How to Concatenate image using Pillow in Python ?

Last Updated : 07 Apr, 2021

Concatenate image means joining of two images. We can merge any image whether it has different pixels, different image formats namely, ‘jpeg’, ‘png’, ‘gif’, ‘tiff’, etc. In python, we can join two images using the Python image library also known as the pillow library. In this article, we will see how the concatenation of images is done.

Concatenation of images can be done in two ways :

Horizontal
Vertical

Concatenating images horizontally

Approach:

Import module
Open the images
Resize the image using Resize() function. Both the resize images should be of the same width and height so that their aspect ratio is intact and can be pasted into the new background image.
To create a new image it has a new() function which has 3 parameters (“mode”,(size),color)
Paste the image to new image using paste()

Program:

Python3

# library 
from PIL import Image 
import matplotlib.pyplot as plt 
  
# opening up of images 
img = Image.open("logo.png") 
img1 = Image.open("logo2.png") 
img.size 
img1.size 
img_size = img.resize((250, 90)) 
img1_size = img1.resize((250, 90)) 
  
# creating a new image and pasting  
# the images 
img2 = Image.new("RGB", (500, 90), "white") 
  
# pasting the first image (image_name, 
# (position)) 
img2.paste(img_size, (0, 0)) 
  
# pasting the second image (image_name, 
# (position)) 
img2.paste(img1_size, (250, 0)) 
  
plt.imshow(img2) 

Output :

Concatenating images vertically

The whole code is the same as horizontal but the only change is that in horizontal we double the width and the height is same but in vertical we make the size of width same, but we double the height.

Approach:

Import the libraries for image processing.
Use Image.open() to open the library.
Use img.size to know the size of the image.
Use img.resize((width,height)) to resize the image.
Both the images should be of same size.
Create a new image using new() and pass the 3 parameters”mode”,size,”color”).
Size in new image should be (width, 2*height).
After the creation of new image, paste the first image by using paste() and pass the parameter(img_resize,(position)) #position(0,0)
After pasting the first image, paste the second image using paste and pass the parameter(img1_reszie, (position)). In position, width would be the same but the height would be the last position of the first image’s height. . #position=(0,180)
Use plt.imshow(img2) to show the concatenate of images.

Program:

Python3

# library 
from PIL import Image 
import matplotlib.pyplot as plt 
  
  
# opening up of images 
img = Image.open("logo.png") 
img1 = Image.open("logo2.png") 
img.size 
img1.size 
img_size = img.resize((250, 90)) 
img1_size = img1.resize((250, 90)) 
  
# creating a new image and pasting the  
# images 
img2 = Image.new("RGB", (250, 180), "white") 
  
# pasting the first image (image_name, 
# (position)) 
img2.paste(img_size, (0, 0)) 
  
# pasting the second image (image_name, 
# (position)) 
img2.paste(img1_size, (0, 90) 
  
plt.imshow(img2) 