extend line to edge of image in matlab

main.m
% Load an image and detect edges
img = imread('example.png');
BW = edge(img, 'canny');

% Define a line segment
x0 = 50; y0 = 50;
x1 = 100; y1 = 100;

% Sample pixel values along the line
[pixel_vals, ~] = improfile(BW, [x0, x1], [y0, y1]);

% Compute the length of the line segment
len = norm([x1-x0, y1-y0]);

% Define points outside the image boundaries
x_out = [-len, 2*len] + x0;
y_out = [y0, y0];

% Interpolate to estimate pixel values at the outer points
f = griddedInterpolant([-(len+1), 0, len+1], [0, len/2, len]);
vals_out = f(pixel_vals);

% Plot the result
figure; imshow(BW); hold on;
plot([x0, x1], [y0, y1], 'r-', 'LineWidth', 2);
plot(x_out, y_out, 'gx');
plot(x_out, y_out, 'bo', 'MarkerFaceColor', 'b');
plot(x_out, y_out + vals_out, 'b-', 'LineWidth', 2);
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