title: OpenCV Image Mat to 1D CHW(RR...R, GG..G, BB..B) vector
body: <p>Nvidia's cuDNN for deep learning has a rather interesting format for images called CHW. I have a cv::Mat img; that I want to convert to a one-dimensional vector of floats. The problem that I'm having is that the format of the 1D vector for CHW is (RR...R, GG..G,BB..B). </p>
  
  <p>So I'm curious as to how I can extract the channel values for each pixel and order them for this format.</p>