Python：如何将“便士”图像颜色（铜色）更改为不同的灰度级？

Question

Python：如何将“便士”图像颜色（铜色）更改为不同的灰度级？图中给出的例子

import numpy as np 
import scipy.io as sio 
import matplotlib.pyplot as plt 
import matplotlib.image as mpimg 

plt.clf()

p = plt.imread ('penny.jpg') 
plt.imshow(p) 

penny = p.copy() 

Answer 1

转换为灰度代码来自https://stackoverflow.com/a/12201744/1092820

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.image as mpimg

# Import the image
p = plt.imread('penny.png')

# Convert to grayscale
gray = np.dot(p[...,:3],[0.299, 0.587, 0.114])

# Round gray to nearest 1/n, where n is how many grays:
grayCount = 4
roundedGray = np.floor(gray * float(grayCount)) / float(grayCount)

# Display using matplotlib's copper color mapping
plt.imshow(roundedGray, cmap=plt.get_cmap('copper'))

plt.show()