import datetime
import os
import time
import torch
import torch.utils.data
from torch import nn
import torchvision
from torchvision import transforms
import utils
try:
from apex import amp
except ImportError:
amp = None
def train_one_epoch(model, criterion, optimizer, data_loader, device, epoch, print_freq, apex=False):
model.train()
metric_logger = utils.MetricLogger(delimiter=" ")
metric_logger.add_meter('lr', utils.SmoothedValue(window_size=1, fmt='{value}'))
metric_logger.add_meter('img/s', utils.SmoothedValue(window_size=10, fmt='{value}'))
header = 'Epoch: [{}]'.format(epoch)
for image, target in metric_logger.log_every(data_loader, print_freq, header):
start_time = time.time()
image, target = image.to(device), target.to(device)
output = model(image)
loss = criterion(output, target)
optimizer.zero_grad()
if apex:
with amp.scale_loss(loss, optimizer) as scaled_loss:
scaled_loss.backward()
else:
loss.backward()
optimizer.step()
acc1, acc5 = utils.accuracy(output, target, topk=(1, 2))
batch_size = image.shape[0]
metric_logger.update(loss=loss.item(), lr=optimizer.param_groups[0]["lr"])
metric_logger.meters['acc1'].update(acc1.item(), n=batch_size)
metric_logger.meters['acc2'].update(acc5.item(), n=batch_size)
metric_logger.meters['img/s'].update(batch_size / (time.time() - start_time))
def evaluate(model, criterion, data_loader, device, print_freq=100):
model.eval()
metric_logger = utils.MetricLogger(delimiter=" ")
header = 'Test:'
with torch.no_grad():
for image, target in metric_logger.log_every(data_loader, print_freq, header):
image = image.to(device, non_blocking=True)
target = target.to(device, non_blocking=True)
output = model(image)
loss = criterion(output, target)
acc1, acc5 = utils.accuracy(output, target, topk=(1, 2))
# FIXME need to take into account that the datasets
# could have been padded in distributed setup
batch_size = image.shape[0]
metric_logger.update(loss=loss.item())
metric_logger.meters['acc1'].update(acc1.item(), n=batch_size)
metric_logger.meters['acc2'].update(acc5.item(), n=batch_size)
# gather the stats from all processes
metric_logger.synchronize_between_processes()
print(' * Acc@1 {top1.global_avg:.3f} Acc@2 {top5.global_avg:.3f}'
.format(top1=metric_logger.acc1, top5=metric_logger.acc2))
return metric_logger.acc1.global_avg
def _get_cache_path(filepath):
import hashlib
h = hashlib.sha1(filepath.encode()).hexdigest()
cache_path = os.path.join("~", ".torch", "vision", "datasets", "imagefolder", h[:10] + ".pt")
cache_path = os.path.expanduser(cache_path)
return cache_path
def load_data(traindir, valdir, cache_dataset, distributed):
# Data loading code
print("Loading data")
normalize = transforms.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
print("Loading training data")
st = time.time()
cache_path = _get_cache_path(traindir)
if cache_dataset and os.path.exists(cache_path):
# Attention, as the transforms are also cached!
print("Loading dataset_train from {}".format(cache_path))
dataset, _ = torch.load(cache_path)
else:
#dataset = torchvision.datasets.ImageFolder(
# traindir,
# transforms.Compose([
# transforms.RandomResizedCrop(224),
# transforms.RandomHorizontalFlip(),
# transforms.ToTensor(),
# normalize,
# ]))
dataset = utils.CSVDataset(
traindir,
transforms.Compose([
transforms.RandomResizedCrop(224),
transforms.RandomPerspective(),
transforms.RandomHorizontalFlip(),
transforms.RandomRotation(degrees=180),
transforms.ColorJitter(brightness=0.4, contrast=0.4, saturation=0.4, hue=0.0),
transforms.ToTensor(),
normalize,
]))
if cache_dataset:
print("Saving dataset_train to {}".format(cache_path))
utils.mkdir(os.path.dirname(cache_path))
utils.save_on_master((dataset, traindir), cache_path)
print("Took", time.time() - st)
print("Loading validation data")
cache_path = _get_cache_path(valdir)
if cache_dataset and os.path.exists(cache_path):
# Attention, as the transforms are also cached!
print("Loading dataset_test from {}".format(cache_path))
dataset_test, _ = torch.load(cache_path)
else:
#dataset_test = torchvision.datasets.ImageFolder(
# valdir,
# transforms.Compose([
# transforms.Resize(256),
# transforms.CenterCrop(224),
# transforms.ToTensor(),
# normalize,
# ]))
dataset_test = utils.CSVDataset(
valdir,
transforms.Compose([
transforms.Resize(256),
transforms.CenterCrop(224),
transforms.ToTensor(),
normalize,
]))
if cache_dataset:
print("Saving dataset_test to {}".format(cache_path))
utils.mkdir(os.path.dirname(cache_path))
utils.save_on_master((dataset_test, valdir), cache_path)
print("Creating data loaders")
if distributed:
train_sampler = torch.utils.data.distributed.DistributedSampler(dataset)
test_sampler = torch.utils.data.distributed.DistributedSampler(dataset_test)
else:
train_sampler = torch.utils.data.RandomSampler(dataset)
test_sampler = torch.utils.data.SequentialSampler(dataset_test)
return dataset, dataset_test, train_sampler, test_sampler
def main(args):
if args.apex and amp is None:
raise RuntimeError("Failed to import apex. Please install apex from https://www.github.com/nvidia/apex "
"to enable mixed-precision training.")
if args.output_dir:
utils.mkdir(args.output_dir)
utils.init_distributed_mode(args)
print(args)
device = torch.device(args.device)
torch.backends.cudnn.benchmark = True
#train_dir = os.path.join(args.data_path, 'train')
#val_dir = os.path.join(args.data_path, 'val')
train_dir = args.train_file
val_dir = args.val_file
dataset, dataset_test, train_sampler, test_sampler = load_data(train_dir, val_dir,
args.cache_dataset, args.distributed)
data_loader = torch.utils.data.DataLoader(
dataset, batch_size=args.batch_size,
sampler=train_sampler, num_workers=args.workers, pin_memory=True)
data_loader_test = torch.utils.data.DataLoader(
dataset_test, batch_size=args.batch_size,
sampler=test_sampler, num_workers=args.workers, pin_memory=True)
print("Creating model")
#model = torchvision.models.__dict__[args.model](pretrained=args.pretrained)
model = torchvision.models.densenet169(pretrained=args.pretrained)
# modify the last layer for objective task
num_ftrs = model.features.norm5.num_features
model.classifier = nn.Linear(num_ftrs, args.num_classes)
model.to(device)
if args.distributed and args.sync_bn:
model = torch.nn.SyncBatchNorm.convert_sync_batchnorm(model)
if args.focal_loss:
import pytorch_toolbelt.losses
criterion = pytorch_toolbelt.losses.FocalLoss()
else:
criterion = nn.CrossEntropyLoss()
optimizer = torch.optim.SGD(
model.parameters(), lr=args.lr, momentum=args.momentum, weight_decay=args.weight_decay)
if args.apex:
model, optimizer = amp.initialize(model, optimizer,
opt_level=args.apex_opt_level
)
lr_scheduler = torch.optim.lr_scheduler.StepLR(optimizer, step_size=args.lr_step_size, gamma=args.lr_gamma)
model_without_ddp = model
if args.distributed:
model = torch.nn.parallel.DistributedDataParallel(model, device_ids=[args.gpu])
model_without_ddp = model.module
if args.resume:
checkpoint = torch.load(args.resume, map_location='cpu')
model_without_ddp.load_state_dict(checkpoint['model'])
optimizer.load_state_dict(checkpoint['optimizer'])
lr_scheduler.load_state_dict(checkpoint['lr_scheduler'])
args.start_epoch = checkpoint['epoch'] + 1
if args.test_only:
evaluate(model, criterion, data_loader_test, device=device)
return
print("Start training")
start_time = time.time()
for epoch in range(args.start_epoch, args.epochs):
if args.distributed:
train_sampler.set_epoch(epoch)
train_one_epoch(model, criterion, optimizer, data_loader, device, epoch, args.print_freq, args.apex)
lr_scheduler.step()
evaluate(model, criterion, data_loader_test, device=device)
if args.output_dir:
checkpoint = {
'model': model_without_ddp.state_dict(),
'optimizer': optimizer.state_dict(),
'lr_scheduler': lr_scheduler.state_dict(),
'epoch': epoch,
'args': args}
utils.save_on_master(
checkpoint,
os.path.join(args.output_dir, 'model_{}.pth'.format(epoch)))
utils.save_on_master(
checkpoint,
os.path.join(args.output_dir, 'checkpoint.pth'))
total_time = time.time() - start_time
total_time_str = str(datetime.timedelta(seconds=int(total_time)))
print('Training time {}'.format(total_time_str))
def parse_args():
import argparse
parser = argparse.ArgumentParser(description='PyTorch Classification Training')
#parser.add_argument('--data-path', default='/datasets01/imagenet_full_size/061417/', help='dataset')
parser.add_argument('--train-file', help='training set')
parser.add_argument('--val-file', help='validation set')
parser.add_argument('--num-classes', help='number of classes for the objective task', type=int)
parser.add_argument(
"--focal-loss", help="Use focal loss",action="store_true")
#parser.add_argument('--model', default='resnet18', help='model')
parser.add_argument('--device', default='cuda', help='device')
parser.add_argument('-b', '--batch-size', default=32, type=int)
parser.add_argument('--epochs', default=90, type=int, metavar='N',
help='number of total epochs to run')
parser.add_argument('-j', '--workers', default=16, type=int, metavar='N',
help='number of data loading workers (default: 16)')
parser.add_argument('--lr', default=0.1, type=float, help='initial learning rate')
parser.add_argument('--momentum', default=0.9, type=float, metavar='M',
help='momentum')
parser.add_argument('--wd', '--weight-decay', default=1e-4, type=float,
metavar='W', help='weight decay (default: 1e-4)',
dest='weight_decay')
parser.add_argument('--lr-step-size', default=30, type=int, help='decrease lr every step-size epochs')
parser.add_argument('--lr-gamma', default=0.1, type=float, help='decrease lr by a factor of lr-gamma')
parser.add_argument('--print-freq', default=10, type=int, help='print frequency')
parser.add_argument('--output-dir', default='.', help='path where to save')
parser.add_argument('--resume', default='', help='resume from checkpoint')
parser.add_argument('--start-epoch', default=0, type=int, metavar='N',
help='start epoch')
parser.add_argument(
"--cache-dataset",
dest="cache_dataset",
help="Cache the datasets for quicker initialization. It also serializes the transforms",
action="store_true",
)
parser.add_argument(
"--sync-bn",
dest="sync_bn",
help="Use sync batch norm",
action="store_true",
)
parser.add_argument(
"--test-only",
dest="test_only",
help="Only test the model",
action="store_true",
)
parser.add_argument(
"--pretrained",
dest="pretrained",
help="Use pre-trained models from the modelzoo",
action="store_true",
)
# Mixed precision training parameters
parser.add_argument('--apex', action='store_true',
help='Use apex for mixed precision training')
parser.add_argument('--apex-opt-level', default='O1', type=str,
help='For apex mixed precision training'
'O0 for FP32 training, O1 for mixed precision training.'
'For further detail, see https://github.com/NVIDIA/apex/tree/master/examples/imagenet'
)
# distributed training parameters
parser.add_argument('--world-size', default=1, type=int,
help='number of distributed processes')
parser.add_argument('--dist-url', default='env://', help='url used to set up distributed training')
args = parser.parse_args()
return args
if __name__ == "__main__":
args = parse_args()
main(args)