title: What is the impact of different JPEG's type on different JPEG decoding sub-process.?
body: <p>As we all know, the JPEG decoding process is shown in the following:</p>
  
  <ul>
  <li>VLD - Variable length decoding,</li>
  <li>ZZ - Zigzag scan,</li>
  <li>DQ - Dequantization,</li>
  <li>IDCT - Inverse discrete cosine transform,</li>
  <li>Color conversion (YUV to RGB) and reorder.</li>
  </ul>
  
  <p>My question is: for different characters of different JPEG images, which of the above decoding process will take more time? </p>
  
  <p>For example: <img src="https://i.stack.imgur.com/g4ryV.jpg" alt=""></p>
  
  <p>For decoding this type of image with noise, which of the above Five process will take relatively more time?</p>
  
  <p>Another example: 
  <img src="https://i.stack.imgur.com/Eqcj2.jpg" alt=""></p>
  
  <p>For two same images wit different quality, which one of the above Five processes will take more time when decoding a image with higher quality? </p>