Convert image format using Python

By annak

There’s plenty of image editing software out there, most notably Photoshop - but did you know you can also edit images using Python? While Pillow, the Python library used in this tutorial, won’t replace Photoshop, it does help you to perform certain actions faster - and completely free.

In this introductory tutorial I’ll show you how to convert image format using Pillow library. You can then build on that knowledge to progress to the more advanced concepts, such as Image filters.

I’m using Python version 3.

Tip! Some basic Python knowldege required!

Install Pillow

First, we need to prepare our paints and brushes, in our case it means installing the Pillow library.

In your terminal type:

pip install Pillow

Convert image format

Converting the image format in the Pillow library is quick and easy. In this example I’ll show you how to convert a JPEG image to a PNG.

You can also use Pillow to convert to and from other popular image formats such as:

  • BMP
  • GIF
  • EPS
  • TIFF

Check out the docs for the full list of supported formats.

  1. In your Python file, import Image from the Pillow library. The Image module contains a class of the same name.
from PIL import Image
  1. Create an Image object and call the open method on it. Make sure that you add the correct path for the image location - my image is in the same folder as my Python file, so I don’t need to add it.
img = Image.open('some-pic.jpg')
  1. Save as a png image: specify the file name and the extention (format) to save the image in the same folder. You can also save the image in a different location by adding the file path.
im.save('converted-pic.png')

The resulting Python code:

import Image

img = Image.open('some-pic.jpg')
im.save('converted-pic.png')