title: How can I do these image processing tasks using OpenGL ES 2.0 shaders?
body: <p>How can I perform the following image processing tasks using OpenGL ES 2.0 shaders?</p>
  
  <ul>
  <li>Colorspace transform ( RGB/YUV/HSL/Lab ) </li>
  <li>Swirling of the image </li>
  <li>Converting to a sketch</li>
  <li>Converting to an oil painting</li>
  </ul>