Image transforming recipes in Pillow


Martin McBride, 2020-10-18
Tags image processing recipes
Categories pillow
In Python libraries

These ImageOps functions provide methods to transform images.

Each function accepts an input image and returns a transformed image.

flip

flip flips and image vertically:

The code to do this is:

im = Image.open('carousel-small.jpg')
im = ImageOps.flip(im)
im.save('imageops-flip.jpg')

mirror

mirror flips and image horizontally:

The code to do this is:

im = Image.open('carousel-small.jpg')
im = ImageOps.mirror(im)
im.save('imageops-mirror.jpg')

exif-transpose

EXIF is a special type of metadata that can be attached to an image, usually by a camera. It gives details of how the image was obtained (camera model, exposure settings, time and location etc). One setting is the Orientation tag, which typically indicates if the shot was taken in landscape view, or with the camera turned on its side in portrait view.

A typical problem with camera images is portrait mode is that, when they are opened on a computer, they are in landsacpe view (with the subject rotated by 90 degrees).

exif-transpose reads the Orientation tag (if it is present), and rotates the image so that it appears in the correct orientation:

im = Image.open('carousel-small.jpg')
im = ImageOps.exif_transpose(im)
im.save('imageops-exif_transpose.jpg')

If there is no tag present, a copy of the original image is returned.

If this function is applied to a set of images, it will automatically rotate just the images that need rotating.

If you found this article useful, you might be interested in the book Computer Graphics in Python or other books by the same author.