MATLAB Answers

How to fill a ROI without affecting outside?

4 views (last 30 days)
Steven on 17 Dec 2013
Commented: Neda on 15 Nov 2017
I want to specify an ROI (of a binary image) on screen (several times) and make its inside white but do not change the outside. How can I do so?
I used imfill, but it gives me only the choice of choosing one point.
How can I determine the locations (specified by the user on screen) for imfill?
I tried to use this simple code, but it does not do what I want:
ROI = imfreehand();
ROI_xy = floor(hFH.getPosition)
I also used
but it didn't work either.
Could someone help me please with this?
Thanks. Steven


Sign in to comment.

Accepted Answer

Image Analyst
Image Analyst on 17 Dec 2013
I thought I already showed you in a prior question where I attached my demo (attached again). Anyway, you need to get the binary mask:
hFH = imfreehand();
% Create a binary image ("mask") from the ROI object.
binaryImage = hFH.createMask();
Then use it to make the image white:
grayImage(binaryImage) = 255;
By the way, don't use Image as the name of a variable since image is the name of a built-in function and it will be confusing.

  1 Comment

Neda on 15 Nov 2017
I tried this to make a mask, but imfreehand isn't enough for me as it's not giving me the exact shape I need. any advice and suggestions will be greatly appreciated.

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!