Removing black patches from an image

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Soumyadip
Soumyadip on 30 Mar 2013
Commented: Image Analyst on 3 Nov 2018
Hi,
I have the following image
I want to remove the black noisy regions on the right hand side, so as to keep only the digits in black and the rest in white. How to proceed?
  3 Comments
Soumyadip
Soumyadip on 30 Mar 2013
how to do that? I am a rookie to image processing in matlab. It would be kind if you specify further.
Image Analyst
Image Analyst on 31 Mar 2013
That threshold was a disaster. It's just an example for you to learn where global thresholds don't work when you have large global gradients. There really is no point at all in trying to fix this image or doing what you ask. It's much better to avoid the problem in the first place. I solved it in your duplicate question using color segmentation - take a look back at your original question.

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Answers (2)

Walter Roberson
Walter Roberson on 30 Mar 2013
blueimage = originalimage(:,:,3);
bwimage = blueimage >= threshold;
  2 Comments
Soumyadip
Soumyadip on 30 Mar 2013
I tried that but still it is having some black regions(although lesser than the previous). Can you suggest any method to remove such noise?? What exactly is such noise called??
Walter Roberson
Walter Roberson on 30 Mar 2013
For example, if the original image is "I", have a look at
T = I;T(T(:,:,[3 3 3])<64 | T(:,:,[1 1 1])>80) = 255;image(T)

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fateme moein
fateme moein on 3 Nov 2018
how to delete the dark areas in image processing?
  1 Comment
Image Analyst
Image Analyst on 3 Nov 2018
This is not an Answer to soumyadip's question.
What does "delete" mean to you?
Please read this link then post your question in a new thread.

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