使用 imageio 保存 3D 绘图

如何解决使用 imageio 保存 3D 绘图

我想将 3D 绘图保存为 gif。但是，由于我无法解释的原因，以下代码不起作用。我收到错误消息：Image must be 2D (grayscale,RGB,or RGBA)，当我使用 imageio.mimsave(...) 时，但我将图像保存为 RGB：

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

x = [0,1,0]
y = [0,0]
z = [0,1]

fig = plt.figure(figsize=(15,9))
ax = fig.add_subplot(projection='3d')
ax.scatter(x,y,z,s=1500)

images = []
for n in range(0,100):
    if n >= 20: 
        ax.azim = ax.azim+1.1 
    fig.canvas.draw()
    image = np.frombuffer(fig.canvas.tostring_rgb(),dtype='uint8')
    images.append(image)
   
imageio.mimsave('test.gif',images)

解决方法

np.frombuffer 返回一个平面数组，其形状为(X*Y*3,)，相反 imageio 需要一个 Y × X × 3 （或者对于 RGBA 缓冲区可能是 × 4）。你必须reshape你的image

In [43]: import numpy as np
    ...: import matplotlib.pyplot as plt
    ...: import imageio
    ...: 
    ...: x = [0,1,0]
    ...: y = [0,0]
    ...: z = [0,1]
    ...: 
    ...: fig = plt.figure(figsize=(5,3)) # @100 dpi it's 500×300 pixels
    ...: ax = fig.add_subplot(projection='3d')
    ...: ax.scatter(x,y,z,s=500)
    ...: 
    ...: images = []
    ...: for n in range(0,25):
    ...:     if n >= 15:
    ...:         ax.azim = ax.azim+1.1
    ...:     fig.canvas.draw()
    ...:     image = np.frombuffer(fig.canvas.tostring_rgb(),dtype='uint8')
    ...:     images.append(image.reshape(300,500,3)) ## Y×X
    ...: 
    ...: imageio.mimsave('test.gif',images)
    ...: 

In [44]: ls -l test.gif
-rw-r--r-- 1 boffi boffi 825988 May 21 19:46 test.gif

In [45]: 

请注意，我已经修改了尺寸和帧数以获得更小的 GIF。