How to remove an unwanted extension of a threshold?

Question

This is the thresholded image in context. The part that is unwanted is the extension on the top, I hope it's deducible. If it isn't, please ask. I want the almost circular part that would remain after removing the extension in context. How do I go about doing it? I've had someone suggest morphologial operation would help. Could someone please expand on that, and maybe provide an example?

Thanks

Here's another example:

i think if you share your code and original images you will get better ideas to achieve what you want — sturkmen, Apr 10 '16 at 09:57
Morphological opening could help with the first example, but not with the second. — vsz, Apr 16 '16 at 11:16

score 5 · Answer 1 · answered Apr 13 '16 at 11:51

The best practice would be, since you only need shapes similar to circle. Try using curve fitting along with Kalman Filter. Hope this would definitely tackle the problem in a more efficient way. circle equation will try to pull(correct) the points towards the center and Kalman will help trace the curve effectively.

score 0 · Answer 2 · answered Apr 30 '16 at 19:36

0

Your image is like a piece of flat plane3D view of your image . OTSU is not always a good idea. Disable it and choose a manual threshold (75).

answered Apr 30 '16 at 19:36

LBerger

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score 0 · Answer 3 · answered May 03 '16 at 00:53

from scipy import misc
from skimage.morphology import erosion    
data = misc.imread('gycl1.jpg')
eroded = erosion(data, disk(25)

Is this what you meant? I am using the erosion morphological operator with a disk size (to maintain the circular function).

How to remove an unwanted extension of a threshold?

3 Answers3