In [1]:

    

import cv2
import numpy as np

import pprint


    

In [2]:

    

w = h = 360


    

In [3]:

    

n = 6
np.random.seed(0)
pts = np.random.randint(0, w, (n, 2))


    

In [4]:

    

print(pts)


    

    




[[172  47]
 [117 192]
 [323 251]
 [195 359]
 [  9 211]
 [277 242]]

In [5]:

    

print(type(pts))


    

    




<class 'numpy.ndarray'>

In [6]:

    

print(pts.shape)


    

    




(6, 2)

In [7]:

    

img = np.zeros((w, h, 3), np.uint8)


    

In [8]:

    

for p in pts:
    cv2.drawMarker(img, tuple(p), (255, 255, 255), thickness=2)


    

In [9]:

    

cv2.imwrite('data/dst/opencv_random_pts.png', img)


    

    
Out[9]:





True

In [10]:

    

rect = (0, 0, w, h)


    

In [11]:

    

subdiv = cv2.Subdiv2D(rect)


    

In [12]:

    

for p in pts:
    subdiv.insert((p[0], p[1]))


    

In [13]:

    

triangles = subdiv.getTriangleList()


    

In [14]:

    

print(triangles)


    

    




[[ 1080.     0.     0.  1080.   323.   251.]
 [    0.  1080.  1080.     0. -1080. -1080.]
 [    0.  1080. -1080. -1080.     9.   211.]
 [-1080. -1080.  1080.     0.   172.    47.]
 [  172.    47.  1080.     0.   323.   251.]
 [  172.    47.   323.   251.   277.   242.]
 [-1080. -1080.   172.    47.     9.   211.]
 [  172.    47.   117.   192.     9.   211.]
 [  117.   192.   172.    47.   277.   242.]
 [    9.   211.   195.   359.     0.  1080.]
 [  195.   359.     9.   211.   117.   192.]
 [  323.   251.     0.  1080.   195.   359.]
 [  195.   359.   117.   192.   277.   242.]
 [  323.   251.   195.   359.   277.   242.]]

In [15]:

    

pols = triangles.reshape(-1, 3, 2)


    

In [16]:

    

print(pols)


    

    




[[[ 1080.     0.]
  [    0.  1080.]
  [  323.   251.]]

 [[    0.  1080.]
  [ 1080.     0.]
  [-1080. -1080.]]

 [[    0.  1080.]
  [-1080. -1080.]
  [    9.   211.]]

 [[-1080. -1080.]
  [ 1080.     0.]
  [  172.    47.]]

 [[  172.    47.]
  [ 1080.     0.]
  [  323.   251.]]

 [[  172.    47.]
  [  323.   251.]
  [  277.   242.]]

 [[-1080. -1080.]
  [  172.    47.]
  [    9.   211.]]

 [[  172.    47.]
  [  117.   192.]
  [    9.   211.]]

 [[  117.   192.]
  [  172.    47.]
  [  277.   242.]]

 [[    9.   211.]
  [  195.   359.]
  [    0.  1080.]]

 [[  195.   359.]
  [    9.   211.]
  [  117.   192.]]

 [[  323.   251.]
  [    0.  1080.]
  [  195.   359.]]

 [[  195.   359.]
  [  117.   192.]
  [  277.   242.]]

 [[  323.   251.]
  [  195.   359.]
  [  277.   242.]]]

In [17]:

    

img_draw = img.copy()

cv2.polylines(img_draw, pols.astype(int), True, (0, 0, 255), thickness=2)

cv2.imwrite('data/dst/opencv_delaunay.png', img_draw)


    

    
Out[17]:





True

In [18]:

    

print(np.all(pols[:, :, 0] < w, axis=1))


    

    




[False False  True False False  True  True  True  True  True  True  True
  True  True]

In [19]:

    

pols_inner = pols[np.all(pols[:, :, 0] < w, axis=1) &
                  np.all(pols[:, :, 0] > 0, axis=1) &
                  np.all(pols[:, :, 1] < h, axis=1) &
                  np.all(pols[:, :, 1] > 0, axis=1)]


    

In [20]:

    

print(pols_inner)


    

    




[[[172.  47.]
  [323. 251.]
  [277. 242.]]

 [[172.  47.]
  [117. 192.]
  [  9. 211.]]

 [[117. 192.]
  [172.  47.]
  [277. 242.]]

 [[195. 359.]
  [  9. 211.]
  [117. 192.]]

 [[195. 359.]
  [117. 192.]
  [277. 242.]]

 [[323. 251.]
  [195. 359.]
  [277. 242.]]]

In [21]:

    

img_draw = img.copy()

cv2.polylines(img_draw, pols_inner.astype(int), True, (0, 0, 255), thickness=2)

cv2.imwrite('data/dst/opencv_delaunay_inner.png', img_draw)


    

    
Out[21]:





True

In [22]:

    

facets, centers = subdiv.getVoronoiFacetList([])


    

In [23]:

    

pprint.pprint(facets)


    

    




[array([[  331.1972 ,    87.04766],
       [  218.6763 ,   147.63583],
       [   41.71519,    80.51266],
       [ -503.5626 ,  -461.44025],
       [  540.8418 , -1621.6836 ],
       [  618.2897 ,  -125.45706]], dtype=float32),
 array([[218.6763 , 147.63583],
       [182.60144, 263.07538],
       [ 82.09151, 310.02014],
       [ 41.71519,  80.51266]], dtype=float32),
 array([[ 282.99118,  333.434  ],
       [ 331.1972 ,   87.04766],
       [ 618.2897 , -125.45706],
       [ 987.2233 ,  987.2233 ],
       [ 759.8912 ,  898.6488 ]], dtype=float32),
 array([[ 182.60144,  263.07538],
       [ 282.99118,  333.434  ],
       [ 759.8912 ,  898.6488 ],
       [-183.30182,  643.555  ],
       [  82.09151,  310.02014]], dtype=float32),
 array([[   82.09151,   310.02014],
       [ -183.30182,   643.555  ],
       [-1793.752  ,   626.876  ],
       [ -503.5626 ,  -461.44025],
       [   41.71519,    80.51266]], dtype=float32),
 array([[218.6763 , 147.63583],
       [331.1972 ,  87.04766],
       [282.99118, 333.434  ],
       [182.60144, 263.07538]], dtype=float32)]

In [24]:

    

print(centers)


    

    




[[172.  47.]
 [117. 192.]
 [323. 251.]
 [195. 359.]
 [  9. 211.]
 [277. 242.]]

In [25]:

    

img_draw = img.copy()

cv2.polylines(img_draw, [f.astype(int) for f in facets], True, (255, 255, 255), thickness=2)

cv2.imwrite('data/dst/opencv_voronoi.png', img_draw)


    

    
Out[25]:





True

In [26]:

    

img_draw = img.copy()

step = int(255 / len(facets))

for i, p in enumerate(f.astype(int) for f in facets):
    cv2.fillPoly(img_draw, [p], (step * i, step * i, step * i))

cv2.imwrite('data/dst/opencv_voronoi_fill.png', img_draw)


    

    
Out[26]:





True

In [27]:

    

img_draw = img.copy()

step = int(255 / len(facets))

for i, p in enumerate(f.astype(int) for f in facets):
    cv2.fillPoly(img_draw, [p], (step * i, step * i, step * i))

cv2.polylines(img_draw, pols_inner.astype(int), True, (0, 0, 255), thickness=2)

for c in centers:
    cv2.drawMarker(img_draw, tuple(c), (255, 255, 255), thickness=2)

cv2.imwrite('data/dst/opencv_delaunay_voronoi.png', img_draw)


    

    
Out[27]:





True