def run_test(batch_size, img_name, seg_name, output_dir, device="cuda:0"):
ds = ImageDataset([img_name], [seg_name], transform=AddChannel(), seg_transform=AddChannel(), image_only=False)
loader = DataLoader(ds, batch_size=1, pin_memory=torch.cuda.is_available())
net = UNet(
dimensions=3, in_channels=1, out_channels=1, channels=(4, 8, 16, 32), strides=(2, 2, 2), num_res_units=2
).to(device)
roi_size = (16, 32, 48)
sw_batch_size = batch_size
def _sliding_window_processor(_engine, batch):
img, seg, meta_data = batch
with eval_mode(net):
seg_probs = sliding_window_inference(img.to(device), roi_size, sw_batch_size, net, device=device)
return predict_segmentation(seg_probs)
infer_engine = Engine(_sliding_window_processor)
SegmentationSaver(
output_dir=output_dir, output_ext=".nii.gz", output_postfix="seg", batch_transform=lambda x: x[2]
).attach(infer_engine)
infer_engine.run(loader)
basename = os.path.basename(img_name)[: -len(".nii.gz")]
saved_name = os.path.join(output_dir, basename, f"{basename}_seg.nii.gz")
return saved_name
def test_use_case(self):
with tempfile.TemporaryDirectory() as tempdir:
img_ = nib.Nifti1Image(np.random.randint(0, 2, size=(20, 20, 20)),
np.eye(4))
seg_ = nib.Nifti1Image(np.random.randint(0, 2, size=(20, 20, 20)),
np.eye(4))
img_name, seg_name = os.path.join(tempdir,
"img.nii.gz"), os.path.join(
tempdir, "seg.nii.gz")
nib.save(img_, img_name)
nib.save(seg_, seg_name)
img_list, seg_list = [img_name], [seg_name]
img_xform = _TestCompose([
EnsureChannelFirst(),
Spacing(pixdim=(1.5, 1.5, 3.0)),
RandAdjustContrast()
])
seg_xform = _TestCompose([
EnsureChannelFirst(),
Spacing(pixdim=(1.5, 1.5, 3.0), mode="nearest")
])
img_dataset = ImageDataset(
image_files=img_list,
seg_files=seg_list,
transform=img_xform,
seg_transform=seg_xform,
image_only=False,
transform_with_metadata=True,
)
self.assertTupleEqual(img_dataset[0][0].shape, (1, 14, 14, 7))
self.assertTupleEqual(img_dataset[0][1].shape, (1, 14, 14, 7))
def main(tempdir):
config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
print(f"generating synthetic data to {tempdir} (this may take a while)")
for i in range(5):
im, seg = create_test_image_3d(128, 128, 128, num_seg_classes=1)
n = nib.Nifti1Image(im, np.eye(4))
nib.save(n, os.path.join(tempdir, f"im{i:d}.nii.gz"))
n = nib.Nifti1Image(seg, np.eye(4))
nib.save(n, os.path.join(tempdir, f"seg{i:d}.nii.gz"))
images = sorted(glob(os.path.join(tempdir, "im*.nii.gz")))
segs = sorted(glob(os.path.join(tempdir, "seg*.nii.gz")))
# define transforms for image and segmentation
imtrans = Compose([ScaleIntensity(), AddChannel(), ToTensor()])
segtrans = Compose([AddChannel(), ToTensor()])
val_ds = ImageDataset(images, segs, transform=imtrans, seg_transform=segtrans, image_only=False)
# sliding window inference for one image at every iteration
val_loader = DataLoader(val_ds, batch_size=1, num_workers=1, pin_memory=torch.cuda.is_available())
dice_metric = DiceMetric(include_background=True, reduction="mean")
post_trans = Compose([Activations(sigmoid=True), AsDiscrete(threshold_values=True)])
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = UNet(
dimensions=3,
in_channels=1,
out_channels=1,
channels=(16, 32, 64, 128, 256),
strides=(2, 2, 2, 2),
num_res_units=2,
).to(device)
model.load_state_dict(torch.load("best_metric_model_segmentation3d_array.pth"))
model.eval()
with torch.no_grad():
metric_sum = 0.0
metric_count = 0
saver = NiftiSaver(output_dir="./output")
for val_data in val_loader:
val_images, val_labels = val_data[0].to(device), val_data[1].to(device)
# define sliding window size and batch size for windows inference
roi_size = (96, 96, 96)
sw_batch_size = 4
val_outputs = sliding_window_inference(val_images, roi_size, sw_batch_size, model)
val_outputs = post_trans(val_outputs)
value, _ = dice_metric(y_pred=val_outputs, y=val_labels)
metric_count += len(value)
metric_sum += value.item() * len(value)
saver.save_batch(val_outputs, val_data[2])
metric = metric_sum / metric_count
print("evaluation metric:", metric)
def main():
monai.config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
# IXI dataset as a demo, downloadable from https://brain-development.org/ixi-dataset/
images = [
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI607-Guys-1097-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI175-HH-1570-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI385-HH-2078-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI344-Guys-0905-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI409-Guys-0960-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI584-Guys-1129-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI253-HH-1694-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI092-HH-1436-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI574-IOP-1156-T1.nii.gz"]),
os.sep.join(["workspace", "data", "medical", "ixi", "IXI-T1", "IXI585-Guys-1130-T1.nii.gz"]),
]
# 2 binary labels for gender classification: man and woman
labels = np.array([0, 0, 1, 0, 1, 0, 1, 0, 1, 0], dtype=np.int64)
# Define transforms for image
val_transforms = Compose([ScaleIntensity(), AddChannel(), Resize((96, 96, 96)), ToTensor()])
# Define image dataset
val_ds = ImageDataset(image_files=images, labels=labels, transform=val_transforms, image_only=False)
# create a validation data loader
val_loader = DataLoader(val_ds, batch_size=2, num_workers=4, pin_memory=torch.cuda.is_available())
# Create DenseNet121
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = monai.networks.nets.DenseNet121(spatial_dims=3, in_channels=1, out_channels=2).to(device)
model.load_state_dict(torch.load("best_metric_model_classification3d_array.pth"))
model.eval()
with torch.no_grad():
num_correct = 0.0
metric_count = 0
saver = CSVSaver(output_dir="./output")
for val_data in val_loader:
val_images, val_labels = val_data[0].to(device), val_data[1].to(device)
val_outputs = model(val_images).argmax(dim=1)
value = torch.eq(val_outputs, val_labels)
metric_count += len(value)
num_correct += value.sum().item()
saver.save_batch(val_outputs, val_data[2])
metric = num_correct / metric_count
print("evaluation metric:", metric)
saver.finalize()
def run_test(batch_size, img_name, seg_name, output_dir, device="cuda:0"):
ds = ImageDataset([img_name], [seg_name],
transform=AddChannel(),
seg_transform=AddChannel(),
image_only=True)
loader = DataLoader(ds, batch_size=1, pin_memory=torch.cuda.is_available())
net = UNet(spatial_dims=3,
in_channels=1,
out_channels=1,
channels=(4, 8, 16, 32),
strides=(2, 2, 2),
num_res_units=2).to(device)
roi_size = (16, 32, 48)
sw_batch_size = batch_size
saver = SaveImage(output_dir=output_dir,
output_ext=".nii.gz",
output_postfix="seg")
def _sliding_window_processor(_engine, batch):
img = batch[0] # first item from ImageDataset is the input image
with eval_mode(net):
seg_probs = sliding_window_inference(img.to(device),
roi_size,
sw_batch_size,
net,
device=device)
return predict_segmentation(seg_probs)
def save_func(engine):
if pytorch_after(1, 9, 1):
for m in engine.state.output:
saver(m)
else:
saver(engine.state.output[0])
infer_engine = Engine(_sliding_window_processor)
infer_engine.add_event_handler(Events.ITERATION_COMPLETED, save_func)
infer_engine.run(loader)
basename = os.path.basename(img_name)[:-len(".nii.gz")]
saved_name = os.path.join(output_dir, basename, f"{basename}_seg.nii.gz")
return saved_name
def main(tempdir):
config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
print(f"generating synthetic data to {tempdir} (this may take a while)")
for i in range(5):
im, seg = create_test_image_3d(128, 128, 128, num_seg_classes=1)
n = nib.Nifti1Image(im, np.eye(4))
nib.save(n, os.path.join(tempdir, f"im{i:d}.nii.gz"))
n = nib.Nifti1Image(seg, np.eye(4))
nib.save(n, os.path.join(tempdir, f"seg{i:d}.nii.gz"))
images = sorted(glob(os.path.join(tempdir, "im*.nii.gz")))
segs = sorted(glob(os.path.join(tempdir, "seg*.nii.gz")))
# define transforms for image and segmentation
imtrans = Compose([ScaleIntensity(), AddChannel(), ToTensor()])
segtrans = Compose([AddChannel(), ToTensor()])
ds = ImageDataset(images,
segs,
transform=imtrans,
seg_transform=segtrans,
image_only=False)
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
net = UNet(
dimensions=3,
in_channels=1,
out_channels=1,
channels=(16, 32, 64, 128, 256),
strides=(2, 2, 2, 2),
num_res_units=2,
).to(device)
# define sliding window size and batch size for windows inference
roi_size = (96, 96, 96)
sw_batch_size = 4
post_trans = Compose(
[Activations(sigmoid=True),
AsDiscrete(threshold_values=True)])
def _sliding_window_processor(engine, batch):
net.eval()
with torch.no_grad():
val_images, val_labels = batch[0].to(device), batch[1].to(device)
seg_probs = sliding_window_inference(val_images, roi_size,
sw_batch_size, net)
seg_probs = post_trans(seg_probs)
return seg_probs, val_labels
evaluator = Engine(_sliding_window_processor)
# add evaluation metric to the evaluator engine
MeanDice().attach(evaluator, "Mean_Dice")
# StatsHandler prints loss at every iteration and print metrics at every epoch,
# we don't need to print loss for evaluator, so just print metrics, user can also customize print functions
val_stats_handler = StatsHandler(
name="evaluator",
output_transform=lambda x:
None, # no need to print loss value, so disable per iteration output
)
val_stats_handler.attach(evaluator)
# for the array data format, assume the 3rd item of batch data is the meta_data
file_saver = SegmentationSaver(
output_dir="tempdir",
output_ext=".nii.gz",
output_postfix="seg",
name="evaluator",
batch_transform=lambda x: x[2],
output_transform=lambda output: output[0],
)
file_saver.attach(evaluator)
# the model was trained by "unet_training_array" example
ckpt_saver = CheckpointLoader(
load_path="./runs_array/net_checkpoint_100.pt", load_dict={"net": net})
ckpt_saver.attach(evaluator)
# sliding window inference for one image at every iteration
loader = DataLoader(ds,
batch_size=1,
num_workers=1,
pin_memory=torch.cuda.is_available())
state = evaluator.run(loader)
print(state)
def main(tempdir):
config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
print(f"generating synthetic data to {tempdir} (this may take a while)")
for i in range(5):
im, seg = create_test_image_3d(128, 128, 128, num_seg_classes=1)
n = nib.Nifti1Image(im, np.eye(4))
nib.save(n, os.path.join(tempdir, f"im{i:d}.nii.gz"))
n = nib.Nifti1Image(seg, np.eye(4))
nib.save(n, os.path.join(tempdir, f"seg{i:d}.nii.gz"))
images = sorted(glob(os.path.join(tempdir, "im*.nii.gz")))
segs = sorted(glob(os.path.join(tempdir, "seg*.nii.gz")))
# define transforms for image and segmentation
imtrans = Compose([ScaleIntensity(), AddChannel(), EnsureType()])
segtrans = Compose([AddChannel(), EnsureType()])
val_ds = ImageDataset(images,
segs,
transform=imtrans,
seg_transform=segtrans,
image_only=False)
# sliding window inference for one image at every iteration
val_loader = DataLoader(val_ds,
batch_size=1,
num_workers=1,
pin_memory=torch.cuda.is_available())
dice_metric = DiceMetric(include_background=True,
reduction="mean",
get_not_nans=False)
post_trans = Compose(
[EnsureType(),
Activations(sigmoid=True),
AsDiscrete(threshold=0.5)])
saver = SaveImage(output_dir="./output",
output_ext=".nii.gz",
output_postfix="seg")
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = UNet(
spatial_dims=3,
in_channels=1,
out_channels=1,
channels=(16, 32, 64, 128, 256),
strides=(2, 2, 2, 2),
num_res_units=2,
).to(device)
model.load_state_dict(
torch.load("best_metric_model_segmentation3d_array.pth"))
model.eval()
with torch.no_grad():
for val_data in val_loader:
val_images, val_labels = val_data[0].to(device), val_data[1].to(
device)
# define sliding window size and batch size for windows inference
roi_size = (96, 96, 96)
sw_batch_size = 4
val_outputs = sliding_window_inference(val_images, roi_size,
sw_batch_size, model)
val_outputs = [post_trans(i) for i in decollate_batch(val_outputs)]
val_labels = decollate_batch(val_labels)
meta_data = decollate_batch(val_data[2])
# compute metric for current iteration
dice_metric(y_pred=val_outputs, y=val_labels)
for val_output, data in zip(val_outputs, meta_data):
saver(val_output, data)
# aggregate the final mean dice result
print("evaluation metric:", dice_metric.aggregate().item())
# reset the status
dice_metric.reset()
def main():
monai.config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
# IXI dataset as a demo, downloadable from https://brain-development.org/ixi-dataset/
images = [
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI314-IOP-0889-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI249-Guys-1072-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI609-HH-2600-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI173-HH-1590-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI020-Guys-0700-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI342-Guys-0909-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI134-Guys-0780-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI577-HH-2661-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI066-Guys-0731-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI130-HH-1528-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI607-Guys-1097-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI175-HH-1570-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI385-HH-2078-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI344-Guys-0905-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI409-Guys-0960-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI584-Guys-1129-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI253-HH-1694-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI092-HH-1436-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI574-IOP-1156-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI585-Guys-1130-T1.nii.gz"
]),
]
# 2 binary labels for gender classification: man and woman
labels = np.array(
[0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0],
dtype=np.int64)
# Define transforms
train_transforms = Compose([
ScaleIntensity(),
AddChannel(),
Resize((96, 96, 96)),
RandRotate90(),
ToTensor()
])
val_transforms = Compose(
[ScaleIntensity(),
AddChannel(),
Resize((96, 96, 96)),
ToTensor()])
# Define image dataset, data loader
check_ds = ImageDataset(image_files=images,
labels=labels,
transform=train_transforms)
check_loader = DataLoader(check_ds,
batch_size=2,
num_workers=2,
pin_memory=torch.cuda.is_available())
im, label = monai.utils.misc.first(check_loader)
print(type(im), im.shape, label)
# create a training data loader
train_ds = ImageDataset(image_files=images[:10],
labels=labels[:10],
transform=train_transforms)
train_loader = DataLoader(train_ds,
batch_size=2,
shuffle=True,
num_workers=2,
pin_memory=torch.cuda.is_available())
# create a validation data loader
val_ds = ImageDataset(image_files=images[-10:],
labels=labels[-10:],
transform=val_transforms)
val_loader = DataLoader(val_ds,
batch_size=2,
num_workers=2,
pin_memory=torch.cuda.is_available())
# Create DenseNet121, CrossEntropyLoss and Adam optimizer
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = monai.networks.nets.DenseNet121(spatial_dims=3,
in_channels=1,
out_channels=2).to(device)
loss_function = torch.nn.CrossEntropyLoss()
optimizer = torch.optim.Adam(model.parameters(), 1e-5)
# start a typical PyTorch training
val_interval = 2
best_metric = -1
best_metric_epoch = -1
epoch_loss_values = list()
metric_values = list()
writer = SummaryWriter()
for epoch in range(5):
print("-" * 10)
print(f"epoch {epoch + 1}/{5}")
model.train()
epoch_loss = 0
step = 0
for batch_data in train_loader:
step += 1
inputs, labels = batch_data[0].to(device), batch_data[1].to(device)
optimizer.zero_grad()
outputs = model(inputs)
loss = loss_function(outputs, labels)
loss.backward()
optimizer.step()
epoch_loss += loss.item()
epoch_len = len(train_ds) // train_loader.batch_size
print(f"{step}/{epoch_len}, train_loss: {loss.item():.4f}")
writer.add_scalar("train_loss", loss.item(),
epoch_len * epoch + step)
epoch_loss /= step
epoch_loss_values.append(epoch_loss)
print(f"epoch {epoch + 1} average loss: {epoch_loss:.4f}")
if (epoch + 1) % val_interval == 0:
model.eval()
with torch.no_grad():
num_correct = 0.0
metric_count = 0
for val_data in val_loader:
val_images, val_labels = val_data[0].to(
device), val_data[1].to(device)
val_outputs = model(val_images)
value = torch.eq(val_outputs.argmax(dim=1), val_labels)
metric_count += len(value)
num_correct += value.sum().item()
metric = num_correct / metric_count
metric_values.append(metric)
if metric > best_metric:
best_metric = metric
best_metric_epoch = epoch + 1
torch.save(model.state_dict(),
"best_metric_model_classification3d_array.pth")
print("saved new best metric model")
print(
"current epoch: {} current accuracy: {:.4f} best accuracy: {:.4f} at epoch {}"
.format(epoch + 1, metric, best_metric, best_metric_epoch))
writer.add_scalar("val_accuracy", metric, epoch + 1)
print(
f"train completed, best_metric: {best_metric:.4f} at epoch: {best_metric_epoch}"
)
writer.close()
def test_dataset(self):
with tempfile.TemporaryDirectory() as tempdir:
full_names, ref_data = [], []
for filename in FILENAMES:
test_image = np.random.randint(0, 2, size=(4, 4, 4))
ref_data.append(test_image)
save_path = os.path.join(tempdir, filename)
full_names.append(save_path)
nib.save(nib.Nifti1Image(test_image, np.eye(4)), save_path)
# default loading no meta
dataset = ImageDataset(full_names)
for d, ref in zip(dataset, ref_data):
np.testing.assert_allclose(d, ref, atol=1e-3)
# loading no meta, int
dataset = ImageDataset(full_names, dtype=np.float16)
for d, _ in zip(dataset, ref_data):
self.assertEqual(d.dtype, np.float16)
# loading with meta, no transform
dataset = ImageDataset(full_names, image_only=False)
for d_tuple, ref in zip(dataset, ref_data):
d, meta = d_tuple
np.testing.assert_allclose(d, ref, atol=1e-3)
np.testing.assert_allclose(meta["original_affine"], np.eye(4))
# loading image/label, no meta
dataset = ImageDataset(full_names,
seg_files=full_names,
image_only=True)
for d_tuple, ref in zip(dataset, ref_data):
img, seg = d_tuple
np.testing.assert_allclose(img, ref, atol=1e-3)
np.testing.assert_allclose(seg, ref, atol=1e-3)
# loading image/label, no meta
dataset = ImageDataset(full_names,
transform=lambda x: x + 1,
image_only=True)
for d, ref in zip(dataset, ref_data):
np.testing.assert_allclose(d, ref + 1, atol=1e-3)
# set seg transform, but no seg_files
with self.assertRaises(RuntimeError):
dataset = ImageDataset(full_names,
seg_transform=lambda x: x + 1,
image_only=True)
_ = dataset[0]
# set seg transform, but no seg_files
with self.assertRaises(RuntimeError):
dataset = ImageDataset(full_names,
seg_transform=lambda x: x + 1,
image_only=True)
_ = dataset[0]
# loading image/label, with meta
dataset = ImageDataset(
full_names,
transform=lambda x: x + 1,
seg_files=full_names,
seg_transform=lambda x: x + 2,
image_only=False,
)
for d_tuple, ref in zip(dataset, ref_data):
img, seg, meta = d_tuple
np.testing.assert_allclose(img, ref + 1, atol=1e-3)
np.testing.assert_allclose(seg, ref + 2, atol=1e-3)
np.testing.assert_allclose(meta["original_affine"],
np.eye(4),
atol=1e-3)
# loading image/label, with meta
dataset = ImageDataset(full_names,
transform=lambda x: x + 1,
seg_files=full_names,
labels=[1, 2, 3],
image_only=False)
for idx, (d_tuple, ref) in enumerate(zip(dataset, ref_data)):
img, seg, label, meta = d_tuple
np.testing.assert_allclose(img, ref + 1, atol=1e-3)
np.testing.assert_allclose(seg, ref, atol=1e-3)
np.testing.assert_allclose(idx + 1, label)
np.testing.assert_allclose(meta["original_affine"],
np.eye(4),
atol=1e-3)
# loading image/label, with sync. transform
dataset = ImageDataset(full_names,
transform=RandTest(),
seg_files=full_names,
seg_transform=RandTest(),
image_only=False)
for d_tuple, ref in zip(dataset, ref_data):
img, seg, meta = d_tuple
np.testing.assert_allclose(img, seg, atol=1e-3)
self.assertTrue(not np.allclose(img, ref))
np.testing.assert_allclose(meta["original_affine"],
np.eye(4),
atol=1e-3)
def test_dataset(self):
with tempfile.TemporaryDirectory() as tempdir:
full_names, ref_data = [], []
for filename in FILENAMES:
test_image = np.random.randint(0, 2, size=(4, 4, 4))
ref_data.append(test_image)
save_path = os.path.join(tempdir, filename)
full_names.append(save_path)
nib.save(nib.Nifti1Image(test_image, np.eye(4)), save_path)
# default loading no meta
dataset = ImageDataset(full_names)
for d, ref in zip(dataset, ref_data):
np.testing.assert_allclose(d, ref, atol=1e-3)
# loading no meta, int
dataset = ImageDataset(full_names, dtype=np.float16)
for d, _ in zip(dataset, ref_data):
self.assertEqual(d.dtype, np.float16)
# loading with meta, no transform
dataset = ImageDataset(full_names, image_only=False)
for d_tuple, ref in zip(dataset, ref_data):
d, meta = d_tuple
np.testing.assert_allclose(d, ref, atol=1e-3)
np.testing.assert_allclose(meta["original_affine"], np.eye(4))
# loading image/label, no meta
dataset = ImageDataset(full_names, seg_files=full_names, image_only=True)
for d_tuple, ref in zip(dataset, ref_data):
img, seg = d_tuple
np.testing.assert_allclose(img, ref, atol=1e-3)
np.testing.assert_allclose(seg, ref, atol=1e-3)
# loading image/label, no meta
dataset = ImageDataset(full_names, transform=lambda x: x + 1, image_only=True)
for d, ref in zip(dataset, ref_data):
np.testing.assert_allclose(d, ref + 1, atol=1e-3)
# loading image/label, with meta
dataset = ImageDataset(
full_names,
transform=lambda x: x + 1,
seg_files=full_names,
seg_transform=lambda x: x + 2,
image_only=False,
)
for d_tuple, ref in zip(dataset, ref_data):
img, seg, meta, seg_meta = d_tuple
np.testing.assert_allclose(img, ref + 1, atol=1e-3)
np.testing.assert_allclose(seg, ref + 2, atol=1e-3)
np.testing.assert_allclose(meta["original_affine"], np.eye(4), atol=1e-3)
np.testing.assert_allclose(seg_meta["original_affine"], np.eye(4), atol=1e-3)
# loading image/label, with meta
dataset = ImageDataset(
image_files=full_names,
seg_files=full_names,
labels=[1, 2, 3],
transform=lambda x: x + 1,
label_transform=Compose(
[
ToNumpy(),
MapLabelValue(orig_labels=[1, 2, 3], target_labels=[30.0, 20.0, 10.0], dtype=np.float32),
]
),
image_only=False,
)
for idx, (d_tuple, ref) in enumerate(zip(dataset, ref_data)):
img, seg, label, meta, seg_meta = d_tuple
np.testing.assert_allclose(img, ref + 1, atol=1e-3)
np.testing.assert_allclose(seg, ref, atol=1e-3)
# test label_transform
np.testing.assert_allclose((3 - idx) * 10.0, label)
self.assertTrue(isinstance(label, np.ndarray))
self.assertEqual(label.dtype, np.float32)
np.testing.assert_allclose(meta["original_affine"], np.eye(4), atol=1e-3)
np.testing.assert_allclose(seg_meta["original_affine"], np.eye(4), atol=1e-3)
# loading image/label, with sync. transform
dataset = ImageDataset(
full_names, transform=RandTest(), seg_files=full_names, seg_transform=RandTest(), image_only=False
)
for d_tuple, ref in zip(dataset, ref_data):
img, seg, meta, seg_meta = d_tuple
np.testing.assert_allclose(img, seg, atol=1e-3)
self.assertTrue(not np.allclose(img, ref))
np.testing.assert_allclose(meta["original_affine"], np.eye(4), atol=1e-3)
def main():
monai.config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
# IXI dataset as a demo, downloadable from https://brain-development.org/ixi-dataset/
images = [
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI607-Guys-1097-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI175-HH-1570-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI385-HH-2078-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI344-Guys-0905-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI409-Guys-0960-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI584-Guys-1129-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI253-HH-1694-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI092-HH-1436-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI574-IOP-1156-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI585-Guys-1130-T1.nii.gz"
]),
]
# 2 binary labels for gender classification: man and woman
labels = np.array([0, 0, 1, 0, 1, 0, 1, 0, 1, 0], dtype=np.int64)
# define transforms for image
val_transforms = Compose(
[ScaleIntensity(),
AddChannel(),
Resize((96, 96, 96)),
ToTensor()])
# define image dataset
val_ds = ImageDataset(image_files=images,
labels=labels,
transform=val_transforms,
image_only=False)
# create DenseNet121
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
net = monai.networks.nets.densenet.densenet121(spatial_dims=3,
in_channels=1,
out_channels=2).to(device)
metric_name = "Accuracy"
# add evaluation metric to the evaluator engine
val_metrics = {metric_name: Accuracy()}
def prepare_batch(batch, device=None, non_blocking=False):
return _prepare_batch((batch[0], batch[1]), device, non_blocking)
# Ignite evaluator expects batch=(img, label) and returns output=(y_pred, y) at every iteration,
# user can add output_transform to return other values
evaluator = create_supervised_evaluator(net,
val_metrics,
device,
True,
prepare_batch=prepare_batch)
# add stats event handler to print validation stats via evaluator
val_stats_handler = StatsHandler(
name="evaluator",
output_transform=lambda x:
None, # no need to print loss value, so disable per iteration output
)
val_stats_handler.attach(evaluator)
# for the array data format, assume the 3rd item of batch data is the meta_data
prediction_saver = ClassificationSaver(
output_dir="tempdir",
batch_transform=lambda batch: batch[2],
output_transform=lambda output: output[0].argmax(1),
)
prediction_saver.attach(evaluator)
# the model was trained by "densenet_training_array" example
CheckpointLoader(load_path="./runs_array/net_checkpoint_20.pt",
load_dict={
"net": net
}).attach(evaluator)
# create a validation data loader
val_loader = DataLoader(val_ds,
batch_size=2,
num_workers=4,
pin_memory=torch.cuda.is_available())
state = evaluator.run(val_loader)
print(state)
def main():
monai.config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
# IXI dataset as a demo, downloadable from https://brain-development.org/ixi-dataset/
images = [
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI314-IOP-0889-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI249-Guys-1072-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI609-HH-2600-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI173-HH-1590-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI020-Guys-0700-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI342-Guys-0909-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI134-Guys-0780-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI577-HH-2661-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI066-Guys-0731-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI130-HH-1528-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI607-Guys-1097-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI175-HH-1570-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI385-HH-2078-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI344-Guys-0905-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI409-Guys-0960-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI584-Guys-1129-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI253-HH-1694-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI092-HH-1436-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI574-IOP-1156-T1.nii.gz"
]),
os.sep.join([
"workspace", "data", "medical", "ixi", "IXI-T1",
"IXI585-Guys-1130-T1.nii.gz"
]),
]
# 2 binary labels for gender classification: man and woman
labels = np.array(
[0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0],
dtype=np.int64)
# define transforms
train_transforms = Compose([
ScaleIntensity(),
AddChannel(),
Resize((96, 96, 96)),
RandRotate90(),
ToTensor()
])
val_transforms = Compose(
[ScaleIntensity(),
AddChannel(),
Resize((96, 96, 96)),
ToTensor()])
# define image dataset, data loader
check_ds = ImageDataset(image_files=images,
labels=labels,
transform=train_transforms)
check_loader = DataLoader(check_ds,
batch_size=2,
num_workers=2,
pin_memory=torch.cuda.is_available())
im, label = monai.utils.misc.first(check_loader)
print(type(im), im.shape, label)
# create DenseNet121, CrossEntropyLoss and Adam optimizer
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
net = monai.networks.nets.densenet.densenet121(spatial_dims=3,
in_channels=1,
out_channels=2).to(device)
loss = torch.nn.CrossEntropyLoss()
lr = 1e-5
opt = torch.optim.Adam(net.parameters(), lr)
# Ignite trainer expects batch=(img, label) and returns output=loss at every iteration,
# user can add output_transform to return other values, like: y_pred, y, etc.
trainer = create_supervised_trainer(net, opt, loss, device, False)
# adding checkpoint handler to save models (network params and optimizer stats) during training
checkpoint_handler = ModelCheckpoint("./runs_array/",
"net",
n_saved=10,
require_empty=False)
trainer.add_event_handler(event_name=Events.EPOCH_COMPLETED,
handler=checkpoint_handler,
to_save={
"net": net,
"opt": opt
})
# StatsHandler prints loss at every iteration and print metrics at every epoch,
# we don't set metrics for trainer here, so just print loss, user can also customize print functions
# and can use output_transform to convert engine.state.output if it's not loss value
train_stats_handler = StatsHandler(name="trainer")
train_stats_handler.attach(trainer)
# TensorBoardStatsHandler plots loss at every iteration and plots metrics at every epoch, same as StatsHandler
train_tensorboard_stats_handler = TensorBoardStatsHandler()
train_tensorboard_stats_handler.attach(trainer)
# set parameters for validation
validation_every_n_epochs = 1
metric_name = "Accuracy"
# add evaluation metric to the evaluator engine
val_metrics = {metric_name: Accuracy()}
# Ignite evaluator expects batch=(img, label) and returns output=(y_pred, y) at every iteration,
# user can add output_transform to return other values
evaluator = create_supervised_evaluator(net, val_metrics, device, True)
# add stats event handler to print validation stats via evaluator
val_stats_handler = StatsHandler(
name="evaluator",
output_transform=lambda x:
None, # no need to print loss value, so disable per iteration output
global_epoch_transform=lambda x: trainer.state.epoch,
) # fetch global epoch number from trainer
val_stats_handler.attach(evaluator)
# add handler to record metrics to TensorBoard at every epoch
val_tensorboard_stats_handler = TensorBoardStatsHandler(
output_transform=lambda x:
None, # no need to plot loss value, so disable per iteration output
global_epoch_transform=lambda x: trainer.state.epoch,
) # fetch global epoch number from trainer
val_tensorboard_stats_handler.attach(evaluator)
# add early stopping handler to evaluator
early_stopper = EarlyStopping(
patience=4,
score_function=stopping_fn_from_metric(metric_name),
trainer=trainer)
evaluator.add_event_handler(event_name=Events.EPOCH_COMPLETED,
handler=early_stopper)
# create a validation data loader
val_ds = ImageDataset(image_files=images[-10:],
labels=labels[-10:],
transform=val_transforms)
val_loader = DataLoader(val_ds,
batch_size=2,
num_workers=2,
pin_memory=torch.cuda.is_available())
@trainer.on(Events.EPOCH_COMPLETED(every=validation_every_n_epochs))
def run_validation(engine):
evaluator.run(val_loader)
# create a training data loader
train_ds = ImageDataset(image_files=images[:10],
labels=labels[:10],
transform=train_transforms)
train_loader = DataLoader(train_ds,
batch_size=2,
shuffle=True,
num_workers=2,
pin_memory=torch.cuda.is_available())
train_epochs = 30
state = trainer.run(train_loader, train_epochs)
print(state)
def main(tempdir):
monai.config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
# create a temporary directory and 40 random image, mask pairs
print(f"generating synthetic data to {tempdir} (this may take a while)")
for i in range(40):
im, seg = create_test_image_3d(128, 128, 128, num_seg_classes=1)
n = nib.Nifti1Image(im, np.eye(4))
nib.save(n, os.path.join(tempdir, f"im{i:d}.nii.gz"))
n = nib.Nifti1Image(seg, np.eye(4))
nib.save(n, os.path.join(tempdir, f"seg{i:d}.nii.gz"))
images = sorted(glob(os.path.join(tempdir, "im*.nii.gz")))
segs = sorted(glob(os.path.join(tempdir, "seg*.nii.gz")))
# define transforms for image and segmentation
train_imtrans = Compose([
ScaleIntensity(),
AddChannel(),
RandSpatialCrop((96, 96, 96), random_size=False),
RandRotate90(prob=0.5, spatial_axes=(0, 2)),
ToTensor(),
])
train_segtrans = Compose([
AddChannel(),
RandSpatialCrop((96, 96, 96), random_size=False),
RandRotate90(prob=0.5, spatial_axes=(0, 2)),
ToTensor(),
])
val_imtrans = Compose([ScaleIntensity(), AddChannel(), ToTensor()])
val_segtrans = Compose([AddChannel(), ToTensor()])
# define image dataset, data loader
check_ds = ImageDataset(images,
segs,
transform=train_imtrans,
seg_transform=train_segtrans)
check_loader = DataLoader(check_ds,
batch_size=10,
num_workers=2,
pin_memory=torch.cuda.is_available())
im, seg = monai.utils.misc.first(check_loader)
print(im.shape, seg.shape)
# create a training data loader
train_ds = ImageDataset(images[:20],
segs[:20],
transform=train_imtrans,
seg_transform=train_segtrans)
train_loader = DataLoader(train_ds,
batch_size=4,
shuffle=True,
num_workers=8,
pin_memory=torch.cuda.is_available())
# create a validation data loader
val_ds = ImageDataset(images[-20:],
segs[-20:],
transform=val_imtrans,
seg_transform=val_segtrans)
val_loader = DataLoader(val_ds,
batch_size=1,
num_workers=4,
pin_memory=torch.cuda.is_available())
dice_metric = DiceMetric(include_background=True, reduction="mean")
post_trans = Compose(
[Activations(sigmoid=True),
AsDiscrete(threshold_values=True)])
# create UNet, DiceLoss and Adam optimizer
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = monai.networks.nets.UNet(
dimensions=3,
in_channels=1,
out_channels=1,
channels=(16, 32, 64, 128, 256),
strides=(2, 2, 2, 2),
num_res_units=2,
).to(device)
loss_function = monai.losses.DiceLoss(sigmoid=True)
optimizer = torch.optim.Adam(model.parameters(), 1e-3)
# start a typical PyTorch training
val_interval = 2
best_metric = -1
best_metric_epoch = -1
epoch_loss_values = list()
metric_values = list()
writer = SummaryWriter()
for epoch in range(5):
print("-" * 10)
print(f"epoch {epoch + 1}/{5}")
model.train()
epoch_loss = 0
step = 0
for batch_data in train_loader:
step += 1
inputs, labels = batch_data[0].to(device), batch_data[1].to(device)
optimizer.zero_grad()
outputs = model(inputs)
loss = loss_function(outputs, labels)
loss.backward()
optimizer.step()
epoch_loss += loss.item()
epoch_len = len(train_ds) // train_loader.batch_size
print(f"{step}/{epoch_len}, train_loss: {loss.item():.4f}")
writer.add_scalar("train_loss", loss.item(),
epoch_len * epoch + step)
epoch_loss /= step
epoch_loss_values.append(epoch_loss)
print(f"epoch {epoch + 1} average loss: {epoch_loss:.4f}")
if (epoch + 1) % val_interval == 0:
model.eval()
with torch.no_grad():
metric_sum = 0.0
metric_count = 0
val_images = None
val_labels = None
val_outputs = None
for val_data in val_loader:
val_images, val_labels = val_data[0].to(
device), val_data[1].to(device)
roi_size = (96, 96, 96)
sw_batch_size = 4
val_outputs = sliding_window_inference(
val_images, roi_size, sw_batch_size, model)
val_outputs = post_trans(val_outputs)
value, _ = dice_metric(y_pred=val_outputs, y=val_labels)
metric_count += len(value)
metric_sum += value.item() * len(value)
metric = metric_sum / metric_count
metric_values.append(metric)
if metric > best_metric:
best_metric = metric
best_metric_epoch = epoch + 1
torch.save(model.state_dict(),
"best_metric_model_segmentation3d_array.pth")
print("saved new best metric model")
print(
"current epoch: {} current mean dice: {:.4f} best mean dice: {:.4f} at epoch {}"
.format(epoch + 1, metric, best_metric, best_metric_epoch))
writer.add_scalar("val_mean_dice", metric, epoch + 1)
# plot the last model output as GIF image in TensorBoard with the corresponding image and label
plot_2d_or_3d_image(val_images,
epoch + 1,
writer,
index=0,
tag="image")
plot_2d_or_3d_image(val_labels,
epoch + 1,
writer,
index=0,
tag="label")
plot_2d_or_3d_image(val_outputs,
epoch + 1,
writer,
index=0,
tag="output")
print(
f"train completed, best_metric: {best_metric:.4f} at epoch: {best_metric_epoch}"
)
writer.close()
def main(tempdir):
monai.config.print_config()
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
# create a temporary directory and 40 random image, mask pairs
print(f"generating synthetic data to {tempdir} (this may take a while)")
for i in range(40):
im, seg = create_test_image_3d(128, 128, 128, num_seg_classes=1)
n = nib.Nifti1Image(im, np.eye(4))
nib.save(n, os.path.join(tempdir, f"im{i:d}.nii.gz"))
n = nib.Nifti1Image(seg, np.eye(4))
nib.save(n, os.path.join(tempdir, f"seg{i:d}.nii.gz"))
images = sorted(glob(os.path.join(tempdir, "im*.nii.gz")))
segs = sorted(glob(os.path.join(tempdir, "seg*.nii.gz")))
# define transforms for image and segmentation
train_imtrans = Compose(
[
ScaleIntensity(),
AddChannel(),
RandSpatialCrop((96, 96, 96), random_size=False),
ToTensor(),
]
)
train_segtrans = Compose(
[AddChannel(), RandSpatialCrop((96, 96, 96), random_size=False), ToTensor()]
)
val_imtrans = Compose(
[ScaleIntensity(), AddChannel(), Resize((96, 96, 96)), ToTensor()]
)
val_segtrans = Compose([AddChannel(), Resize((96, 96, 96)), ToTensor()])
# define image dataset, data loader
check_ds = ImageDataset(
images, segs, transform=train_imtrans, seg_transform=train_segtrans
)
check_loader = DataLoader(
check_ds, batch_size=10, num_workers=2, pin_memory=torch.cuda.is_available()
)
im, seg = monai.utils.misc.first(check_loader)
print(im.shape, seg.shape)
# create a training data loader
train_ds = ImageDataset(
images[:20], segs[:20], transform=train_imtrans, seg_transform=train_segtrans
)
train_loader = DataLoader(
train_ds,
batch_size=5,
shuffle=True,
num_workers=8,
pin_memory=torch.cuda.is_available(),
)
# create a validation data loader
val_ds = ImageDataset(
images[-20:], segs[-20:], transform=val_imtrans, seg_transform=val_segtrans
)
val_loader = DataLoader(
val_ds, batch_size=5, num_workers=8, pin_memory=torch.cuda.is_available()
)
# create UNet, DiceLoss and Adam optimizer
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
net = monai.networks.nets.UNet(
dimensions=3,
in_channels=1,
out_channels=1,
channels=(16, 32, 64, 128, 256),
strides=(2, 2, 2, 2),
num_res_units=2,
).to(device)
loss = monai.losses.DiceLoss(sigmoid=True)
lr = 1e-3
opt = torch.optim.Adam(net.parameters(), lr)
# Ignite trainer expects batch=(img, seg) and returns output=loss at every iteration,
# user can add output_transform to return other values, like: y_pred, y, etc.
trainer = create_supervised_trainer(net, opt, loss, device, False)
# adding checkpoint handler to save models (network params and optimizer stats) during training
checkpoint_handler = ModelCheckpoint(
"./runs_array/", "net", n_saved=10, require_empty=False
)
trainer.add_event_handler(
event_name=Events.EPOCH_COMPLETED,
handler=checkpoint_handler,
to_save={"net": net, "opt": opt},
)
# StatsHandler prints loss at every iteration and print metrics at every epoch,
# we don't set metrics for trainer here, so just print loss, user can also customize print functions
# and can use output_transform to convert engine.state.output if it's not a loss value
train_stats_handler = StatsHandler(name="trainer")
train_stats_handler.attach(trainer)
# TensorBoardStatsHandler plots loss at every iteration and plots metrics at every epoch, same as StatsHandler
train_tensorboard_stats_handler = TensorBoardStatsHandler()
train_tensorboard_stats_handler.attach(trainer)
validation_every_n_epochs = 1
# Set parameters for validation
metric_name = "Mean_Dice"
# add evaluation metric to the evaluator engine
val_metrics = {metric_name: MeanDice()}
post_pred = Compose([Activations(sigmoid=True), AsDiscrete(threshold_values=True)])
post_label = AsDiscrete(threshold_values=True)
# Ignite evaluator expects batch=(img, seg) and returns output=(y_pred, y) at every iteration,
# user can add output_transform to return other values
evaluator = create_supervised_evaluator(
net,
val_metrics,
device,
True,
output_transform=lambda x, y, y_pred: (post_pred(y_pred), post_label(y)),
)
@trainer.on(Events.EPOCH_COMPLETED(every=validation_every_n_epochs))
def run_validation(engine):
evaluator.run(val_loader)
# add early stopping handler to evaluator
early_stopper = EarlyStopping(
patience=4, score_function=stopping_fn_from_metric(metric_name), trainer=trainer
)
evaluator.add_event_handler(
event_name=Events.EPOCH_COMPLETED, handler=early_stopper
)
# add stats event handler to print validation stats via evaluator
val_stats_handler = StatsHandler(
name="evaluator",
output_transform=lambda x: None, # no need to print loss value, so disable per iteration output
global_epoch_transform=lambda x: trainer.state.epoch,
) # fetch global epoch number from trainer
val_stats_handler.attach(evaluator)
# add handler to record metrics to TensorBoard at every validation epoch
val_tensorboard_stats_handler = TensorBoardStatsHandler(
output_transform=lambda x: None, # no need to plot loss value, so disable per iteration output
global_epoch_transform=lambda x: trainer.state.epoch,
) # fetch global epoch number from trainer
val_tensorboard_stats_handler.attach(evaluator)
# add handler to draw the first image and the corresponding label and model output in the last batch
# here we draw the 3D output as GIF format along Depth axis, at every validation epoch
val_tensorboard_image_handler = TensorBoardImageHandler(
batch_transform=lambda batch: (batch[0], batch[1]),
output_transform=lambda output: output[0],
global_iter_transform=lambda x: trainer.state.epoch,
)
evaluator.add_event_handler(
event_name=Events.EPOCH_COMPLETED, handler=val_tensorboard_image_handler
)
train_epochs = 30
state = trainer.run(train_loader, train_epochs)
print(state)