple test-images, it produces values out of the [-1:1] range. I can't see what I am doing wrong. Is there a limitation of this algorithm? Help would be much appreciated!
example:
# Template creation
t = np.zeros((4,4))
t[:,0:3] = 1
# Image creation
image = np.zeros((15,15)) # image
k=1
for i in range(len(image)):
if k==1:
image[i,:]=1
image[:,i]=1
k=0
else:
k=1
# Fast Normalized Cross Correlation
TM = norm_xcorr.TemplateMatch(t, method='both')
result2, ssd = TM(image)
This gives values out of the [-1:1] range:
>>> np.max(result2)
Out[6]: 8.4913641920299376
>>> np.min(result2)
Out[7]: -3.1869961773458306
python performance correlation
asked Feb 2 '15 at 16:39
sb9911
62
I am trying to use the implementation of "Fast Normalized cross correlation" ( http://pastebin.com/x1NJqWWm ) in python to do some template matching. However, even for simple test-images, it produces values out of the [-1:1] range. I can't see what I am doing wrong. Is there a limitation of this algorithm? Help would be much appreciated!
example:
# Template creation
t = np.zeros((4,4))
t[:,0:3] = 1
# Image creation
image = np.zeros((15,15)) # image
k=1
for i in range(len(image)):
if k==1:
image[i,:]=1
image[:,i]=1
k=0
else:
k=1
# Fast Normalized Cross Correlation
TM = norm_xcorr.TemplateMatch(t, method='both')
result2, ssd = TM(image)
This gives values out of the [-1:1] range:
>>> np.max(result2)
Out[6]: 8.4913641920299376
>>> np.min(result2)
Out[7]: -3.1869961773458306
python performance correlation
python performance correlation
asked Feb 2 '15 at 16:39
sb9911
62
asked Feb 2 '15 at 16:39
sb9911
62
asked Feb 2 '15 at 16:39
sb9911
62
asked Feb 2 '15 at 16:39
sb9911
62
asked Feb 2 '15 at 16:39
sb9911
62
62
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
It's already available in skimage source code
Also see this: https://dsp.stackexchange.com/questions/28322/python-normalized-cross-correlation-to-measure-similarites-in-2-images
answered Nov 22 '18 at 21:37
seralouk
5,66522338
add a comment |
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1 Answer
1
active
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1 Answer
1
active
oldest
votes
active
oldest
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active
oldest
votes
It's already available in skimage source code
Also see this: https://dsp.stackexchange.com/questions/28322/python-normalized-cross-correlation-to-measure-similarites-in-2-images
answered Nov 22 '18 at 21:37
seralouk
5,66522338
add a comment |
It's already available in skimage source code
Also see this: https://dsp.stackexchange.com/questions/28322/python-normalized-cross-correlation-to-measure-similarites-in-2-images
answered Nov 22 '18 at 21:37
seralouk
5,66522338
add a comment |
It's already available in skimage source code
Also see this: https://dsp.stackexchange.com/questions/28322/python-normalized-cross-correlation-to-measure-similarites-in-2-images
answered Nov 22 '18 at 21:37
seralouk
5,66522338
It's already available in skimage source code
Also see this: https://dsp.stackexchange.com/questions/28322/python-normalized-cross-correlation-to-measure-similarites-in-2-images
answered Nov 22 '18 at 21:37
seralouk
5,66522338
answered Nov 22 '18 at 21:37
seralouk
5,66522338
answered Nov 22 '18 at 21:37
seralouk
5,66522338
answered Nov 22 '18 at 21:37
seralouk
5,66522338
5,66522338
add a comment |
add a comment |
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