MATLAB: How detect spot white circle on image

Image Processing Toolboxspot white detection

I would like detect spot white are like below image . Hope anyone help . Thanks!

Best Answer

I = imread('Screen Shot 2017-06-06 at 3.54.58 PM.png') ;
im = imclearborder(im2bw(I));
im_fill = imfill(im, 'holes');
s = regionprops(im_fill, 'Area', 'PixelList');
[~,ind] = max([s.Area]);
pix = sub2ind(size(im), s(ind).PixelList(:,2), s(ind).PixelList(:,1));
out = zeros(size(im));
out(pix) = im(pix);
%  imshow(out);
[y,x] = find(out) ;
idx = boundary(x,y) ;
% idx = convhull(x,y) ;
imshow(I)
hold on
plot(x(idx),y(idx),'r','linewidth',3)

Code taken from: https://in.mathworks.com/matlabcentral/answers/343337-how-to-remove-small-portion-in-an-image

If boundary doesn't work, use convexhull

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MATLAB: How to cut out the white border in this binary image, but keep the rest

Another possible way is to use bwconvfull function, like:

% Read and binarize the image
I = imread('inTT.png');
BW = imbinarize(rgb2gray(I));
% Delete white background using bwconvfull
BWConv = bwconvhull(~BW);
BW2 = BW & BWConv;

MATLAB: How to remove small portion in an image

the result is a binary image but the part is extracted.

if true
I=imread('liver.png');
im = imclearborder(im2bw(I));
im_fill = imfill(im, 'holes');
s = regionprops(im_fill, 'Area', 'PixelList');
[~,ind] = max([s.Area]);
pix = sub2ind(size(im), s(ind).PixelList(:,2), s(ind).PixelList(:,1));
out = zeros(size(im));
out(pix) = im(pix);
imshow(out);  end

Best Answer

Related Solutions

MATLAB: How to cut out the white border in this binary image, but keep the rest

MATLAB: How to remove small portion in an image

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