title: CUDA NPP - image reduction - find sum/average of all image pixels
body: <p>I have an 8-bit unsigned char image, which is grayscale (values between 0-255), and I want to use the NPP CUDA library documentation, which provides some functions such as <code>nppiSum_8u64s_C1R</code>, to find the sum and average over all the pixels. </p>
  
  <p>But, I don't know what <code>oSizeROI</code> stands for in the <code>nppiSum_8u64s_C1R</code> function? Should I just input my image dimensions <code>w256 x h1024</code> here? </p>
  
  <p>image_statistics__functions.html#gad5ca4eb684d5414e6026564ea63a1437">http://graphics.im.ntu.edu.tw/~bossliaw/nvCuda_doxygen/html/group_<em>image</em>_statistics__functions.html#gad5ca4eb684d5414e6026564ea63a1437</p>