Python Pillow - ImageOps.grayscale() Function

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The PIL.ImageOps.grayscale function is used to convert an image to grayscale. Grayscale is a single-channel representation of an image where each pixel's intensity is represented by a single value, typically ranging from 0 (black) to 255 (white).

Syntax

Following is the syntax of the function −

PIL.ImageOps.grayscale(image)

Parameters

Here are the details of this function parameters −

• image − The image is to be converted to grayscale.

Return Value

The function returns a new image object where the input image has been converted to grayscale.

Examples

Example 1

In this example, ImageOps.grayscale() function is used to convert a color image to grayscale.

from PIL import Image, ImageOps

# Open an image file
color_image = Image.open("Images/Tajmahal_2.jpg")

# Convert the image to grayscale
grayscale_image = ImageOps.grayscale(color_image)

# Display the original and grayscale images
color_image.show()
grayscale_image.show()

Output

Input Image

Output Image

Example 2

Here's an example illustrating the use of the grayscale() function to convert a PNG image with RGBA channels to a grayscale image.

from PIL import Image, ImageOps

# Open an image file
color_image = Image.open("Images/pillow-logo-w.png")

# Convert the image to grayscale
grayscale_image = ImageOps.grayscale(color_image)

# Display the original and grayscale images
color_image.show()
grayscale_image.show()

Output

Input Image

Output Image

Example 3

In this example, we open two images—one in RGB format and the other in RGBA format. Then we apply the ImageOps.grayscale() function to convert them to grayscale. Finally, we print the mode attribute for each image to determine the mode of each image.

The mode attribute will indicate "RGB" or "RGBA" for color images and "L" for grayscale images.

from PIL import Image, ImageOps
import numpy as np

# Open an RGB image file
input_image = Image.open("Images/tutorialspoint2.jpg")

# Open an RGBA image file
image2 = Image.open('Images/pillow-logo-w.png')

# Convert the images to grayscale
grayscale_image = ImageOps.grayscale(input_image)
grayscale_image2 = ImageOps.grayscale(image2)

# Display the color mode of each image
print("Input Image Mode:", input_image.mode)  # Should print 'RGB'
print("Grayscale Image Mode:", grayscale_image.mode)  # Should print 'L' for grayscale

print("Image2 Mode:", image2.mode)  # Should print 'RGB'
print("Grayscale Image2 Mode:", grayscale_image2.mode)  # Should print 'L' for grayscale

Output

Input Image Mode: RGB
Grayscale Image Mode: L
Image2 Mode: RGBA
Grayscale Image2 Mode: L