DL-Art-School/codes/data/LQ_dataset.py

63 lines
2.1 KiB
Python

import numpy as np
import lmdb
import torch
import torch.utils.data as data
import data.util as util
import torchvision.transforms.functional as F
from PIL import Image
import os.path as osp
class LQDataset(data.Dataset):
'''Read LQ images only in the test phase.'''
def __init__(self, opt):
super(LQDataset, self).__init__()
self.opt = opt
self.data_type = self.opt['data_type']
if 'start_at' in self.opt.keys():
self.start_at = self.opt['start_at']
else:
self.start_at = 0
self.vertical_splits = self.opt['vertical_splits']
self.paths_LQ, self.paths_GT = None, None
self.LQ_env = None # environment for lmdb
self.paths_LQ, self.sizes_LQ = util.get_image_paths(self.data_type, opt['dataroot_LQ'])
self.paths_LQ = self.paths_LQ[self.start_at:]
assert self.paths_LQ, 'Error: LQ paths are empty.'
def _init_lmdb(self):
self.LQ_env = lmdb.open(self.opt['dataroot_LQ'], readonly=True, lock=False, readahead=False,
meminit=False)
def __getitem__(self, index):
if self.data_type == 'lmdb' and self.LQ_env is None:
self._init_lmdb()
if self.vertical_splits > 0:
actual_index = int(index / self.vertical_splits)
else:
actual_index = index
# get LQ image
LQ_path = self.paths_LQ[actual_index]
img_LQ = Image.open(LQ_path)
if self.vertical_splits > 0:
w, h = img_LQ.size
split_index = (index % self.vertical_splits)
w_per_split = int(w / self.vertical_splits)
left = w_per_split * split_index
img_LQ = F.crop(img_LQ, 0, left, h, w_per_split)
img_LQ = F.to_tensor(img_LQ)
img_name = osp.splitext(osp.basename(LQ_path))[0]
LQ_path = LQ_path.replace(img_name, img_name + "_%i" % (index % self.vertical_splits))
return {'LQ': img_LQ, 'LQ_path': LQ_path}
def __len__(self):
if self.vertical_splits > 0:
return len(self.paths_LQ) * self.vertical_splits
else:
return len(self.paths_LQ)