title: Subtracting two images using NEON
body: <p>I'm trying to subtract two images(grayscaled) by using Neon intrinsics as an exercise, I don't know what is the best way to subtract two vectors using the C intrinsics. </p>
  
  <pre><code>void subtractTwoImagesNeonOnePass( uint8_t *src, uint8_t*dest, uint8_t*result, int srcWidth)
  {
  
  
      for (int i = 0; i&lt;srcWidth; i++)
      {
          // load 8 pixels
          uint8x8x3_t srcPixels  = vld3_u8 (src);
          uint8x8x3_t dstPixels  = vld3_u8 (src);
          // subtract them
          uint8x8x3_t subPixels =  vsub_u8(srcPixels, dstPixels);
          // store the result
          vst1_u8 (result, subPixels);
          // move 8 pixels
          src+=8;
          dest+=8;
          result+=8;
  
      }
  
  }
  </code></pre>