Skip to content
Related Articles

Related Articles

Improve Article
Python OpenCV | cv2.copyMakeBorder() method
  • Last Updated : 18 Oct, 2019


OpenCV-Python is a library of Python bindings designed to solve computer vision problems. cv2.copyMakeBorder() method is used to create a border around the image like a photo frame.

Syntax: cv2.copyMakeBorder(src, top, bottom, left, right, borderType, value)

Parameters:
src: It is the source image.
top: It is the border width in number of pixels in top direction.
bottom: It is the border width in number of pixels in bottom direction.
left: It is the border width in number of pixels in left direction.
right: It is the border width in number of pixels in right direction.
borderType: It depicts what kind of border to be added. It is defined by flags like cv2.BORDER_CONSTANT, cv2.BORDER_REFLECT, etc
value: It is an optional parameter which depicts color of border if border type is cv2.BORDER_CONSTANT.

Return Value: It returns an image.

The borderType flags are described below:



cv2.BORDER_CONSTANT: It adds a constant colored border. The value should be given as next argument.
cv2.BORDER_REFLECT: The border will be mirror reflection of the border elements. Suppose, if image contains letters “abcdefg” then output will be “gfedcba|abcdefg|gfedcba“.
cv2.BORDER_REFLECT_101 or cv2.BORDER_DEFAULT: It does the same works as cv2.BORDER_REFLECT but with slight change. Suppose, if image contains letters “abcdefgh” then output will be “gfedcb|abcdefgh|gfedcba“.
cv2.BORDER_REPLICATE: It replicates the last element. Suppose, if image contains letters “abcdefgh” then output will be “aaaaa|abcdefgh|hhhhh“.

Image used for all the below examples:

Example #1:




# Python program to explain cv2.copyMakeBorder() 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'
  
# Using cv2.copyMakeBorder() method
image = cv2.copyMakeBorder(image, 10, 10, 10, 10, cv2.BORDER_CONSTANT)
  
# Displaying the image 
cv2.imshow(window_name, image)

Output:

Example #2:




# Python program to explain cv2.copyMakeBorder() 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'
  
# Using cv2.copyMakeBorder() method
image = cv2.copyMakeBorder(image, 100, 100, 50, 50, cv2.BORDER_REFLECT)
  
# Displaying the image 
cv2.imshow(window_name, image)

Output:

 Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.  

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning – Basic Level Course




My Personal Notes arrow_drop_up
Recommended Articles
Page :