title: Stereo system - Get 3d position usind OpenCv
body: <p>I have a stereo system with 2 cameras. I calibrated these cameras. I try to calculate distance between each fingertip.On left image, I find fingertips using convex hull. I calculate epipoolar line for these points.I draw epipolar lines on right image. How can I calculate 3d position each fingertips? I used c++ and opencv.</p>
  
  <p>There are 5 window below image. They are : 
  right image,
  left image, 
  find fingertips using convex hull on right image, 
  draw epipolar lines on left image, 
  find correspondences points on left images</p>
  
  <p><img src="https://i.stack.imgur.com/WWit6.png" alt="enter image description here"></p>
  
  <p>My .yml file is below after stereo calibration</p>
  
  <pre><code>%YAML:1.0
  CM1: !!opencv-matrix
   rows: 3
   cols: 3
   dt: d
   data: [ 1.4947330489959640e+02, 0., 8.5026435902438408e+01, 0.,
     1.7045159164506524e+02, 6.8513237416979280e+01, 0., 0., 1. ]
  CM2: !!opencv-matrix
  rows: 3
  cols: 3
  dt: d
  data: [ 1.4947330489959640e+02, 0., 7.6063817190941975e+01, 0.,
     1.7045159164506524e+02, 6.9869364400956655e+01, 0., 0., 1. ]
  D1: !!opencv-matrix
  rows: 1
  cols: 5
  dt: d
  data: [ 4.6664660489275862e+00, -9.5605452982913761e+01, 0., 0.,
     4.4411083031870203e+02 ]
  D2: !!opencv-matrix
  rows: 1
  cols: 5
  dt: d
  data: [ -2.6243438145377401e-01, 3.1158182596121313e+00, 0., 0.,
     -6.9555261934841601e+00 ]
  R: !!opencv-matrix
  rows: 3
  cols: 3
  dt: d
  data: [ -9.9870707407742809e-01, 5.0820157566619700e-02,
     1.2213814337059467e-03, -4.6584627039081256e-02,
     -9.2456021193091820e-01, 3.7817758664136281e-01,
     2.0348285218473684e-02, 3.7763173343769685e-01,
     9.2573226215224258e-01 ]
  T: !!opencv-matrix
  rows: 3
  cols: 1
  dt: d
  data: [ -5.0257191774306198e-01, -5.1791340062890008e+00,
     -1.7104054803114692e+00 ]
  E: !!opencv-matrix
  rows: 3
  cols: 3
  dt: d
  data: [ -1.8506509733057530e-01, -3.5371782058656147e+00,
     -4.1476544229091719e+00, 1.7184205294528965e+00,
     1.0286402846218139e-01, 4.6315798080871423e-01,
     -5.1490256443274198e+00, 7.2786240503729882e-01,
     -1.8373573684783620e-01 ]
   F: !!opencv-matrix
    rows: 3
   cols: 3
   dt: d
   data: [ -2.0635586643392613e-06, -3.4586914187982223e-05,
     -4.3677532717492718e-03, 1.6802903312164187e-05,
     8.8202517402136951e-07, -8.1218529743132760e-04,
     -9.5988974549000728e-03, 3.6330053228360980e-03, 1. ]
  </code></pre>