python - 如何从plt.imshow（）或plt.matshow（）提取数据？

要获得在matplotlib轴上绘制的图像的RGBA数组，首先，获取图像对象（在此处im3）。其次，获取其颜色图（此处为ccmap）。最后一步，将数据数组传递im3._A给ccmap。

import matplotlib.cm as cm
import numpy as np
import matplotlib.pyplot as plt 

data = np.random.random((10,10))
# imshow or matshow is OK
#im3 = plt.imshow(data, cmap="viridis_r")  #any colormap will do
im3 = plt.matshow(data, cmap="viridis_r")
plt.axis('off')
#plt.savefig("question2.png",bbox_inches='tight',pad_inches=0)
plt.show()

# get the colormap used by the previous imshow()
ccmap = im3.get_cmap()
print(ccmap.name)  # 'viridis_r'

# get the image data ***YOU ASK FOR THIS***
img_rgba_array = ccmap(im3._A)

# plot the image data
ax = plt.subplot(111)
ax.imshow(img_rgba_array);  #dont need any cmap to plot

样例输出图：