title: Is it possible to determine the yaw, pitch and roll of a face given the locations of the eyes and mouth? (picture included)
body: <p><img src="https://i.imgur.com/9HSC42K.jpg" alt="enter image description here"></p>
  
  <p>Red dots = Left Eye Center (L), Right Eye Center (R), Mouth Center (M)</p>
  
  <p>Purple Line = Line LR</p>
  
  <p>Red Line = Horizontal line intersecting midpoint of L and R</p>
  
  <p>Yellow Line = Vertical Line intersecting LR at M.x</p>
  
  <p>Blue Line(s) = LM and RM</p>
  
  <p>Green Line = Distance between X-Coordinates of L and R</p>
  
  <p>Given this data, is it possible to determine the yaw, pitch and roll of a face?</p>
  
  <p>All I have so far is the roll:</p>
  
  <p>Roll = the angular difference between the left and right eye</p>
  
  <p>Knowing that L, R and M all move relative to each other, it should be possible to calculate yaw and pitch in 2D space right? </p>
  
  <p>My first thought was that yaw could be calculated as a ratio of the X coordinate of M relative to the distance of the x-coords of LR (The green line)</p>
  
  <p>Any thoughts?</p>
  
  <p>note: I'm using opencv</p>