text: import torch.utils.data as data
  
  from dataset_helper import common
  
  
  class LRDataset(data.Dataset):
      '''
      Read LR images only in test phase.
      '''
  
      def name(self):
          return common.find_benchmark(self.opt['dataroot_LR'])
  
  
      def __init__(self, opt):
          super(LRDataset, self).__init__()
          self.opt = opt
          self.scale = self.opt['scale']
          self.paths_LR = None
  
          # read image list from image/binary files
          self.paths_LR = common.get_image_paths(opt['data_type'], opt['dataroot_LR'])
          assert self.paths_LR, '[Error] LR paths are empty.'
  
  
      def __getitem__(self, idx):
          # get LR image
          lr, lr_path = self._load_file(idx)
          lr_tensor = common.np2Tensor([lr], self.opt['rgb_range'])[0]
          return {'LR': lr_tensor, 'LR_path': lr_path}
  
  
      def __len__(self):
          return len(self.paths_LR)
  
  
      def _load_file(self, idx):
          lr_path = self.paths_LR[idx]
          lr = common.read_img(lr_path, self.opt['data_type'])
  
          return lr, lr_path