Note
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RGB to grayscale#
This example converts an image with RGB channels into an image with a single grayscale channel.
The value of each grayscale pixel is calculated as the weighted sum of the corresponding red, green and blue pixels as:
Y = 0.2125 R + 0.7154 G + 0.0721 B
These weights are used by CRT phosphors as they better represent human perception of red, green and blue than equal weights. [1]
References#
import matplotlib.pyplot as plt
from skimage import data
from skimage.color import rgb2gray
original = data.astronaut()
grayscale = rgb2gray(original)
fig, axes = plt.subplots(1, 2, figsize=(8, 4))
ax = axes.ravel()
ax[0].imshow(original)
ax[0].set_title("Original")
ax[1].imshow(grayscale, cmap=plt.cm.gray)
ax[1].set_title("Grayscale")
fig.tight_layout()
plt.show()
Total running time of the script: (0 minutes 0.666 seconds)
