How to Rotate Image in Python: Simple Guide with Examples

To rotate an image in Python, use the Pillow library's Image.rotate(angle) method, where angle is the degrees to rotate. This method returns a new rotated image without changing the original.

Syntax

The basic syntax to rotate an image using Pillow is:

• Image.rotate(angle, resample=0, expand=0, center=None, translate=None, fillcolor=None)

Explanation:

• angle: Degrees to rotate the image counter-clockwise.
• resample: Optional, controls quality of rotation (e.g., Image.BICUBIC).
• expand: Optional, if True, expands output image to fit the whole rotated image.
• center: Optional, tuple to set rotation center.
• translate: Optional, tuple to move the image after rotation.
• fillcolor: Optional, color to fill empty areas after rotation.

python

rotated_image = original_image.rotate(angle, resample=Image.BICUBIC, expand=True)

Example

This example shows how to open an image, rotate it 45 degrees, and save the rotated image.

python

from PIL import Image

# Open an image file
original_image = Image.open('example.jpg')

# Rotate the image 45 degrees counter-clockwise and expand canvas
rotated_image = original_image.rotate(45, expand=True)

# Save the rotated image
rotated_image.save('rotated_example.jpg')

print('Image rotated and saved successfully.')

Output

Image rotated and saved successfully.

Common Pitfalls

Common mistakes when rotating images include:

• Not using expand=True, which can crop the rotated image.
• Forgetting to save or display the rotated image, since rotate() returns a new image.
• Using the wrong angle direction (rotation is counter-clockwise).

python

from PIL import Image

# Wrong: This will crop the rotated image
rotated_wrong = original_image.rotate(45)
rotated_wrong.save('cropped.jpg')

# Right: Use expand=True to keep full image
rotated_right = original_image.rotate(45, expand=True)
rotated_right.save('full_rotated.jpg')

Quick Reference

Tips for rotating images with Pillow:

• Use expand=True to avoid cropping.
• Use resample=Image.BICUBIC for smoother rotation.
• Rotation angle is in degrees counter-clockwise.
• Remember to save or display the rotated image.

Key Takeaways

Use Pillow's Image.rotate(angle, expand=True) to rotate images without cropping.

Rotation angle is counter-clockwise in degrees.

Always save or display the rotated image since rotate() returns a new image.

Use resample options like Image.BICUBIC for better quality.

expand=True adjusts the canvas size to fit the rotated image fully.