title: How to convert jpg files into png files with linux command? + Difficulty = Subfolders
body: <p>I want to convert several jpg files into png files. As far as I know, one can use this command</p>
  
  <pre><code>mogrify -format png *.*
  </code></pre>
  
  <p>I have one problem, I have a lot of subfolders. Let's say <strong>a</strong> is my main folder and <strong>b,c</strong> and <strong>d</strong> are subfolders. The images are in the subfolders. </p>
  
  <p>How can I convert all images without having to open every folder manually?</p>
  
  <p>-> I would like to write a command that works, when I am in folder <strong>a</strong>, but works for all files in the subfolders.</p>