diff --git a/codes/data/torch_dataset.py b/codes/data/torch_dataset.py
index ca259e8f..0917483c 100644
--- a/codes/data/torch_dataset.py
+++ b/codes/data/torch_dataset.py
@@ -35,15 +35,16 @@ class TorchDataset(Dataset):
             ]
         transforms = T.Compose(transforms)
         self.dataset = DATASET_MAP[opt['dataset']](transform=transforms, **opt['kwargs'])
-        self.len = opt['fixed_len'] if 'fixed_len' in opt.keys() else len(self.dataset)
+        self.len = opt_get(opt, ['fixed_len'], len(self.dataset))
+        self.offset = opt_get(opt, ['offset'], 0)
 
     def __getitem__(self, item):
-        underlying_item, lbl = self.dataset[item]
+        underlying_item, lbl = self.dataset[item+self.offset]
         return {'lq': underlying_item, 'hq': underlying_item, 'labels': lbl,
                 'LQ_path': str(item), 'GT_path': str(item)}
 
     def __len__(self):
-        return self.len
+        return self.len-self.offset
 
 if __name__ == '__main__':
     opt = {