extend hough line to infinity in matlab

To extend a Hough line to infinity in MATLAB, you can follow these steps:

1. Obtain the Hough parameters for the detected line(s) using houghlines function. This will give you the start and end points of the line in the image coordinate system.

main.m
[H,T,R] = hough(BW); % where BW is the binary image
P = houghpeaks(H,numpeaks); % where numpeaks is the number of lines you want to detect
lines = houghlines(BW,T,R,P,'FillGap',5,'MinLength',7);
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2. Calculate the slope and intercept of the line in the image coordinate system using the start and end points.

main.m
for k = 1:length(lines)
   xy = [lines(k).point1; lines(k).point2];
   slope = (xy(2,2) - xy(1,2)) / (xy(2,1) - xy(1,1));
   intercept = xy(1,2) - slope * xy(1,1);    
end
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3. Find two points on the line which are outside the bounds of the image. You can do this by extending the line to the edge of the image.

main.m
x1 = 1;
y1 = slope * x1 + intercept;
x2 = size(BW, 2);
y2 = slope * x2 + intercept;
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4. Plot the extended line using the line function in MATLAB.

main.m
figure, imshow(BW), hold on
plot([x1, x2], [y1, y2], 'LineWidth', 2, 'Color', 'red');
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This will plot the Hough line in red color and extend it to the edge of the image, making it appear as if it has infinite length.