text: Title: Issues about why it always skips the images that I upload
  Body: Hi, recently I tried your Colab demo to restore some of my old images, but here comes the issue. When I follow the steps and run the code, it always prints skip the my uploaded images like the following shows:
  
  Running Stage 1: Overall restoration
  initializing the dataloader
  model weights loaded
  directory of testing image: /content/photo_restoration/test_images/upload
  processing testScratch.png
  You are using NL + Res
  Now you are processing testScratch.png
  Skip testScratch.png
  Finish Stage 1 ...
  
  
  Running Stage 2: Face Detection
  Finish Stage 2 ...
  
  
  Running Stage 3: Face Enhancement
  The main GPU is 
  0
  dataset [FaceTestDataset] of size 0 was created
  The size of the latent vector size is [8,8]
  Network [SPADEGenerator] was created. Total number of parameters: 92.1 million. To see the architecture, do print(network).
  hi :)
  Finish Stage 3 ...
  
  
  Running Stage 4: Blending
  Finish Stage 4 ...
  
  
  All the processing is done. Please check the results.
  
  Therefore, I'd like to know whether there are any requirements that the uploaded images have to satisfy or did I make some mistakes ? Thanks a lot.