title: Why does hough not find line?
body: <p>I use the following code to extract lines from a given 25x25 black&amp;white-image:</p>
  
  <pre><code>[H, theta, rho] = hough(image);
  peaks = houghpeaks(H, 20,'NHoodSize',[19 19]);
  lines = houghlines(image, theta, rho, peaks, 'FillGap', 1, 'MinLength', 3);
  </code></pre>
  
  <p>I then plot the found lines on the given image. The result looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/z2KpL.png" alt="The lines found by my hough transform"></p>
  
  <p>What I can't understand is, why this procedure does not find a line on the left border of the image, going from top to bottom (or vice versa). Instead for example the pink line is found, which I would think has less evidence in hough space to be there (since it touches less white pixels).
  Does anyone have an intuition why this might be the case?</p>
  
  <p>I tried changing the parameters a little bit or add some padding to the image, but nothing has worked so far.</p>
  
  <p>edit:
  original image as requested:</p>
  
  <p><img src="https://i.stack.imgur.com/B5oOc.png" alt="original image"></p>
  
  <p>In </p>