不能在sklearn中使用LFW數據集

Question

似乎fetch_lfw_people函數不起作用，但我不明白爲什麼。

這裏是測試代碼：

In [1]: import numpy as np 

In [2]: from sklearn import datasets 

In [3]: lfw= datasets.fetch_lfw_people() 

IOError         Traceback (most recent call last) 
<ipython-input-3-1f0795d3f6a9> in <module>() 
----> 1 lfw= datasets.fetch_lfw_people() 

C:\Python27\lib\site-packages\sklearn\datasets\lfw.pyc in fetch_lfw_people(data_ 
home, funneled, resize, min_faces_per_person, color, slice_, download_if_missing 
) 
    270  faces, target, target_names = load_func(
    271   data_folder_path, resize=resize, 
--> 272   min_faces_per_person=min_faces_per_person, color=color, slice_=s 
lice_) 
    273 
    274  # pack the results as a Bunch instance 

C:\Python27\lib\site-packages\sklearn\externals\joblib\memory.pyc in __call__(se 
lf, *args, **kwargs) 
    169       'directory %s' 
    170       % (name, argument_hash, output_dir)) 
--> 171    return self.call(*args, **kwargs) 
    172   else: 
    173    try: 

C:\Python27\lib\site-packages\sklearn\externals\joblib\memory.pyc in call(self, 
*args, **kwargs) 
    321   if self._verbose: 
    322    print self.format_call(*args, **kwargs) 
--> 323   output = self.func(*args, **kwargs) 
    324   self._persist_output(output, output_dir) 
    325   duration = time.time() - start_time 

C:\Python27\lib\site-packages\sklearn\datasets\lfw.pyc in _fetch_lfw_people(data 
_folder_path, slice_, color, resize, min_faces_per_person) 
    195  target = np.searchsorted(target_names, person_names) 
    196 
--> 197  faces = _load_imgs(file_paths, slice_, color, resize) 
    198 
    199  # shuffle the faces with a deterministic RNG scheme to avoid having 

C:\Python27\lib\site-packages\sklearn\datasets\lfw.pyc in _load_imgs(file_paths, 
slice_, color, resize) 
    149   if i % 1000 == 0: 
    150    logger.info("Loading face #%05d/%05d", i + 1, n_faces) 
--> 151   face = np.asarray(imread(file_path)[slice_], dtype=np.float32) 
    152   face /= 255.0 # scale uint8 coded colors to the [0.0, 1.0] floa 
ts 
    153   if resize is not None: 

C:\Python27\lib\site-packages\scipy\misc\pilutil.pyc in imread(name, flatten) 
    100  """ 
    101 
--> 102  im = Image.open(name) 
    103  return fromimage(im,flatten=flatten) 
    104 

C:\Python27\lib\site-packages\PIL\Image.pyc in open(fp, mode) 
    1978     pass 
    1979 
-> 1980  raise IOError("cannot identify image file") 
    1981 
    1982 # 

IOError: cannot identify image file 

Answer 1

嘗試使用這讓你的圖片

dataset = fetch_lfw_pairs(subset='train', 
          data_home=None, 
          resize=0.5, 
          color=False, 
          slice_=(slice(70, 195), slice(78, 172)), 
          download_if_missing=True)