def validate(args):
# load trained param file
_ = nn.load_parameters(args.model_load_path)
# get data iterator
vdata = data_iterator_segmentation(args.val_samples, args.batch_size,
args.val_dir, args.val_label_dir)
# get deeplabv3plus model
v_model = train.get_model(args, test=True)
v_model.pred.persistent = True # Not clearing buffer of pred in forward
v_pred2 = v_model.pred.unlinked()
# Create monitor
monitor = M.Monitor(args.monitor_path)
monitor_miou = M.MonitorSeries("mean IOU", monitor, interval=1)
l = 0.0
e = 0.0
vmiou = 0.
# Evaluation loop
for j in range(args.val_samples // args.batch_size):
images, labels, masks = vdata.next()
v_model.image.d = images
v_model.label.d = labels
v_model.mask.d = masks
v_model.pred.forward(clear_buffer=True)
miou = train.compute_miou(args.num_class, labels,
np.argmax(v_model.pred.d, axis=1), masks)
vmiou += miou
print(j, miou)
monitor_miou.add(0, vmiou / (args.val_samples / args.batch_size))
return vmiou / args.val_samples
def train():
"""
Main script.
"""
args = get_args()
_ = nn.load_parameters(args.pretrained_model_path)
if args.fine_tune:
nnabla.parameter.pop_parameter('decoder/logits/affine/conv/W')
nnabla.parameter.pop_parameter('decoder/logits/affine/conv/b')
n_train_samples = args.train_samples
n_val_samples = args.val_samples
distributed = args.distributed
compute_acc = args.compute_acc
if distributed:
# Communicator and Context
from nnabla.ext_utils import get_extension_context
extension_module = "cudnn"
ctx = get_extension_context(
extension_module, type_config=args.type_config)
comm = C.MultiProcessDataParalellCommunicator(ctx)
comm.init()
n_devices = comm.size
mpi_rank = comm.rank
device_id = mpi_rank
ctx.device_id = str(device_id)
nn.set_default_context(ctx)
else:
# Get context.
from nnabla.ext_utils import get_extension_context
extension_module = args.context
if args.context is None:
extension_module = 'cpu'
logger.info("Running in %s" % extension_module)
ctx = get_extension_context(
extension_module, device_id=args.device_id, type_config=args.type_config)
nn.set_default_context(ctx)
n_devices = 1
device_id = 0
# training data
data = data_iterator_segmentation(
args.train_samples, args.batch_size, args.train_dir, args.train_label_dir, target_width=args.image_width, target_height=args.image_height)
# validation data
vdata = data_iterator_segmentation(args.val_samples, args.batch_size, args.val_dir,
args.val_label_dir, target_width=args.image_width, target_height=args.image_height)
if distributed:
data = data.slice(
rng=None, num_of_slices=n_devices, slice_pos=device_id)
vdata = vdata.slice(
rng=None, num_of_slices=n_devices, slice_pos=device_id)
num_classes = args.num_class
# Workaround to start with the same initialized weights for all workers.
np.random.seed(313)
t_model = get_model(
args, test=False)
t_model.pred.persistent = True # Not clearing buffer of pred in backward
t_pred2 = t_model.pred.unlinked()
t_e = F.sum(F.top_n_error(t_pred2, t_model.label, axis=1)
* t_model.mask) / F.sum(t_model.mask)
v_model = get_model(
args, test=True)
v_model.pred.persistent = True # Not clearing buffer of pred in forward
v_pred2 = v_model.pred.unlinked()
v_e = F.sum(F.top_n_error(v_pred2, v_model.label, axis=1)
* v_model.mask) / F.sum(t_model.mask)
# Create Solver
solver = S.Momentum(args.learning_rate, 0.9)
solver.set_parameters(nn.get_parameters())
# Load checkpoint
start_point = 0
if args.checkpoint is not None:
# load weights and solver state info from specified checkpoint file.
start_point = load_checkpoint(args.checkpoint, solver)
# Setting warmup.
base_lr = args.learning_rate / n_devices
warmup_iter = int(1. * n_train_samples /
args.batch_size / args.accum_grad / n_devices) * args.warmup_epoch
warmup_slope = base_lr * (n_devices - 1) / warmup_iter
solver.set_learning_rate(base_lr)
# Create monitor
import nnabla.monitor as M
monitor = M.Monitor(args.monitor_path)
monitor_loss = M.MonitorSeries("Training loss", monitor, interval=10)
monitor_err = M.MonitorSeries("Training error", monitor, interval=10)
monitor_vloss = M.MonitorSeries("Validation loss", monitor, interval=1)
monitor_verr = M.MonitorSeries("Validation error", monitor, interval=1)
monitor_time = M.MonitorTimeElapsed("Training time", monitor, interval=10)
monitor_miou = M.MonitorSeries("mean IOU", monitor, interval=10)
monitor_vtime = M.MonitorTimeElapsed(
"Validation time", monitor, interval=1)
# save_nnp
contents = save_nnp({'x': v_model.image}, {
'y': v_model.pred}, args.batch_size)
save.save(os.path.join(args.model_save_path,
'Deeplabv3plus_result_epoch0.nnp'), contents, variable_batch_size=False)
# Training loop
for i in range(start_point, int(args.max_iter / n_devices)):
# Save parameters
if i % (args.model_save_interval // n_devices) == 0 and device_id == 0:
save_checkpoint(args.model_save_path, i, solver)
# Validation
if i % (args.val_interval // n_devices) == 0 and i != 0:
vmiou_local = 0.
val_iter_local = n_val_samples // args.batch_size
vl_local = nn.NdArray()
vl_local.zero()
ve_local = nn.NdArray()
ve_local.zero()
for j in range(val_iter_local):
images, labels, masks = vdata.next()
v_model.image.d = images
v_model.label.d = labels
v_model.mask.d = masks
v_model.image.data.cast(np.float32, ctx)
v_model.label.data.cast(np.int32, ctx)
v_model.loss.forward(clear_buffer=True)
v_e.forward(clear_buffer=True)
vl_local += v_model.loss.data
ve_local += v_e.data
# Mean IOU computation
if compute_acc:
vmiou_local += compute_miou(num_classes, labels,
np.argmax(v_model.pred.d, axis=1), masks)
vl_local /= val_iter_local
ve_local /= val_iter_local
if compute_acc:
vmiou_local /= val_iter_local
vmiou_ndarray = nn.NdArray.from_numpy_array(
np.array(vmiou_local))
if distributed:
comm.all_reduce(vl_local, division=True, inplace=True)
comm.all_reduce(ve_local, division=True, inplace=True)
if compute_acc:
comm.all_reduce(vmiou_ndarray, division=True, inplace=True)
if device_id == 0:
monitor_vloss.add(i * n_devices, vl_local.data.copy())
monitor_verr.add(i * n_devices, ve_local.data.copy())
if compute_acc:
monitor_miou.add(i * n_devices, vmiou_local)
monitor_vtime.add(i * n_devices)
# Training
l = 0.0
e = 0.0
solver.zero_grad()
e_acc = nn.NdArray(t_e.shape)
e_acc.zero()
l_acc = nn.NdArray(t_model.loss.shape)
l_acc.zero()
# Gradient accumulation loop
for j in range(args.accum_grad):
images, labels, masks = data.next()
t_model.image.d = images
t_model.label.d = labels
t_model.mask.d = masks
t_model.image.data.cast(np.float32, ctx)
t_model.label.data.cast(np.int32, ctx)
t_model.loss.forward(clear_no_need_grad=True)
t_model.loss.backward(clear_buffer=True) # Accumulating gradients
t_e.forward(clear_buffer=True)
e_acc += t_e.data
l_acc += t_model.loss.data
# AllReduce
if distributed:
params = [x.grad for x in nn.get_parameters().values()]
comm.all_reduce(params, division=False, inplace=False)
comm.all_reduce(l_acc, division=True, inplace=True)
comm.all_reduce(e_acc, division=True, inplace=True)
solver.scale_grad(1./args.accum_grad)
solver.weight_decay(args.weight_decay)
solver.update()
# Linear Warmup
if i <= warmup_iter:
lr = base_lr + warmup_slope * i
solver.set_learning_rate(lr)
if distributed:
# Synchronize by averaging the weights over devices using allreduce
if (i+1) % args.sync_weight_every_itr == 0:
weights = [x.data for x in nn.get_parameters().values()]
comm.all_reduce(weights, division=True, inplace=True)
if device_id == 0:
monitor_loss.add(
i * n_devices, (l_acc / args.accum_grad).data.copy())
monitor_err.add(
i * n_devices, (e_acc / args.accum_grad).data.copy())
monitor_time.add(i * n_devices)
# Learning rate decay at scheduled iter --> changed to poly learning rate decay policy
# if i in args.learning_rate_decay_at:
solver.set_learning_rate(base_lr * ((1 - i / args.max_iter)**0.1))
if device_id == 0:
nn.save_parameters(os.path.join(args.model_save_path,
'param_%06d.h5' % args.max_iter))
contents = save_nnp({'x': v_model.image}, {
'y': v_model.pred}, args.batch_size)
save.save(os.path.join(args.model_save_path,
'Deeplabv3plus_result.nnp'), contents, variable_batch_size=False)