Deeppixbis extractor

Added the extractor for DeepPixBiS, since it was not present here, but only in the following paper package: bob.paper.deep_pix_bis_pad.icb2019

I guess it's better to have it here as well !

bob/learn/pytorch/extractor/image/DeepPixBiS.py

@@ -52,24 +52,17 @@ class DeepPixBiSExtractor(Extractor):
       logger.debug("No pretrained file provided")
       pass
     else:
-
-
-      # With the new training
       logger.debug('Starting to load the pretrained PAD model')
-
       try:
         cp = torch.load(model_file)
       except:
-        try:
-          cp= torch.load(model_file,map_location=lambda storage,loc:storage) 
-        except:
-          raise ValueError('Could not load the model')
+        raise ValueError('Failed to load the model file : {}'.format(model_file))
 
       if 'state_dict' in cp:
         self.network.load_state_dict(cp['state_dict'])
-      else: ## check this part
-        self.network.load_state_dict(cp)
-
+      else:
+        raise ValueError('Failed to load the state_dict for model file: {}'.format(model_file))
+      
       logger.debug('Loaded the pretrained PAD model')    
  
     self.network.eval()