Change image resolution using Pillow in Python

Prerequisites: Python pillow

PIL is the Python Imaging Library which provides the python interpreter with an in-depth file format support, an efficient internal representation, and fairly powerful image processing capabilities. Changing the resolution of an image simply means reducing or increasing the number of pixels in an image, without changing its dimensions or any other factor. In this article, we are going to learn the methods how to change the quality/Resolution of an image with the help of python PIL(pillow) Library.

Changing Image Resolution

Using quality Parameter:

The image quality is a scale to measure and store the resolution of an image. It lies in the range of 0 to 100 where 95 is considered as best because 100 disables some portions of jpeg compression algorithm that results very large files. While on the other hand the gain in image quality or resolution is also insignificant from 95 to 100. The functionality can be achieved by the following steps:

1. Import the Images module from pillow.
2. Open the image using .open( ) method by specifying the image path.
3. The image_file.save() method have a parameter named quality, that specifies the resolution of an image in a 1-100 scale, where 95 is considered as the optimal quality.

Program:

Python3

# Import the Images module from pillow
from PIL import Image

# Open the image by specifying the image path.
image_path = "image_name.jpeg"
image_file = Image.open(image_path)

# the default
image_file.save("image_name.jpg", quality=95)

# Changing the image resolution using quality parameter
# Example-1
image_file.save("image_name2.jpg", quality=25)

# Example-2
image_file.save("image_name3.jpg", quality=1)

Original Image:

Output:

Default/High resolution (Quality=95):

Medium Resolution (Quality=25):

Low Resolution (Quality=1):