title: Should I use a PHP extension for ImageMagick or just use PHP's Exec() function to run the terminal commands?
body: <p>I need to do the following image manipulations for images uploaded by users on my site:</p>
  
  <ol>
  <li>Resize images (if greater than a certain dimension)</li>
  <li>Convert all image formats to jpg's</li>
  <li>Add a watermark to the bottom of all images</li>
  </ol>
  
  <p>Do I need to use either the MagickWand or iMagick extensions or can I just get away with running the terminal commands inside PHP's exec function?</p>
  
  <p>Is there a reason why the PHP extensions would be preferred? Which would be faster and better for performance (this site may have lots of users and there would be a ton of image processing at any given time)?</p>