title: Using sklearn load_files() to load images from png as data
body: <p>I'm currently using sklearn to build a simple image recogniser.</p>
  
  <p>I need to use load_files('./directory/') to load images from sub-folders within that directory.</p>
  
  <p>It correctly gets the target values but the data attributes are not simple pixel values. I assume I need to set the encoding parameter to consider the image files but can't find what exactly to use.</p>