title: How to draw a vertical line on image in php
body: <p>i am making an antibot that displays different pictures, and asks the user to click on a specific picture. However, i would like some small random change to be made to the picture each time, so that software could not analyze and determine which picture is beeing displayed...</p>
  
  <p>I would like one horizontal and one vertical line to be added at random coordinates with random color to the picture each time, then display the picture using get_file_contents and header.</p>
  
  <p>Hope this makes sense...  I would not want the changes to be saved to the picture, but only displayed to the user... I am using file_get_contents and header to display the picture, like this:</p>
  
  <pre><code>$id = $_GET['id'];
  $image = "images/".$id . ".jpg";
  $content = file_get_contents($image); 
  header('Content-Type: image/jpeg');
  echo $content;
  exit()
  </code></pre>
  
  <p>Thanks...</p>