Update 8.自动化特征提取器：图像特征提取和深度学习.md

修正 例 8-1 中错误代码格式

docs/8.自动化特征提取器：图像特征提取和深度学习.md

@@ -62,8 +62,8 @@ SIFT最初是为对象识别的任务而开发的，它不仅涉及将图像正
 
 ```python
 import matplotlib.pyplot as plt 
-import numpy as np from skimage 
-import data, color 
+import numpy as np
+from skimage import data, color 
  
 # Load the example image and turn it into grayscale 
 image = color.rgb2gray(data.chelsea()) 
@@ -78,8 +78,10 @@ gx[:, -1] = 0
 gx[:, 1:-1] = image[:, :-2] - image[:, 2:] 
  
 # Same deal for the vertical gradient 
-gy = np.empty(image.shape, dtype=np.double) gy[0, :] = 0 
-gy[-1, :] = 0 gy[1:-1, :] = image[:-2, :] - image[2:, :] 
+gy = np.empty(image.shape, dtype=np.double) 
+gy[0, :] = 0 
+gy[-1, :] = 0 
+gy[1:-1, :] = image[:-2, :] - image[2:, :] 
  
 # Matplotlib incantations 
 fig, (ax1, ax2, ax3) = plt.subplots(3, 1,figsize=(5, 9),sharex=True,sharey=True)