import os
import math
from decimal import Decimal
import utility
import torch
from torch.autograd import Variable
from tqdm import tqdm
class Trainer(object):
def __init__(self, args, loader, my_model, my_loss, ckp):
self.args = args
self.scale = args.scale
self.ckp = ckp
self.loader_train = loader.loader_train
self.loader_test = loader.loader_test
self.model = my_model
self.loss = my_loss
self.optimizer = utility.make_optimizer(args, self.model)
self.scheduler = utility.make_scheduler(args, self.optimizer)
if self.args.load != '.':
self.optimizer.load_state_dict(
torch.load(os.path.join(ckp.dir, 'optimizer.pt'))
)
for _ in range(len(ckp.log)): self.scheduler.step()
self.error_last = 1e8
def train(self):
self.scheduler.step()
self.loss.step()
epoch = self.scheduler.last_epoch + 1
lr = self.scheduler.get_lr()[0]
self.ckp.write_log(
'[Epoch {}]\tLearning rate: {:.2e}'.format(epoch, Decimal(lr))
)
self.loss.start_log()
self.model.train()
# from IPython import embed; embed(); exit()
timer_data, timer_model = utility.timer(), utility.timer()
for batch, (lr, hr, _, idx_scale) in enumerate(self.loader_train):
lr, hr = self.prepare([lr, hr])
timer_data.hold()
timer_model.tic()
# from IPython import embed; embed(); exit()
self.optimizer.zero_grad()
sr = self.model(idx_scale, lr)
loss = self.loss(sr, hr)
if loss.item() < self.args.skip_threshold * self.error_last:
loss.backward()
self.optimizer.step()
else:
print('Skip this batch {}! (Loss: {})'.format(
batch + 1, loss.item()
))
timer_model.hold()
if (batch + 1) % self.args.print_every == 0:
self.ckp.write_log('[{}/{}]\t{}\t{:.3f}+{:.3f}s'.format(
(batch + 1) * self.args.batch_size,
len(self.loader_train.dataset),
self.loss.display_loss(batch),
timer_model.release(),
timer_data.release()))
timer_data.tic()
self.loss.end_log(len(self.loader_train))
self.error_last = self.loss.log[-1, -1]
def test(self):
epoch = self.scheduler.last_epoch + 1
self.ckp.write_log('\nEvaluation:')
self.ckp.add_log(torch.zeros(1, len(self.scale)))
self.model.eval()
timer_test = utility.timer()
with torch.no_grad():
for idx_scale, scale in enumerate(self.scale):
eval_acc = 0
self.loader_test.dataset.set_scale(idx_scale)
tqdm_test = tqdm(self.loader_test, ncols=80)
for idx_img, (lr, hr, filename, _) in enumerate(tqdm_test):
# from IPython import embed; embed();
filename = filename[0]
no_eval = (hr.nelement() == 1)
if not no_eval:
lr, hr = self.prepare([lr, hr])
else:
lr = self.prepare([lr])[0]
sr = self.model(idx_scale, lr)
sr = utility.quantize(sr, self.args.rgb_range)
save_list = [sr]
if not no_eval:
eval_acc += utility.calc_psnr(
sr, hr, scale, self.args.rgb_range,
benchmark=self.loader_test.dataset.benchmark
)
save_list.extend([lr, hr])
if self.args.save_results:
self.ckp.save_results(filename, save_list, scale)
self.ckp.log[-1, idx_scale] = eval_acc / len(self.loader_test)
best = self.ckp.log.max(0)
self.ckp.write_log(
'[{} x{}]\tPSNR: {:.3f} (Best: {:.3f} @epoch {})'.format(
self.args.data_test,
scale,
self.ckp.log[-1, idx_scale],
best[0][idx_scale],
best[1][idx_scale] + 1
)
)
self.ckp.write_log(
'Total time: {:.2f}s\n'.format(timer_test.toc()), refresh=True
)
if not self.args.test_only:
self.ckp.save(self, epoch, is_best=(best[1][0] + 1 == epoch))
def prepare(self, l, volatile=False):
device = torch.device('cpu' if self.args.cpu else 'cuda')
def _prepare(tensor):
if self.args.precision == 'half': tensor = tensor.half()
return tensor.to(device)
return [_prepare(_l) for _l in l]
def terminate(self):
if self.args.test_only:
self.test()
return True
else:
epoch = self.scheduler.last_epoch + 1
return epoch >= self.args.epochs
