# 3 d model points. 
MODEL_POINTS_68=np. Array ([
[53.30021857, 15.27635071, 60.43970857], 
[52.85842643, 1.810875, 59.18390214], 
[51.25744357, 11.67454214, 58.42188571], 
[48.626315, 24.63487214, 57.20655286], 
[43.58355, 36.41352214, 53.98811286], 
[35.42554, 46.354015, 48.35620143], 
[25.24848857, 54.04395214, 39.57465214], 
[13.64442429, 59.62245214, 28.96935357], 
[0.80573857, 61.05416214, 25.76168714], 
[11.60732, 59.40927786, 30.09232929], 
[22.44441643, 53.81683, 40.08901643], 
[32.24683929, 46.23280714, 48.37045], 
[40.083355, 36.30976214, 53.26906357], 
[45.11549929, 24.19315786, 55.59597786], 
[47.84661071, 11.00381857, 56.59250643], 
[49.47115857, 2.32260857, 57.92187643], 
[50.10645643, 15.67903571, 60.06320429], 
[44.53299214, 29.24790071, 36.57320143], 
[37.510265, 35.96803857, 31.583005], 
[27.87970214, 38.27258143, 26.70722214], 
[18.03538357, 37.58489857, 21.67254214], 
[9.18749714, 34.48015571, 17.84333], 
[7.73560929, 34.98320857, 17.78346857], 
[17.05676643, 38.20546071, 21.16640143], 
[26.50843214, 38.83083714, 25.66079071], 
[35.68873143, 36.34843286, 30.21249643], 
[42.01933429, 29.83979571, 34.68843286], 
[0.40917357, 24.128035, 16.83373214], 
[0.30141, 16.12798571, 11.28371929], 
[0.16755643, 8.23575357, 5.47430286], 
. [0, 0, 0.], 
[10.55176571, 1.85589643, 14.38000214], 
[5.12874214, 3.39399214, 16.81191714], 
[0.39708571, 4.68778571, 18.53174857], 
[5.90892786, 3.32928929, 16.92552929], 
[10.86739357, 1.88789, 14.89868357], 
[32.89092143, 26.76529357, 5.027135], 
[26.91049143, 30.52179286, 2.15801214], 
[19.91704, 30.50822643, 0.96687786], 
[14.03447714, 26.25338714, 0.07934857], 
[20.194975, 25.09606643, 0.105195], 
[27.20172714, 24.94217357, 1.05472286], 
[13.76133429, 26.45164714, 0.47553286], 
[19.92442214, 30.95888929, 0.1769], 
[26.74109214, 30.79344429, 1.21173929], 
[32.26486071, 27.20465357, 3.49583071], 
[27.28318143, 25.38001714, 0.202115], 
[20.54642071, 25.34592071, 0.837625], 
[20.65447643, 20.43765429, 1.60022143], 
[12.52371, 15.83727643, 11.38166786], 
[4.77470714, 13.59217929, 16.15096786], 
[0.27214357, 14.80079857, 16.96316929], 
[5.98245929, 13.59675714, 16.22999643], 
[13.48329857, 15.99579214, 11.150485], 
[20.56743714, 20.05708857, 2.29813786], 
[13.61255286, 25.92732, 10.70571214], 
[6.39741071, 28.31041071, 16.110175], 
[0.272535, 28.85403357, 16.85116143], 
[5.30635357, 28.454575, 16.00436143], 
[12.97188143, 26.19849929, 10.80136214], 
[17.41249286, 20.48412214, 3.41834571], 
[4.92688071, 18.19712571, 14.92410143], 
[0.24333071, 18.58162071, 15.87177071], 
[6.03194429, 18.09014143, 15.01822857], 
[17.48176643, 20.23072, 4.08055429], 
[6.03511857, 21.85444, 14.76534929], 
[0.14665857, 22.43481286, 15.64547857], 
[5.14161857, 22.03205429, 14.52001571]], dtype=float) 

The class PoseEstimator: 
"" "Estimate head pose "according to the differentiated bi-facial the landmarks" "" 

Def __init__ (self, img_size=(192, 256)) : 
Self. Size=img_size 
Self. Landmarks_general_68=MODEL_POINTS_68 
# self. Focal_length=962 
Self. Focal_length=self. Size [1] 
Self. Camera_center=(self. Size [1]/2, the self. The size [0]/2) 
Self. Camera_matrix=np. Array (
[[self. Focal_length, 0, self camera_center [0]], 
[0, self focal_length, self camera_center [1]], 
[0, 0, 1]], dtype=float) 

# Assuming no lens distortion 
Self. Dist_coeefs=np. Zeros ((4, 1)) 

# Rotation vector and translation vector; The original code to set the initial value to it, don't know how to come? 
Self. R_vec=np. Array ([[0], [0], [0]], dtype=float) 
Self. T_vec=np. Array ([[0], [0], [0]], dtype=float) 


Def get_euler_angle (self, rotation_vector) : 
# calc rotation angles 
Theta=cv2. Norm (rotation_vector, cv2 NORM_L2) 

# the transform to quaterniond 
W=math. Cos (theta/2) 
X=math. Sin (theta/2) * rotation_vector [0] [0]/theta 
Y=math. Sin (theta/2) * rotation_vector [1] [0]/theta 
Z=math. Sin (theta/2) * rotation_vector [2] [0]/theta 

# pitch (x axis rotation) 
T0=2.0 * (x + y w * * z) 
T1=1.0-2.0 * * * 2 * * 2 (x + y) 
Pitch=math.h atan2 (t0, t1) 

# yaw (y - axis rotation) 
T2=2.0 * * * x y z (w) 
If t2 & gt; 1.0: 
T2=1.0 
If t2 & lt; - 1.0: 
T2=1.0 
Yaw=math.h asin (t2) 

# roll (z - axis rotation) 
T3=2.0 * (w * z + x * y) 
T4=1.0-2.0 * * * * * 2 + z (y 2) 
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