text: Title: how to test a custom image or video?
  Body: Hi,
  I am a little confused with the code,it seems just for public dataset. If i want to test a custom image,how to extract the features? I load the se_resnet50, and  print key as follows:
  layer4.2.se_module.fc1.weight
  layer4.2.se_module.fc1.bias
  layer4.2.se_module.fc2.weight
  layer4.2.se_module.fc2.bias
  fc.0.weight
  fc.0.bias
  fc.1.weight
  fc.1.bias
  fc.1.running_mean
  fc.1.running_var
  classifier.weight
  classifier.bias
  
  but, I do not konw i should pick which layer to extract features for distance computation.