How to read the pixel value

I used the following code to get the x and y coordinates of this image

I =double(imread('F:\01.jpg'));
[ROWS,COLUMNS] = ndgrid(1:size(I,1),1:size(I,2));
ROWS = ROWS(:);
COLUMNS = COLUMNS(:);
A = [ROWS COLUMNS]

I want to get the another column in A stating the pixel value of each pixel point. The purpose is to get the x and y coordinates of the black pixels only in the shortest possible path order

Answer 1

[thitch]

You could use the following:

ind = 1:size(A,1);
A(:,3) = arrayfun(@(x) I(A(x,1),A(x,2)), ind)';

[Mech Stud]

Thanks much.