title: Load 8bit uint8_t as uint32_t?
body: <p>my image processing project works with grayscale images. I have ARM Cortex-A8 processor platform. I want to make use of the NEON.</p>
  
  <p>I have a grayscale image( consider the example below) and in my alogorithm, I have to add only the columns.</p>
  
  <p>How can I load <strong>four 8-bit pixel values</strong> in parallel, which are <strong>uint8_t</strong>, as <strong>four uint32_t</strong> into one of the 128-bit NEON registers? What intrinsic do I have to use to do this?</p>
  
  <p>I mean:</p>
  
  <p><img src="https://i.stack.imgur.com/cf1tr.jpg" alt="alt text"></p>
  
  <p>I must load them as 32 bits because if you look carefully, the moment I do 255 + 255 is 512, which can't be held in a 8-bit register.</p>
  
  <p>e.g.</p>
  
  <pre><code>255 255 255 255 ......... (640 pixels)
  255 255 255 255
  255 255 255 255
  255 255 255 255
  .
  .
  .
  .
  .
  (480 pixels) 
  </code></pre>