How to find edges in Image using Pillow?

Pillow - Find image edges

To find the edges in an image using Pillow library, you can use Image.filter() function with ImageFilter.FIND_EDGES kernel.

Steps to find edges in an image

Follow these steps to find edges in a given image.

1. Import Image, and ImageFilter modules from Pillow library.
2. Read input image using Image.open() function.
3. Call filter() function on the read Image object and pass ImageFilter.FIND_EDGES as argument to the function. The function returns the edges image as PIL.Image.Image object.
4. Save the returned image to required location using Image.save() function.

Syntax of filter() function

The syntax of filter() function from PIL.Image module is

PIL.Image.filter(filter_kernel)

Parameter	Description
filter_kernel	A filter kernel that applies to the given image. To find edge of this image, you can use ImageFilter.FIND_EDGES filter kernel.

Returns

The function returns a PIL.Image.Image object.

Examples

1. Find edges in given image

In the following example, we read an image test_image.jpg, find edges in this image using Image.filter() function, and save the edge image as edges.jpg.

Python Program

from PIL import Image, ImageFilter

# Open the image
image = Image.open("test_image.jpg")
# Find edges of the image
edges = image.filter(ImageFilter.FIND_EDGES)

# Save the resulting image
edges.save("edges.jpg")

Original Image [test_image.jpg]

Resulting Image with FIND_EDGES filter [edges.jpg]

Summary

In this Python Pillow Tutorial, we learned how to find edges in a given image using PIL.Image.filter() function, with the help of examples.