Python错误集锦：matplotlib imshow()方法显示图像提示：TypeError: Invalid shape (100, 100, 5) for image data

原文链接：http://www.juzicode.com/archives/3502

 

错误提示：

matplotlib的imshow()方法显示图像时提示：TypeError: Invalid shape (100, 100, 5) for image data

#juzicode.com; #vx:桔子code
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

arr = np.full((100,100,3),100)
plt.imshow(arr)

arr = np.full((100,100,5),100)
plt.imshow(arr)

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
 in 
      8 
      9 arr = np.full((100,100,5),100)
---> 10 plt.imshow(arr)

d:\python\python38\lib\site-packages\matplotlib\pyplot.py in imshow(X, cmap, norm, aspect, interpolation, alpha, vmin, vmax, origin, extent, filternorm, filterrad, resample, url, data, **kwargs)
   2722         filternorm=True, filterrad=4.0, resample=None, url=None,
   2723         data=None, **kwargs):
-> 2724     __ret = gca().imshow(
   2725         X, cmap=cmap, norm=norm, aspect=aspect,
   2726         interpolation=interpolation, alpha=alpha, vmin=vmin,

d:\python\python38\lib\site-packages\matplotlib\__init__.py in inner(ax, data, *args, **kwargs)
   1445     def inner(ax, *args, data=None, **kwargs):
   1446         if data is None:
-> 1447             return func(ax, *map(sanitize_sequence, args), **kwargs)
   1448 
   1449         bound = new_sig.bind(ax, *args, **kwargs)

d:\python\python38\lib\site-packages\matplotlib\axes\_axes.py in imshow(self, X, cmap, norm, aspect, interpolation, alpha, vmin, vmax, origin, extent, filternorm, filterrad, resample, url, **kwargs)
   5521                               resample=resample, **kwargs)
   5522 
-> 5523         im.set_data(X)
   5524         im.set_alpha(alpha)
   5525         if im.get_clip_path() is None:

d:\python\python38\lib\site-packages\matplotlib\image.py in set_data(self, A)
    709         if not (self._A.ndim == 2
    710                 or self._A.ndim == 3 and self._A.shape[-1] in [3, 4]):
--> 711             raise TypeError("Invalid shape {} for image data"
    712                             .format(self._A.shape))
    713 

TypeError: Invalid shape (100, 100, 5) for image data

 

错误原因：

1、imshow()方法显示numpy数组，数组要么是2维数组（灰度图），要么是3维数组（彩色图）。如果是3维数组，其第3维必须是3或者4，正好对应了3通道或者4通到彩色图像。错误信息中也有完整提示：

    709         if not (self._A.ndim == 2
    710                 or self._A.ndim == 3 and self._A.shape[-1] in [3, 4]):

 

解决方法：

1、matploglib的imshow()方法如果显示3维数组，只能显示3通道或者4通道的彩色图像，其他通道数没有实际意义。