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How to remove specific line in the binary image?

Asked by YOUNG HYUN KIM on 13 Aug 2018
Latest activity Commented on by YOUNG HYUN KIM on 13 Aug 2018
Hi! I'm a student who study MATLAB my own.
In the image below I want to remove the connected lines that the red arrow points to and leave only the lines in the yellow box.
The final thing I want to do is count the number of pixels in the yellow box, so we will use the regionprops function.
I am wondering if there is a way to remove the connected lines pointed to by the yellow arrow and get the count when using the regionprops function.
I would be grateful if the experts would help me a little.

  1 Comment

attached the unedited binary image?

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2 Answers

Answer by KALYAN ACHARJYA on 13 Aug 2018
Edited by KALYAN ACHARJYA on 13 Aug 2018

Try this one, before applying the operation to convert the image to binary
% p Blob size, you can adjust accordingly


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Answer by Image Analyst
on 13 Aug 2018
Edited by Image Analyst
on 13 Aug 2018

It looks like you might have used bwboundaries to get the boundaries of the blobs, and that you don't want the interior boundaries. If that's the case, simply use imfill() before you call bwboundaries():
binaryImage = imfill(binaryImage, 'holes');
boundaries = bwboundaries(binaryImage);
or, more simply:
boundaries = bwboundaries(binaryImage, 'noholes');
if you don't want to change your binary image.
If you just want to mask out (erase to black) everything in the yellow box, simply make a mask and use it as an index
% Create the mask.
yellowBox = true(size(binaryImage));
yellowBox(row1:row2, col1:col2) = false;
% Do the masking.
maskedImage = grayImage; % Initialize a new copy.
maskedImage(yellowBox) = 0; % Erase outside the yellow box.
Of course you'll need to define the starting and stopping rows and columns.

  1 Comment

Thanks for your answer, Image Analyst!!!
I use below codes to get that image.
noff1=regionprops(eoff1, 'Area');
The Image that i attached on my question is the overlay image.
(use foff1=imoverlay(off1,eoff1,[0 1 0]))
In this code, how can i apply those code that you showed? Thanks.
I attatch a new figure 01.bmp!

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