Python OpenCV | cv2.circle() 方法

OpenCV-Python是一个Python绑定库，旨在解决计算机视觉问题。 cv2.circle() 方法用于在任何图像上画一个圆。

Syntax: cv2.circle(image, center_coordinates, radius, color, thickness)
Parameters: 
image: It is the image on which circle is to be drawn. 
center_coordinates: It is the center coordinates of circle. The coordinates are represented as tuples of two values i.e. (X coordinate value, Y coordinate value). 
radius: It is the radius of circle. 
color: It is the color of border line of circle to be drawn. For BGR, we pass a tuple. eg: (255, 0, 0) for blue color. 
thickness: It is the thickness of the circle border line in px. Thickness of -1 px will fill the circle shape by the specified color.
Return Value: It returns an image. 
 

用于以下所有示例的图像：

示例 #1：

Python3

# Python program to explain cv2.circle() method
   
# importing cv2
import cv2
   
# path
path = r'C:\Users\Rajnish\Desktop\geeksforgeeks\geeks.png'
   
# Reading an image in default mode
image = cv2.imread(path)
   
# Window name in which image is displayed
window_name = 'Image'
  
# Center coordinates
center_coordinates = (120, 50)
 
# Radius of circle
radius = 20
  
# Blue color in BGR
color = (255, 0, 0)
  
# Line thickness of 2 px
thickness = 2
  
# Using cv2.circle() method
# Draw a circle with blue line borders of thickness of 2 px
image = cv2.circle(image, center_coordinates, radius, color, thickness)
  
# Displaying the image
cv2.imshow(window_name, image)

输出：

示例 #2：
使用 -1 px 的厚度用红色填充圆圈。

Python3

# Python program to explain cv2.circle() method
   
# importing cv2
import cv2
   
# path
path = r'C:\Users\Rajnish\Desktop\geeksforgeeks\geeks.png'
   
# Reading an image in default mode
image = cv2.imread(path)
   
# Window name in which image is displayed
window_name = 'Image'
  
# Center coordinates
center_coordinates = (120, 100)
 
# Radius of circle
radius = 30
  
# Red color in BGR
color = (0, 0, 255)
  
# Line thickness of -1 px
thickness = -1
  
# Using cv2.circle() method
# Draw a circle of red color of thickness -1 px
image = cv2.circle(image, center_coordinates, radius, color, thickness)
  
# Displaying the image
cv2.imshow(window_name, image)

输出：