write nonmaxsup from scratch in matlab

function output = nonmaxsup(input, orientation)

% Read in size of image
[m, n] = size(input);

% Initialize output
output = zeros(m, n);

% Compute magnitude and convert orientation from radians to degrees
magnitude = hypot(imag(input), real(input));
angle = orientation * 180/pi;

% Create a binary image based on the angle of orientation
angle(angle < -90) = angle(angle < -90) + 180;
angle(angle > 90) = angle(angle > 90) - 180;
angle(angle < 0) = angle(angle < 0) + 180;
angle = angle/180;
angle = round(angle * 4) + 1;

% Iterate through each pixel in the image
for i = 2:m-1
   for j = 2:n-1
       
       % Obtain the two pixel values adjacent to the current pixel
       p1 = magnitude(i-1,j-1);
       p2 = magnitude(i+1,j+1);
       
       % Compute the weighted average of the two pixels
       w1 = (p2 - magnitude(i,j))/(p2 - p1);
       weighted_average1 = w1*magnitude(i-1,j-1) + (1-w1)*magnitude(i+1,j+1);
       
       % Obtain the two other adjacent pixels
       p1 = magnitude(i-1,j+1);
       p2 = magnitude(i+1,j-1);
       
       % Compute the weighted average of these pixels
       w2 = (p2 - magnitude(i,j))/(p2 - p1);
       weighted_average2 = w2*magnitude(i-1,j+1) + (1-w2)*magnitude(i+1,j-1);
       
       % Compute a final weighted average based on the angle of the current pixel
       if angle(i,j) == 1 || angle(i,j) == 3
           output(i,j) = (magnitude(i,j) > weighted_average1) && (magnitude(i,j) > weighted_average2);
       else
           output(i,j) = (magnitude(i,j) > weighted_average1) && (magnitude(i,j) >= weighted_average2);
       end
   end
end
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