• Delaunay三角剖分和Voronoi图的OpenCV示例

import cv2
import numpy as np
import random
# 检查一个点是否在矩形内
def rect_contains(rect, point) :if point[0] < rect[0] :return Falseelif point[1] < rect[1] :return Falseelif point[0] > rect[2] :return Falseelif point[1] > rect[3] :return Falsereturn True
# 绘制一个点
def draw_point(img, p, color ) :cv2.circle( img, p, 2, color, cv2.cv.CV_FILLED, cv2.CV_AA, 0 )
# 绘制 delaunay 三角剖分
def draw_delaunay(img, subdiv, delaunay_color ) :triangleList = subdiv.getTriangleList();size = img.shaper = (0, 0, size[1], size[0])for t in triangleList :pt1 = (t[0], t[1])pt2 = (t[2], t[3])pt3 = (t[4], t[5])if rect_contains(r, pt1) and rect_contains(r, pt2) and rect_contains(r, pt3) :cv2.line(img, pt1, pt2, delaunay_color, 1, cv2.CV_AA, 0)cv2.line(img, pt2, pt3, delaunay_color, 1, cv2.CV_AA, 0)cv2.line(img, pt3, pt1, delaunay_color, 1, cv2.CV_AA, 0)
# 绘制 voronoi 图
def draw_voronoi(img, subdiv) :( facets, centers) = subdiv.getVoronoiFacetList([])for i in xrange(0,len(facets)) :ifacet_arr = []for f in facets :ifacet_arr.append(f)ifacet = np.array(ifacet_arr, np.int)color = (random.randint(0, 255), random.randint(0, 255), random.randint(0, 255))cv2.fillConvexPoly(img, ifacet, color, cv2.CV_AA, 0);ifacets = np.array([ifacet])cv2.polylines(img, ifacets, True, (0, 0, 0), 1, cv2.CV_AA, 0)cv2.circle(img, (centers[0], centers[1]), 3, (0, 0, 0), cv2.cv.CV_FILLED, cv2.CV_AA, 0)
if __name__ == '__main__':win_delaunay = "Delaunay Triangulation"win_voronoi = "Voronoi Diagram"# 当绘制三角形剖分时打开动画画板animate = True# 定义绘制颜色delaunay_color = (255,255,255)points_color = (0, 0, 255)img = cv2.imread("image.jpg");img_orig = img.copy();# 创建用于Subdiv2D 的矩形size = img.shaperect = (0, 0, size[1], size[0])# 创建Subdiv2D 实例subdiv = cv2.Subdiv2D(rect);points = [];# 从 text 文件中读取点with open("points.txt") as file :for line in file :x, y = line.split()points.append((int(x), int(y)))# 将点依次插入subdiv中for p in points :subdiv.insert(p)# 展示动画画板if animate :img_copy = img_orig.copy()draw_delaunay( img_copy, subdiv, (255, 255, 255) );cv2.imshow(win_delaunay, img_copy)cv2.waitKey(100)# 绘制delaunay 三角剖分draw_delaunay( img, subdiv, (255, 255, 255) );for p in points :draw_point(img, p, (0,0,255))# 为Voronoi 图分配空间img_voronoi = np.zeros(img.shape, dtype = img.dtype)# 绘制 Voronoi 图draw_voronoi(img_voronoi,subdiv)cv2.imshow(win_delaunay,img)cv2.imshow(win_voronoi,img_voronoi)cv2.waitKey(0)

得到的结果就是和图1的中间图和右图一样，如果想要看Dlaunay三角剖分的动态过程可以访问这里，或者自己运行上述的代码

openCV【实践系列】5——使用OpenCV进行Delaunay三角剖分
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(出处: 易学智能)