get maxima of a gray scale image

get_local_maxima.m

function [I, J, xvals] = get_local_maxima(imcor, radius)
% a = rand(10);
% [I, J, xvals] = get_local_maxima(a, 3);
% figure, imagesc(a); hold on; scatter(J, I);

[m, n] = size(imcor);
nim = ones(m + radius * 2, n + radius * 2) * 1e-10;
nim(radius + (1:m), radius + (1:n)) = imcor;

cols = im2col(nim, [2*radius + 1, 2 * radius + 1], 'sliding');

mcols = max(cols);

o = imcor == reshape(mcols, m, n);

[I, J] = find(o);

xvals = imcor(sub2ind([m, n], I, J));

end

show_local_maxima.m

a = rand(10);

[I, J, xvals] = get_local_maxima(a, 3);

figure, imagesc(a); hold on; scatter(J, I);