Python PIL | RankFilter() method

PIL is the Python Imaging Library which provides the python interpreter with image editing capabilities. The ImageFilter module contains definitions for a pre-defined set of filters, which can be used with the Image.filter() method.

PIL.ImageFilter.RankFilter() creates a rank filter. The rank filter sorts all pixels in a window of the given size, and returns the rank’th value.

Syntax: PIL.ImageFilter.RankFilter(size, rank)

Parameters:
size: The kernel size, in pixels.
rank: What pixel value to pick. Use 0 for a min filter, size * size / 2 for a median filter, size * size – 1 for a max filter, etc.

Note: value for rank must be integer type.

Image used:

# Importing Image and ImageFilter module from PIL package
from PIL import Image, ImageFilter

# creating a image object
im1 = Image.open(r"C:\Users\sadow984\Desktop\download2.JPG")

# applying the rank filter
im2 = im1.filter(ImageFilter.RankFilter(size = 3, rank = 0))

im2.show()

Output:

# Importing Image and ImageFilter module from PIL package
from PIL import Image, ImageFilter

# creating a image object
im1 = Image.open(r"C:\Users\sadow984\Desktop\download2.JPG")

# applying the rank filter
im2 = im1.filter(ImageFilter.RankFilter(size = 3, rank = 3 * 3-1))

im2.show()

Output:

# Importing Image and ImageFilter module from PIL package
from PIL import Image, ImageFilter

# creating a image object
im1 = Image.open(r"C:\Users\sadow984\Desktop\download2.JPG")

# applying the rank filter
im2 = im1.filter(ImageFilter.RankFilter(size = 3, rank = (3 * 3)//2))

im2.show()

Output: