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.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 @DATASET_REGISTRY.register(suffix='basicsr') class RealESRGANDataset(data.Dataset): """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(RealESRGANDataset, self).__init__() self.opt = opt self.file_client = None self.io_backend_opt = opt['io_backend'] # file client (lmdb io backend) self.paths = sorted([str(x) for x in Path(opt['df2k_path']).glob('*.png')]) self.paths.extend(sorted([str(x) for x in Path(opt['wed_path']).glob('*.bmp')])) # 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__()) 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) # -------------------- 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 = 400 # 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) 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)