def validate(val_loader: DataLoader, model: Classifier, args: argparse.Namespace) -> float:
batch_time = AverageMeter('Time', ':6.3f')
losses = AverageMeter('Loss', ':.4e')
top1 = AverageMeter('Acc@1', ':6.2f')
top5 = AverageMeter('Acc@5', ':6.2f')
progress = ProgressMeter(
len(val_loader),
[batch_time, losses, top1, top5],
prefix='Test: ')
# switch to evaluate mode
model.eval()
if args.per_class_eval:
classes = val_loader.dataset.classes
confmat = ConfusionMatrix(len(classes))
else:
confmat = None
with torch.no_grad():
end = time.time()
for i, (images, target) in enumerate(val_loader):
images = images.to(device)
target = target.to(device)
# compute output
output, _ = model(images)
loss = F.cross_entropy(output, target)
# measure accuracy and record loss
acc1, acc5 = accuracy(output, target, topk=(1, 5))
if confmat:
confmat.update(target, output.argmax(1))
losses.update(loss.item(), images.size(0))
top1.update(acc1.item(), images.size(0))
top5.update(acc5.item(), images.size(0))
# measure elapsed time
batch_time.update(time.time() - end)
end = time.time()
if i % args.print_freq == 0:
progress.display(i)
print(' * Acc@1 {top1.avg:.3f} Acc@5 {top5.avg:.3f}'
.format(top1=top1, top5=top5))
if confmat:
print(confmat.format(classes))
return top1.avg
def validate(val_loader: DataLoader, model: Classifier,
args: argparse.Namespace) -> float:
batch_time = AverageMeter('Time', ':6.3f')
classes = val_loader.dataset.classes
confmat = ConfusionMatrix(len(classes))
progress = ProgressMeter(len(val_loader), [batch_time], prefix='Test: ')
# switch to evaluate mode
model.eval()
with torch.no_grad():
end = time.time()
for i, (images, target) in enumerate(val_loader):
images = images.to(device)
target = target.to(device)
# compute output
output, _ = model(images)
softmax_output = F.softmax(output, dim=1)
softmax_output[:, -1] = args.threshold
# measure accuracy and record loss
confmat.update(target, softmax_output.argmax(1))
# measure elapsed time
batch_time.update(time.time() - end)
end = time.time()
if i % args.print_freq == 0:
progress.display(i)
acc_global, accs, iu = confmat.compute()
all_acc = torch.mean(accs).item() * 100
known = torch.mean(accs[:-1]).item() * 100
unknown = accs[-1].item() * 100
h_score = 2 * known * unknown / (known + unknown)
if args.per_class_eval:
print(confmat.format(classes))
print(
' * All {all:.3f} Known {known:.3f} Unknown {unknown:.3f} H-score {h_score:.3f}'
.format(all=all_acc, known=known, unknown=unknown,
h_score=h_score))
return h_score
def main(args: argparse.Namespace):
logger = CompleteLogger(args.log, args.phase)
print(args)
if args.seed is not None:
random.seed(args.seed)
torch.manual_seed(args.seed)
cudnn.deterministic = True
warnings.warn('You have chosen to seed training. '
'This will turn on the CUDNN deterministic setting, '
'which can slow down your training considerably! '
'You may see unexpected behavior when restarting '
'from checkpoints.')
cudnn.benchmark = True
# Data loading code
normalize = T.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
train_transform = T.Compose([
ResizeImage(256),
T.RandomResizedCrop(224),
T.RandomHorizontalFlip(),
T.ToTensor(), normalize
])
val_transform = T.Compose(
[ResizeImage(256),
T.CenterCrop(224),
T.ToTensor(), normalize])
dataset = datasets.__dict__[args.data]
train_dataset = dataset(root=args.root,
split='train',
sample_rate=args.sample_rate,
download=True,
transform=train_transform)
train_loader = DataLoader(train_dataset,
batch_size=args.batch_size,
shuffle=True,
num_workers=args.workers,
drop_last=True)
val_dataset = dataset(root=args.root,
split='test',
sample_rate=100,
download=True,
transform=val_transform)
val_loader = DataLoader(val_dataset,
batch_size=args.batch_size,
shuffle=False,
num_workers=args.workers)
train_iter = ForeverDataIterator(train_loader)
# create model
print("=> using pre-trained model '{}'".format(args.arch))
backbone = models.__dict__[args.arch](pretrained=True)
backbone_source = models.__dict__[args.arch](pretrained=True)
num_classes = train_dataset.num_classes
classifier = Classifier(backbone, num_classes).to(device)
source_classifier = Classifier(
backbone_source,
head=backbone_source.copy_head(),
num_classes=backbone_source.fc.out_features).to(device)
for param in source_classifier.parameters():
param.requires_grad = False
source_classifier.eval()
# define optimizer and lr scheduler
optimizer = SGD(classifier.get_parameters(args.lr),
momentum=args.momentum,
weight_decay=args.wd,
nesterov=True)
lr_scheduler = torch.optim.lr_scheduler.MultiStepLR(optimizer,
args.lr_decay_epochs,
gamma=args.lr_gamma)
# resume from the best checkpoint
if args.phase == 'test':
checkpoint = torch.load(logger.get_checkpoint_path('best'),
map_location='cpu')
classifier.load_state_dict(checkpoint)
acc1 = validate(val_loader, classifier, args)
print(acc1)
return
# create intermediate layer getter
if args.arch == 'resnet50':
return_layers = [
'backbone.layer1.2.conv3', 'backbone.layer2.3.conv3',
'backbone.layer3.5.conv3', 'backbone.layer4.2.conv3'
]
elif args.arch == 'resnet101':
return_layers = [
'backbone.layer1.2.conv3', 'backbone.layer2.3.conv3',
'backbone.layer3.5.conv3', 'backbone.layer4.2.conv3'
]
else:
raise NotImplementedError(args.arch)
source_getter = IntermediateLayerGetter(source_classifier,
return_layers=return_layers)
target_getter = IntermediateLayerGetter(classifier,
return_layers=return_layers)
# get regularization
if args.regularization_type == 'l2_sp':
backbone_regularization = SPRegularization(source_classifier.backbone,
classifier.backbone)
elif args.regularization_type == 'feature_map':
backbone_regularization = BehavioralRegularization()
elif args.regularization_type == 'attention_feature_map':
attention_file = os.path.join(logger.root, args.attention_file)
if not os.path.exists(attention_file):
attention = calculate_channel_attention(train_dataset,
return_layers, args)
torch.save(attention, attention_file)
else:
print("Loading channel attention from", attention_file)
attention = torch.load(attention_file)
attention = [a.to(device) for a in attention]
backbone_regularization = AttentionBehavioralRegularization(attention)
else:
raise NotImplementedError(args.regularization_type)
head_regularization = L2Regularization(
nn.ModuleList([classifier.head, classifier.bottleneck]))
# start training
best_acc1 = 0.0
for epoch in range(args.epochs):
print(lr_scheduler.get_lr())
# train for one epoch
train(train_iter, classifier, backbone_regularization,
head_regularization, target_getter, source_getter, optimizer,
epoch, args)
lr_scheduler.step()
# evaluate on validation set
acc1 = validate(val_loader, classifier, args)
# remember best acc@1 and save checkpoint
torch.save(classifier.state_dict(),
logger.get_checkpoint_path('latest'))
if acc1 > best_acc1:
shutil.copy(logger.get_checkpoint_path('latest'),
logger.get_checkpoint_path('best'))
best_acc1 = max(acc1, best_acc1)
print("best_acc1 = {:3.1f}".format(best_acc1))
logger.close()
def calculate_channel_attention(dataset, return_layers, args):
backbone = models.__dict__[args.arch](pretrained=True)
classifier = Classifier(backbone, dataset.num_classes).to(device)
optimizer = SGD(classifier.get_parameters(args.lr),
momentum=args.momentum,
weight_decay=args.wd,
nesterov=True)
data_loader = DataLoader(dataset,
batch_size=args.attention_batch_size,
shuffle=True,
num_workers=args.workers,
drop_last=False)
lr_scheduler = torch.optim.lr_scheduler.ExponentialLR(
optimizer,
gamma=math.exp(math.log(0.1) / args.attention_lr_decay_epochs))
criterion = nn.CrossEntropyLoss()
channel_weights = []
for layer_id, name in enumerate(return_layers):
layer = get_attribute(classifier, name)
layer_channel_weight = [0] * layer.out_channels
channel_weights.append(layer_channel_weight)
# train the classifier
classifier.train()
classifier.backbone.requires_grad = False
print("Pretrain a classifier to calculate channel attention.")
for epoch in range(args.attention_epochs):
losses = AverageMeter('Loss', ':3.2f')
cls_accs = AverageMeter('Cls Acc', ':3.1f')
progress = ProgressMeter(len(data_loader), [losses, cls_accs],
prefix="Epoch: [{}]".format(epoch))
for i, data in enumerate(data_loader):
inputs, labels = data
inputs = inputs.to(device)
labels = labels.to(device)
outputs, _ = classifier(inputs)
loss = criterion(outputs, labels)
optimizer.zero_grad()
loss.backward()
optimizer.step()
cls_acc = accuracy(outputs, labels)[0]
losses.update(loss.item(), inputs.size(0))
cls_accs.update(cls_acc.item(), inputs.size(0))
if i % args.print_freq == 0:
progress.display(i)
lr_scheduler.step()
# calculate the channel attention
print('Calculating channel attention.')
classifier.eval()
if args.attention_iteration_limit > 0:
total_iteration = min(len(data_loader), args.attention_iteration_limit)
else:
total_iteration = len(args.data_loader)
progress = ProgressMeter(total_iteration, [], prefix="Iteration: ")
for i, data in enumerate(data_loader):
if i >= total_iteration:
break
inputs, labels = data
inputs = inputs.to(device)
labels = labels.to(device)
outputs, _ = classifier(inputs)
loss_0 = criterion(outputs, labels)
progress.display(i)
for layer_id, name in enumerate(tqdm(return_layers)):
layer = get_attribute(classifier, name)
for j in range(layer.out_channels):
tmp = classifier.state_dict()[name + '.weight'][j, ].clone()
classifier.state_dict()[name + '.weight'][j, ] = 0.0
outputs, _ = classifier(inputs)
loss_1 = criterion(outputs, labels)
difference = loss_1 - loss_0
difference = difference.detach().cpu().numpy().item()
history_value = channel_weights[layer_id][j]
channel_weights[layer_id][j] = 1.0 * (i * history_value +
difference) / (i + 1)
classifier.state_dict()[name + '.weight'][j, ] = tmp
channel_attention = []
for weight in channel_weights:
weight = np.array(weight)
weight = (weight - np.mean(weight)) / np.std(weight)
weight = torch.from_numpy(weight).float().to(device)
channel_attention.append(F.softmax(weight / 5).detach())
return channel_attention
