使用 OpenCV函数fillPoly() 绘制填充多边形

OpenCV 的 fillPoly()函数用于在图像上绘制填充的多边形，如矩形、三角形、五边形。此函数接受输入图像和多边形和颜色的端点。

Syntax: cv2.fillpoly(Image,End_Points,Color)

Parameter:

• Image: This is image on which we want draw filled polygon
• End_Points: Points of polygon(for triangle 3 end points, for rectangle 4 end points will be there)
• Color: It specifies the color of polygon

示例 1：画一个三角形

在此示例中，我们将通过将 [160,130]、[350,130]、[250,300] 等 3 个端点提供给 fillPoly()函数来绘制填充多边形三角形。

输入图像：

代码：

Python3

# Import necessary libraries
import cv2
import numpy as np
  
# Read an image
img = cv2.imread("image.png")
  
# Define an array of endpoints of triangle
points = np.array([[160, 130], [350, 130], [250, 300]])
  
# Use fillPoly() function and give input as
# image, end points,color of polygon
# Here color of polygon will blue
cv2.fillPoly(img, pts=[points], color=(255, 0, 0))
  
# Displaying the image
cv2.imshow("Triangle", img)
  
# wait for the user to press any key to 
# exit window
cv2.waitKey(0)
  
# Closing all open windows
cv2.destroyAllWindows()

输出：

示例 2：绘制六边形

在此示例中，我们将通过将 [220,120]、[130,200]、[130,300]、[220,380]、[310,300]、[310,200] 等 6 个端点提供给 fillPoly()函数来绘制一个六边形。

输入：

代码：

Python3

# Import necessary libraries
import cv2
import numpy as np
  
# Read an image
img = cv2.imread("image.png")
  
# Define an array of endpoints of Hexagon
points = np.array([[220, 120], [130, 200], [130, 300],
                   [220, 380], [310, 300], [310, 200]])
  
# Use fillPoly() function and give input as image,
# end points,color of polygon
# Here color of polygon will be green
cv2.fillPoly(img, pts=[points], color=(0, 255, 0))
  
# Displaying the image
cv2.imshow("Hexagon", img)
  
# wait for the user to press any key to 
# exit window
cv2.waitKey(0)
  
# Closing all open windows
cv2.destroyAllWindows()

输出：

示例 3：绘制一个矩形

有时我们需要通过隐藏他们的脸来显示某人的照片。在这种情况下，我们可以使用这个函数来隐藏一个人的脸。

输入：

代码：

Python3

# Import necessary libraries
import cv2
import numpy as np
  
# Read an image
img = cv2.imread("Documents/Person_Image.jpg", 
                 cv2.IMREAD_COLOR)
  
# Define an array of endpoints of Rectangle
points = np.array([[300, 180], [400, 180], 
                   [400, 280], [300, 280]])
  
# Use fillPoly() function and give input as image,
# end points,color of polygon
# Here color of polygon will be red
cv2.fillPoly(img, pts=[points], color=(0, 0, 255))
  
# Displaying the image
cv2.imshow("Rectangle", img)
  
# wait for the user to press any key to exit window
cv2.waitKey(0)
  
# Closing all open windows
cv2.destroyAllWindows()

输出：