title: How do I save jpeg images with no compression in Matlab?
body: <p>How do I save jpeg images with no compression in Matlab?</p>
  
  <p>I tried </p>
  
  <pre><code>targetImageFile = 'skype2.png';
  targetImage = imread(targetImageFile);
  
  imwrite(targetImage,'output.png','Compression','none',...
         'WriteMode','append');
  </code></pre>
  
  <p>However, I got</p>
  
  <pre><code>input:
  compressionRatio      = 1.992735e+000
  output:
  compressionRatio      = 2.090858e+000
  </code></pre>
  
  <p>Thank you for your advice.</p>