How can I convert an RGB image into grayscale in Python?

Question

I\'m trying to use matplotlib to read in an RGB image and convert it to grayscale.

In matlab I use this:

img = rgb2gray(imread(\'image.p         


        

Answer 1

You can also use scikit-image, which provides some functions to convert an image in ndarray, like rgb2gray.

from skimage import color
from skimage import io

img = color.rgb2gray(io.imread('image.png'))

Notes: The weights used in this conversion are calibrated for contemporary CRT phosphors: Y = 0.2125 R + 0.7154 G + 0.0721 B

Alternatively, you can read image in grayscale by:

from skimage import io
img = io.imread('image.png', as_gray=True)