File size: 24,121 Bytes
36d9761
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
import argparse
import json
from PIL import Image
from torchvision import transforms
import torch.nn.functional as F
from glob import glob

import cv2
import math
import numpy as np
import os
import os.path as osp
import random
import time
import torch
from pathlib import Path
from torch.utils import data as data

from basicsr.utils import DiffJPEG, USMSharp
from basicsr.utils.img_process_util import filter2D
from basicsr.data.transforms import paired_random_crop, triplet_random_crop
from basicsr.data.degradations import random_add_gaussian_noise_pt, random_add_poisson_noise_pt, random_add_speckle_noise_pt, random_add_saltpepper_noise_pt, bivariate_Gaussian

from basicsr.data.degradations import circular_lowpass_kernel, random_mixed_kernels
from basicsr.data.transforms import augment
from basicsr.utils import FileClient, get_root_logger, imfrombytes, img2tensor
from basicsr.utils.registry import DATASET_REGISTRY

def parse_args_paired_training(input_args=None):
    """
    Parses command-line arguments used for configuring an paired session (pix2pix-Turbo).
    This function sets up an argument parser to handle various training options.

    Returns:
    argparse.Namespace: The parsed command-line arguments.
   """
    parser = argparse.ArgumentParser()
    # args for the loss function
    parser.add_argument("--gan_disc_type", default="vagan")
    parser.add_argument("--gan_loss_type", default="multilevel_sigmoid_s")
    parser.add_argument("--lambda_gan", default=0.5, type=float)
    parser.add_argument("--lambda_lpips", default=5.0, type=float)
    parser.add_argument("--lambda_l2", default=2.0, type=float)
    parser.add_argument("--base_config", default="./configs/sr.yaml", type=str)

    # validation eval args
    parser.add_argument("--eval_freq", default=100, type=int)
    parser.add_argument("--save_val", default=True, action="store_false")
    parser.add_argument("--num_samples_eval", type=int, default=100, help="Number of samples to use for all evaluation")

    parser.add_argument("--viz_freq", type=int, default=100, help="Frequency of visualizing the outputs.")

    # details about the model architecture
    parser.add_argument("--sd_path")
    parser.add_argument("--pretrained_path", type=str, default=None,)
    parser.add_argument("--de_net_path")
    parser.add_argument("--revision", type=str, default=None,)
    parser.add_argument("--variant", type=str, default=None,)
    parser.add_argument("--tokenizer_name", type=str, default=None)
    parser.add_argument("--lora_rank_unet", default=32, type=int)
    parser.add_argument("--lora_rank_vae", default=16, type=int)
    parser.add_argument("--neg_prob", default=0.05, type=float)
    parser.add_argument("--pos_prompt", type=str, default="A high-resolution, 8K, ultra-realistic image with sharp focus, vibrant colors, and natural lighting.")
    parser.add_argument("--neg_prompt", type=str, default="oil painting, cartoon, blur, dirty, messy, low quality, deformation, low resolution, oversmooth")

    # training details
    parser.add_argument("--output_dir", required=True)
    parser.add_argument("--cache_dir", default=None,)
    parser.add_argument("--seed", type=int, default=None, help="A seed for reproducible training.")
    parser.add_argument("--resolution", type=int, default=512,)
    parser.add_argument("--train_batch_size", type=int, default=4, help="Batch size (per device) for the training dataloader.")
    parser.add_argument("--num_training_epochs", type=int, default=50)
    parser.add_argument("--max_train_steps", type=int, default=50000,)
    parser.add_argument("--checkpointing_steps", type=int, default=500,)
    parser.add_argument("--gradient_accumulation_steps", type=int, default=4, help="Number of updates steps to accumulate before performing a backward/update pass.",)
    parser.add_argument("--gradient_checkpointing", action="store_true",)
    parser.add_argument("--learning_rate", type=float, default=2e-5)
    parser.add_argument("--lr_scheduler", type=str, default="constant",
        help=(
            'The scheduler type to use. Choose between ["linear", "cosine", "cosine_with_restarts", "polynomial",'
            ' "constant", "piecewise_constant", "constant_with_warmup"]'
        ),
    )
    parser.add_argument("--lr_warmup_steps", type=int, default=500, help="Number of steps for the warmup in the lr scheduler.")
    parser.add_argument("--lr_num_cycles", type=int, default=1,
        help="Number of hard resets of the lr in cosine_with_restarts scheduler.",
    )
    parser.add_argument("--lr_power", type=float, default=0.1, help="Power factor of the polynomial scheduler.")

    parser.add_argument("--dataloader_num_workers", type=int, default=0,)
    parser.add_argument("--adam_beta1", type=float, default=0.9, help="The beta1 parameter for the Adam optimizer.")
    parser.add_argument("--adam_beta2", type=float, default=0.999, help="The beta2 parameter for the Adam optimizer.")
    parser.add_argument("--adam_weight_decay", type=float, default=1e-2, help="Weight decay to use.")
    parser.add_argument("--adam_epsilon", type=float, default=1e-08, help="Epsilon value for the Adam optimizer")
    parser.add_argument("--max_grad_norm", default=1.0, type=float, help="Max gradient norm.")
    parser.add_argument("--allow_tf32", action="store_true",
        help=(
            "Whether or not to allow TF32 on Ampere GPUs. Can be used to speed up training. For more information, see"
            " https://pytorch.org/docs/stable/notes/cuda.html#tensorfloat-32-tf32-on-ampere-devices"
        ),
    )
    parser.add_argument("--report_to", type=str, default="wandb",
        help=(
            'The integration to report the results and logs to. Supported platforms are `"tensorboard"`'
            ' (default), `"wandb"` and `"comet_ml"`. Use `"all"` to report to all integrations.'
        ),
    )
    parser.add_argument("--mixed_precision", type=str, default=None, choices=["no", "fp16", "bf16"],)
    parser.add_argument("--enable_xformers_memory_efficient_attention", action="store_true", help="Whether or not to use xformers.")
    parser.add_argument("--set_grads_to_none", action="store_true",)

    if input_args is not None:
        args = parser.parse_args(input_args)
    else:
        args = parser.parse_args()

    return args


# @DATASET_REGISTRY.register(suffix='basicsr')
class PairedDataset(data.Dataset):
    """Modified dataset based on the dataset used for Real-ESRGAN model:
    Real-ESRGAN: Training Real-World Blind Super-Resolution with Pure Synthetic Data.

    It loads gt (Ground-Truth) images, and augments them.
    It also generates blur kernels and sinc kernels for generating low-quality images.
    Note that the low-quality images are processed in tensors on GPUS for faster processing.

    Args:
        opt (dict): Config for train datasets. It contains the following keys:
            dataroot_gt (str): Data root path for gt.
            meta_info (str): Path for meta information file.
            io_backend (dict): IO backend type and other kwarg.
            use_hflip (bool): Use horizontal flips.
            use_rot (bool): Use rotation (use vertical flip and transposing h and w for implementation).
            Please see more options in the codes.
    """

    def __init__(self, opt):
        super(PairedDataset, self).__init__()
        self.opt = opt
        self.file_client = None
        self.io_backend_opt = opt['io_backend']
        if 'crop_size' in opt:
            self.crop_size = opt['crop_size']
        else:
            self.crop_size = 512
        if 'image_type' not in opt:
            opt['image_type'] = 'png'

        # support multiple type of data: file path and meta data, remove support of lmdb
        self.paths = []
        if 'meta_info' in opt:
            with open(self.opt['meta_info']) as fin:
                    paths = [line.strip().split(' ')[0] for line in fin]
                    self.paths = [v for v in paths]
            if 'meta_num' in opt:
                self.paths = sorted(self.paths)[:opt['meta_num']]
        if 'gt_path' in opt:
            if isinstance(opt['gt_path'], str):
                # Use rglob to recursively search for images
                self.paths.extend(sorted([str(x) for x in Path(opt['gt_path']).rglob('*.' + opt['image_type'])]))
            else:
                for path in opt['gt_path']:
                    self.paths.extend(sorted([str(x) for x in Path(path).rglob('*.' + opt['image_type'])]))
                
        # if 'gt_path' in opt:
        #     if isinstance(opt['gt_path'], str):
        #         self.paths.extend(sorted([str(x) for x in Path(opt['gt_path']).glob('*.'+opt['image_type'])]))
        #     else:
        #         self.paths.extend(sorted([str(x) for x in Path(opt['gt_path'][0]).glob('*.'+opt['image_type'])]))
        #         if len(opt['gt_path']) > 1:
        #             for i in range(len(opt['gt_path'])-1):
        #                 self.paths.extend(sorted([str(x) for x in Path(opt['gt_path'][i+1]).glob('*.'+opt['image_type'])]))
        if 'imagenet_path' in opt:
            class_list = os.listdir(opt['imagenet_path'])
            for class_file in class_list:
                self.paths.extend(sorted([str(x) for x in Path(os.path.join(opt['imagenet_path'], class_file)).glob('*.'+'JPEG')]))
        if 'face_gt_path' in opt:
            if isinstance(opt['face_gt_path'], str):
                face_list = sorted([str(x) for x in Path(opt['face_gt_path']).glob('*.'+opt['image_type'])])
                self.paths.extend(face_list[:opt['num_face']])
            else:
                face_list = sorted([str(x) for x in Path(opt['face_gt_path'][0]).glob('*.'+opt['image_type'])])
                self.paths.extend(face_list[:opt['num_face']])
                if len(opt['face_gt_path']) > 1:
                    for i in range(len(opt['face_gt_path'])-1):
                        self.paths.extend(sorted([str(x) for x in Path(opt['face_gt_path'][0]).glob('*.'+opt['image_type'])])[:opt['num_face']])

        # limit number of pictures for test
        if 'num_pic' in opt:
            if 'val' or 'test' in opt:
                random.shuffle(self.paths)
                self.paths = self.paths[:opt['num_pic']]
            else:
                self.paths = self.paths[:opt['num_pic']]

        if 'mul_num' in opt:
            self.paths = self.paths * opt['mul_num']
            # print('>>>>>>>>>>>>>>>>>>>>>')
            # print(self.paths)

        # blur settings for the first degradation
        self.blur_kernel_size = opt['blur_kernel_size']
        self.kernel_list = opt['kernel_list']
        self.kernel_prob = opt['kernel_prob']  # a list for each kernel probability
        self.blur_sigma = opt['blur_sigma']
        self.betag_range = opt['betag_range']  # betag used in generalized Gaussian blur kernels
        self.betap_range = opt['betap_range']  # betap used in plateau blur kernels
        self.sinc_prob = opt['sinc_prob']  # the probability for sinc filters

        # blur settings for the second degradation
        self.blur_kernel_size2 = opt['blur_kernel_size2']
        self.kernel_list2 = opt['kernel_list2']
        self.kernel_prob2 = opt['kernel_prob2']
        self.blur_sigma2 = opt['blur_sigma2']
        self.betag_range2 = opt['betag_range2']
        self.betap_range2 = opt['betap_range2']
        self.sinc_prob2 = opt['sinc_prob2']

        # a final sinc filter
        self.final_sinc_prob = opt['final_sinc_prob']

        self.kernel_range = [2 * v + 1 for v in range(3, 11)]  # kernel size ranges from 7 to 21
        # TODO: kernel range is now hard-coded, should be in the configure file
        self.pulse_tensor = torch.zeros(21, 21).float()  # convolving with pulse tensor brings no blurry effect
        self.pulse_tensor[10, 10] = 1

    def __getitem__(self, index):
        if self.file_client is None:
            self.file_client = FileClient(self.io_backend_opt.pop('type'), **self.io_backend_opt)

        # -------------------------------- Load gt images -------------------------------- #
        # Shape: (h, w, c); channel order: BGR; image range: [0, 1], float32.
        gt_path = self.paths[index]
        # avoid errors caused by high latency in reading files
        retry = 3
        while retry > 0:
            try:
                img_bytes = self.file_client.get(gt_path, 'gt')
            except (IOError, OSError) as e:
                # logger = get_root_logger()
                # logger.warn(f'File client error: {e}, remaining retry times: {retry - 1}')
                # change another file to read
                index = random.randint(0, self.__len__()-1)
                gt_path = self.paths[index]
                time.sleep(1)  # sleep 1s for occasional server congestion
            else:
                break
            finally:
                retry -= 1
        img_gt = imfrombytes(img_bytes, float32=True)
        # filter the dataset and remove images with too low quality
        img_size = os.path.getsize(gt_path)
        img_size = img_size / 1024

        while img_gt.shape[0] * img_gt.shape[1] < 384*384 or img_size<100:
            index = random.randint(0, self.__len__()-1)
            gt_path = self.paths[index]

            time.sleep(0.1)  # sleep 1s for occasional server congestion
            img_bytes = self.file_client.get(gt_path, 'gt')
            img_gt = imfrombytes(img_bytes, float32=True)
            img_size = os.path.getsize(gt_path)
            img_size = img_size / 1024

        # -------------------- Do augmentation for training: flip, rotation -------------------- #
        img_gt = augment(img_gt, self.opt['use_hflip'], self.opt['use_rot'])

        # crop or pad to 400
        # TODO: 400 is hard-coded. You may change it accordingly
        h, w = img_gt.shape[0:2]
        crop_pad_size = self.crop_size
        # pad
        if h < crop_pad_size or w < crop_pad_size:
            pad_h = max(0, crop_pad_size - h)
            pad_w = max(0, crop_pad_size - w)
            img_gt = cv2.copyMakeBorder(img_gt, 0, pad_h, 0, pad_w, cv2.BORDER_REFLECT_101)
        # crop
        if img_gt.shape[0] > crop_pad_size or img_gt.shape[1] > crop_pad_size:
            h, w = img_gt.shape[0:2]
            # randomly choose top and left coordinates
            top = random.randint(0, h - crop_pad_size)
            left = random.randint(0, w - crop_pad_size)
            # top = (h - crop_pad_size) // 2 -1
            # left = (w - crop_pad_size) // 2 -1
            img_gt = img_gt[top:top + crop_pad_size, left:left + crop_pad_size, ...]

        # ------------------------ Generate kernels (used in the first degradation) ------------------------ #
        kernel_size = random.choice(self.kernel_range)
        if np.random.uniform() < self.opt['sinc_prob']:
            # this sinc filter setting is for kernels ranging from [7, 21]
            if kernel_size < 13:
                omega_c = np.random.uniform(np.pi / 3, np.pi)
            else:
                omega_c = np.random.uniform(np.pi / 5, np.pi)
            kernel = circular_lowpass_kernel(omega_c, kernel_size, pad_to=False)
        else:
            kernel = random_mixed_kernels(
                self.kernel_list,
                self.kernel_prob,
                kernel_size,
                self.blur_sigma,
                self.blur_sigma, [-math.pi, math.pi],
                self.betag_range,
                self.betap_range,
                noise_range=None)
        # pad kernel
        pad_size = (21 - kernel_size) // 2
        kernel = np.pad(kernel, ((pad_size, pad_size), (pad_size, pad_size)))

        # ------------------------ Generate kernels (used in the second degradation) ------------------------ #
        kernel_size = random.choice(self.kernel_range)
        if np.random.uniform() < self.opt['sinc_prob2']:
            if kernel_size < 13:
                omega_c = np.random.uniform(np.pi / 3, np.pi)
            else:
                omega_c = np.random.uniform(np.pi / 5, np.pi)
            kernel2 = circular_lowpass_kernel(omega_c, kernel_size, pad_to=False)
        else:
            kernel2 = random_mixed_kernels(
                self.kernel_list2,
                self.kernel_prob2,
                kernel_size,
                self.blur_sigma2,
                self.blur_sigma2, [-math.pi, math.pi],
                self.betag_range2,
                self.betap_range2,
                noise_range=None)

        # pad kernel
        pad_size = (21 - kernel_size) // 2
        kernel2 = np.pad(kernel2, ((pad_size, pad_size), (pad_size, pad_size)))

        # ------------------------------------- the final sinc kernel ------------------------------------- #
        if np.random.uniform() < self.opt['final_sinc_prob']:
            kernel_size = random.choice(self.kernel_range)
            omega_c = np.random.uniform(np.pi / 3, np.pi)
            sinc_kernel = circular_lowpass_kernel(omega_c, kernel_size, pad_to=21)
            sinc_kernel = torch.FloatTensor(sinc_kernel)
        else:
            sinc_kernel = self.pulse_tensor

        # BGR to RGB, HWC to CHW, numpy to tensor
        img_gt = img2tensor([img_gt], bgr2rgb=True, float32=True)[0]
        kernel = torch.FloatTensor(kernel)
        kernel2 = torch.FloatTensor(kernel2)

        return_d = {'gt': img_gt, 'kernel1': kernel, 'kernel2': kernel2, 'sinc_kernel': sinc_kernel, 'gt_path': gt_path}
        return return_d

    def __len__(self):
        return len(self.paths)


def randn_cropinput(lq, gt, base_size=[64, 128, 256, 512]):
    cur_size_h = random.choice(base_size)
    cur_size_w = random.choice(base_size)
    init_h = lq.size(-2)//2
    init_w = lq.size(-1)//2
    lq = lq[:, :, init_h-cur_size_h//2:init_h+cur_size_h//2, init_w-cur_size_w//2:init_w+cur_size_w//2]
    gt = gt[:, :, init_h-cur_size_h//2:init_h+cur_size_h//2, init_w-cur_size_w//2:init_w+cur_size_w//2]
    assert lq.size(-1)>=64
    assert lq.size(-2)>=64
    return [lq, gt]


def degradation_proc(configs, batch, device, val=False, use_usm=False, resize_lq=True, random_size=False):

    """Degradation pipeline, modified from Real-ESRGAN:
    https://github.com/xinntao/Real-ESRGAN
    """

    jpeger = DiffJPEG(differentiable=False).cuda()  # simulate JPEG compression artifacts
    usm_sharpener = USMSharp().cuda()  # do usm sharpening

    im_gt = batch['gt'].cuda()
    if use_usm:
        im_gt = usm_sharpener(im_gt)
    im_gt = im_gt.to(memory_format=torch.contiguous_format).float()
    kernel1 = batch['kernel1'].cuda()
    kernel2 = batch['kernel2'].cuda()
    sinc_kernel = batch['sinc_kernel'].cuda()

    ori_h, ori_w = im_gt.size()[2:4]

    # ----------------------- The first degradation process ----------------------- #
    # blur
    out = filter2D(im_gt, kernel1)
    # random resize
    updown_type = random.choices(
            ['up', 'down', 'keep'],
            configs.degradation['resize_prob'],
            )[0]
    if updown_type == 'up':
        scale = random.uniform(1, configs.degradation['resize_range'][1])
    elif updown_type == 'down':
        scale = random.uniform(configs.degradation['resize_range'][0], 1)
    else:
        scale = 1
    mode = random.choice(['area', 'bilinear', 'bicubic'])
    out = F.interpolate(out, scale_factor=scale, mode=mode)
    # add noise
    gray_noise_prob = configs.degradation['gray_noise_prob']
    if random.random() < configs.degradation['gaussian_noise_prob']:
        out = random_add_gaussian_noise_pt(
            out,
            sigma_range=configs.degradation['noise_range'],
            clip=True,
            rounds=False,
            gray_prob=gray_noise_prob,
            )
    else:
        out = random_add_poisson_noise_pt(
            out,
            scale_range=configs.degradation['poisson_scale_range'],
            gray_prob=gray_noise_prob,
            clip=True,
            rounds=False)
    # JPEG compression
    jpeg_p = out.new_zeros(out.size(0)).uniform_(*configs.degradation['jpeg_range'])
    out = torch.clamp(out, 0, 1)  # clamp to [0, 1], otherwise JPEGer will result in unpleasant artifacts
    out = jpeger(out, quality=jpeg_p)

    # ----------------------- The second degradation process ----------------------- #
    # blur
    if random.random() < configs.degradation['second_blur_prob']:
        out = filter2D(out, kernel2)
    # random resize
    updown_type = random.choices(
            ['up', 'down', 'keep'],
            configs.degradation['resize_prob2'],
            )[0]
    if updown_type == 'up':
        scale = random.uniform(1, configs.degradation['resize_range2'][1])
    elif updown_type == 'down':
        scale = random.uniform(configs.degradation['resize_range2'][0], 1)
    else:
        scale = 1
    mode = random.choice(['area', 'bilinear', 'bicubic'])
    out = F.interpolate(
            out,
            size=(int(ori_h / configs.sf * scale),
                  int(ori_w / configs.sf * scale)),
            mode=mode,
            )
    # add noise
    gray_noise_prob = configs.degradation['gray_noise_prob2']
    if random.random() < configs.degradation['gaussian_noise_prob2']:
        out = random_add_gaussian_noise_pt(
            out,
            sigma_range=configs.degradation['noise_range2'],
            clip=True,
            rounds=False,
            gray_prob=gray_noise_prob,
            )
    else:
        out = random_add_poisson_noise_pt(
            out,
            scale_range=configs.degradation['poisson_scale_range2'],
            gray_prob=gray_noise_prob,
            clip=True,
            rounds=False,
            )

    # JPEG compression + the final sinc filter
    # We also need to resize images to desired sizes. We group [resize back + sinc filter] together
    # as one operation.
    # We consider two orders:
    #   1. [resize back + sinc filter] + JPEG compression
    #   2. JPEG compression + [resize back + sinc filter]
    # Empirically, we find other combinations (sinc + JPEG + Resize) will introduce twisted lines.
    if random.random() < 0.5:
        # resize back + the final sinc filter
        mode = random.choice(['area', 'bilinear', 'bicubic'])
        out = F.interpolate(
                out,
                size=(ori_h // configs.sf,
                      ori_w // configs.sf),
                mode=mode,
                )
        out = filter2D(out, sinc_kernel)
        # JPEG compression
        jpeg_p = out.new_zeros(out.size(0)).uniform_(*configs.degradation['jpeg_range2'])
        out = torch.clamp(out, 0, 1)
        out = jpeger(out, quality=jpeg_p)
    else:
        # JPEG compression
        jpeg_p = out.new_zeros(out.size(0)).uniform_(*configs.degradation['jpeg_range2'])
        out = torch.clamp(out, 0, 1)
        out = jpeger(out, quality=jpeg_p)
        # resize back + the final sinc filter
        mode = random.choice(['area', 'bilinear', 'bicubic'])
        out = F.interpolate(
                out,
                size=(ori_h // configs.sf,
                      ori_w // configs.sf),
                mode=mode,
                )
        out = filter2D(out, sinc_kernel)

    # clamp and round
    im_lq = torch.clamp(out, 0, 1.0)

    # random crop
    gt_size = configs.degradation['gt_size']
    im_gt, im_lq = paired_random_crop(im_gt, im_lq, gt_size, configs.sf)
    lq, gt = im_lq, im_gt
    ori_lq = im_lq

    if resize_lq:
        lq = F.interpolate(
                lq,
                size=(gt.size(-2),
                      gt.size(-1)),
                mode='bicubic',
                )

    if random.random() < configs.degradation['no_degradation_prob'] or torch.isnan(lq).any():
        lq = gt

    # sharpen self.gt again, as we have changed the self.gt with self._dequeue_and_enqueue
    lq = lq.contiguous()  # for the warning: grad and param do not obey the gradient layout contract
    lq = lq * 2 - 1.0 # TODO 0~1?
    gt = gt * 2 - 1.0

    if random_size:
        lq, gt = randn_cropinput(lq, gt)

    lq = torch.clamp(lq, -1.0, 1.0)

    return lq.to(device), gt.to(device), ori_lq.to(device)