MATLAB: How to middle

image processingMATLAB

i want to find middle

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If you have only circle on the image like below

clc,clear
I = imread('img.png');
I1 = im2bw(I,graythresh(I));        % binarize image (0,1)
[row, col] = find(I1);              % find white pixels (1 value)
ix = round( mean(col) );            % mean column
iy = round( mean(row) );            % mean row
imshow(I1)
hold on
plot(ix,iy,'or')
text(ix+10,iy+10,'CircleCenter')
hold off

Related Solutions

MATLAB: Get the Centroid of a specific object in an image

I = imread("image.png") ; 
[y,x] = find(I==0) ; 
iwant = [mean(x) mean(y)] ; 
% check 
imshow(I) 
hold on
plot(iwant(1),iwant(2),'+r')

MATLAB: How to create a matrix that has zero in middle

The line

x(size(n)-A:end-1,size(n)-A:end-1)=0;

is full of bugs.

First, what is the output of size(n)? It's guaranteed to be a vector with at least 2 elements (more for N-D arrays).

So size(n)-A is a vector with at least 2 elements.

Now what happens when you use a vector with the : operator? It's actually documented: If you specify nonscalar arrays, then MATLAB interprets j:i:k as j(1):i(1):k(1). So, you're always using the 1st index of the vector returned by size, which is the size of the first dimension.

The code you've written is equivalent to

x(size(n, 1)-A:end-1,size(n, 1)-A:end-1)=0;
%         ^                  ^
%         |                  |
%         --------------------------------- dimensions being indexed. Always 1

Notice the dimensions you index in size. Are they correct?

The second issue, of course, is that if the intent is for the zeros to be centered in the matrix, you ought to calculate the location of that centre, which you typically get by dividing the size by 2. So somewhere in the code there should be a division by 2,

As this looks like homework, I'm not giving the solution, but that should get you going.

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Related Solutions

MATLAB: Get the Centroid of a specific object in an image

MATLAB: How to create a matrix that has zero in middle

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