title: Is ther a way to get 16bit image from opencv videocapture
body: <p>If one camera support 16bit gray image, how to get 16bit image via opencv videocapture class? </p>
  
  <p>Can we do this with by cam.set CV2 CAP_PROP_FORMAT properties? 
  If yes, how to set this properties? </p>
  
  <p>env:
  windows 10 </p>
  
  <p>opencv3.1 python binding </p>
  
  <p>python 3.6.3 </p>
  
  <p>webcam: purethermal with raw 16bit data feeding</p>