Python Image Processing With Pillow

The Pillow Python Imaging Library is ideal for image processing. Typically, it’s used for archival and batch processing applications. Of course, you’re free to use it for anything else you can think of. You can use the library to:

• Create thumbnails
• Convert between file formats,
• Print images
• Fet a histogram (ideal for automatic contrast enhancement)
• Rotate images
• Apply filters like blur

Installing the image processing package

To install Pillow, which is a fork and continuation of the original Python Imaging Library, use the pip install command:

pip3 install Pillow

After this, you can import the module which is called PIL, or you can import parts of the module with the from PIL import ..... syntax.

Processing images

Pillow offers several filters which become available after importing ImageFilter. For example, to blur an image, use:

from PIL import Image, ImageFilter

im = Image.open("kittens.jpg")
blurred = im.filter(ImageFilter.BLUR)

Other filters include SHARPEN, SMOOTH, and EDGE_ENHANCE. For a complete list of filters, check the reference docs on ImageFilter.

To rotate an image by 180 degrees:

rotated_image = im.rotate(180) 

And finally, to save the results of your hard work:

rotated_image.save("rotated.jpg")

Displaying images

Besides image processing, this library can also be used to display images on the screen. Here’s some example code to display a file called kittens.jpg:

from PIL import Image

im = Image.open("kittens.jpg")
im.show()
print(im.format, im.size, im.mode)
# JPEG (1920, 1357) RGB

In the following animated gif, I demonstrate how to use Pillow right from IPython:

Further reading

The library has much more to offer. To learn everything about Python image processing using Pillow, it’s best to head over to the official tutorial!