def test_resnet_res_layer():
# Test ResLayer of 3 Bottleneck w\o downsample
layer = ResLayer(Bottleneck, 64, 16, 3)
assert len(layer) == 3
assert layer[0].conv1.in_channels == 64
assert layer[0].conv1.out_channels == 16
for i in range(1, len(layer)):
assert layer[i].conv1.in_channels == 64
assert layer[i].conv1.out_channels == 16
for i in range(len(layer)):
assert layer[i].downsample is None
x = torch.randn(1, 64, 56, 56)
x_out = layer(x)
assert x_out.shape == torch.Size([1, 64, 56, 56])
# Test ResLayer of 3 Bottleneck with downsample
layer = ResLayer(Bottleneck, 64, 64, 3)
assert layer[0].downsample[0].out_channels == 256
for i in range(1, len(layer)):
assert layer[i].downsample is None
x = torch.randn(1, 64, 56, 56)
x_out = layer(x)
assert x_out.shape == torch.Size([1, 256, 56, 56])
# Test ResLayer of 3 Bottleneck with stride=2
layer = ResLayer(Bottleneck, 64, 64, 3, stride=2)
assert layer[0].downsample[0].out_channels == 256
assert layer[0].downsample[0].stride == (2, 2)
for i in range(1, len(layer)):
assert layer[i].downsample is None
x = torch.randn(1, 64, 56, 56)
x_out = layer(x)
assert x_out.shape == torch.Size([1, 256, 28, 28])
# Test ResLayer of 3 Bottleneck with stride=2 and average downsample
layer = ResLayer(Bottleneck, 64, 64, 3, stride=2, avg_down=True)
assert isinstance(layer[0].downsample[0], AvgPool2d)
assert layer[0].downsample[1].out_channels == 256
assert layer[0].downsample[1].stride == (1, 1)
for i in range(1, len(layer)):
assert layer[i].downsample is None
x = torch.randn(1, 64, 56, 56)
x_out = layer(x)
assert x_out.shape == torch.Size([1, 256, 28, 28])
# Test ResLayer of 3 BasicBlock with stride=2 and downsample_first=False
layer = ResLayer(BasicBlock, 64, 64, 3, stride=2, downsample_first=False)
assert layer[2].downsample[0].out_channels == 64
assert layer[2].downsample[0].stride == (2, 2)
for i in range(len(layer) - 1):
assert layer[i].downsample is None
x = torch.randn(1, 64, 56, 56)
x_out = layer(x)
assert x_out.shape == torch.Size([1, 64, 28, 28])
def __init__(self,
num_convs=4,
in_channels=256,
conv_out_channels=256,
num_classes=80,
loss_weight=1.0,
conv_cfg=None,
norm_cfg=None,
conv_to_res=False,
init_cfg=dict(
type='Normal', std=0.01, override=dict(name='fc'))):
super(GlobalContextHead, self).__init__(init_cfg)
self.num_convs = num_convs
self.in_channels = in_channels
self.conv_out_channels = conv_out_channels
self.num_classes = num_classes
self.loss_weight = loss_weight
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
if self.conv_to_res:
num_res_blocks = num_convs // 2
self.convs = ResLayer(
SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.num_convs = num_res_blocks
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = self.in_channels if i == 0 else conv_out_channels
self.convs.append(
ConvModule(
in_channels,
conv_out_channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
self.pool = nn.AdaptiveAvgPool2d(1)
self.fc = nn.Linear(conv_out_channels, num_classes)
self.criterion = nn.BCEWithLogitsLoss()
def __init__(self, conv_to_res=True, **kwargs):
super(SCNetSemanticHead, self).__init__(**kwargs)
self.conv_to_res = conv_to_res
if self.conv_to_res:
num_res_blocks = self.num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
self.in_channels,
self.conv_out_channels,
num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.num_convs = num_res_blocks
def __init__(self, conv_to_res=True, **kwargs):
super(SCNetMaskHead, self).__init__(**kwargs)
self.conv_to_res = conv_to_res
if conv_to_res:
assert self.conv_kernel_size == 3
self.num_res_blocks = self.num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
self.in_channels,
self.conv_out_channels,
self.num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
class GlobalContextHead(nn.Module):
"""Global context head used in SCNet https://arxiv.org/abs/2012.10150.
Args:
num_convs (int, optional): number of convolutional layer in GlbCtxHead.
Default: 4.
in_channels (int, optional): number of input channels. Default: 256.
conv_out_channels (int, optional): number of output channels before
classification layer. Default: 256.
loss_weight (float, optional): global context loss weight. Default: 1.
conv_cfg (dict, optional): config to init conv layer. Default: None.
norm_cfg (dict, optional): config to init norm layer. Default: None.
conv_to_res (bool, optional): if True, 2 convs will be grouped into
1 `SimplifiedBasicBlock` using a skip connection. Default: False.
"""
def __init__(self,
num_convs=4,
in_channels=256,
conv_out_channels=256,
num_classes=81,
loss_weight=1.0,
conv_cfg=None,
norm_cfg=None,
conv_to_res=False):
super(GlobalContextHead, self).__init__()
self.num_convs = num_convs
self.in_channels = in_channels
self.conv_out_channels = conv_out_channels
self.num_classes = num_classes
self.loss_weight = loss_weight
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
if self.conv_to_res:
num_res_blocks = num_convs // 2
self.convs = ResLayer(
SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.num_convs = num_res_blocks
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = self.in_channels if i == 0 else conv_out_channels
self.convs.append(
ConvModule(
in_channels,
conv_out_channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
self.pool = nn.AdaptiveAvgPool2d(1)
self.fc = nn.Linear(conv_out_channels, num_classes)
self.criterion = nn.BCEWithLogitsLoss()
def init_weights(self):
"""Init weights for the head."""
nn.init.normal_(self.fc.weight, 0, 0.01)
nn.init.constant_(self.fc.bias, 0)
@auto_fp16()
def forward(self, feats):
"""Forward function."""
x = feats[-1]
for i in range(self.num_convs):
x = self.convs[i](x)
x = self.pool(x)
# multi-class prediction
mc_pred = x.reshape(x.size(0), -1)
mc_pred = self.fc(mc_pred)
return mc_pred, x
@force_fp32(apply_to=('pred', ))
def loss(self, pred, labels):
"""Loss function."""
labels = [lbl.unique() for lbl in labels]
targets = pred.new_zeros(pred.size())
for i, label in enumerate(labels):
targets[i, label] = 1.0
loss = self.loss_weight * self.criterion(pred, targets)
return loss
def __init__(self,
num_convs=4,
roi_feat_size=14,
in_channels=256,
conv_kernel_size=3,
conv_out_channels=256,
num_classes=80,
class_agnostic=False,
upsample_cfg=dict(type='deconv', scale_factor=2),
conv_cfg=None,
norm_cfg=None,
conv_to_res=False,
loss_mask=dict(type='CrossEntropyLoss',
use_mask=True,
loss_weight=1.0)):
super(FCNMaskHead, self).__init__()
self.upsample_cfg = upsample_cfg.copy()
if self.upsample_cfg['type'] not in [
None, 'deconv', 'nearest', 'bilinear', 'carafe'
]:
raise ValueError(
f'Invalid upsample method {self.upsample_cfg["type"]}, '
'accepted methods are "deconv", "nearest", "bilinear", '
'"carafe"')
self.num_convs = num_convs
# WARN: roi_feat_size is reserved and not used
self.roi_feat_size = _pair(roi_feat_size)
self.in_channels = in_channels
self.conv_kernel_size = conv_kernel_size
self.conv_out_channels = conv_out_channels
self.upsample_method = self.upsample_cfg.get('type')
self.scale_factor = self.upsample_cfg.pop('scale_factor', None)
self.num_classes = num_classes
self.class_agnostic = class_agnostic
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
self.loss_mask = build_loss(loss_mask)
if conv_to_res:
assert conv_kernel_size == 3
self.num_res_blocks = num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
self.num_res_blocks,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg)
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = (self.in_channels
if i == 0 else self.conv_out_channels)
padding = (self.conv_kernel_size - 1) // 2
self.convs.append(
ConvModule(in_channels,
self.conv_out_channels,
self.conv_kernel_size,
padding=padding,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg))
upsample_in_channels = (self.conv_out_channels
if self.num_convs > 0 else in_channels)
upsample_cfg_ = self.upsample_cfg.copy()
if self.upsample_method is None:
self.upsample = None
elif self.upsample_method == 'deconv':
upsample_cfg_.update(in_channels=upsample_in_channels,
out_channels=self.conv_out_channels,
kernel_size=self.scale_factor,
stride=self.scale_factor)
self.upsample = build_upsample_layer(upsample_cfg_)
elif self.upsample_method == 'carafe':
upsample_cfg_.update(channels=upsample_in_channels,
scale_factor=self.scale_factor)
self.upsample = build_upsample_layer(upsample_cfg_)
else:
# suppress warnings
align_corners = (None
if self.upsample_method == 'nearest' else False)
upsample_cfg_.update(scale_factor=self.scale_factor,
mode=self.upsample_method,
align_corners=align_corners)
self.upsample = build_upsample_layer(upsample_cfg_)
out_channels = 1 if self.class_agnostic else self.num_classes
logits_in_channel = (self.conv_out_channels if self.upsample_method
== 'deconv' else upsample_in_channels)
self.conv_logits = Conv2d(logits_in_channel, out_channels, 1)
self.relu = nn.ReLU(inplace=True)
self.debug_imgs = None
class FCNMaskHead(nn.Module):
def __init__(self,
num_convs=4,
roi_feat_size=14,
in_channels=256,
conv_kernel_size=3,
conv_out_channels=256,
num_classes=80,
class_agnostic=False,
upsample_cfg=dict(type='deconv', scale_factor=2),
conv_cfg=None,
norm_cfg=None,
conv_to_res=False,
loss_mask=dict(type='CrossEntropyLoss',
use_mask=True,
loss_weight=1.0)):
super(FCNMaskHead, self).__init__()
self.upsample_cfg = upsample_cfg.copy()
if self.upsample_cfg['type'] not in [
None, 'deconv', 'nearest', 'bilinear', 'carafe'
]:
raise ValueError(
f'Invalid upsample method {self.upsample_cfg["type"]}, '
'accepted methods are "deconv", "nearest", "bilinear", '
'"carafe"')
self.num_convs = num_convs
# WARN: roi_feat_size is reserved and not used
self.roi_feat_size = _pair(roi_feat_size)
self.in_channels = in_channels
self.conv_kernel_size = conv_kernel_size
self.conv_out_channels = conv_out_channels
self.upsample_method = self.upsample_cfg.get('type')
self.scale_factor = self.upsample_cfg.pop('scale_factor', None)
self.num_classes = num_classes
self.class_agnostic = class_agnostic
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
self.loss_mask = build_loss(loss_mask)
if conv_to_res:
assert conv_kernel_size == 3
self.num_res_blocks = num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
self.num_res_blocks,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg)
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = (self.in_channels
if i == 0 else self.conv_out_channels)
padding = (self.conv_kernel_size - 1) // 2
self.convs.append(
ConvModule(in_channels,
self.conv_out_channels,
self.conv_kernel_size,
padding=padding,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg))
upsample_in_channels = (self.conv_out_channels
if self.num_convs > 0 else in_channels)
upsample_cfg_ = self.upsample_cfg.copy()
if self.upsample_method is None:
self.upsample = None
elif self.upsample_method == 'deconv':
upsample_cfg_.update(in_channels=upsample_in_channels,
out_channels=self.conv_out_channels,
kernel_size=self.scale_factor,
stride=self.scale_factor)
self.upsample = build_upsample_layer(upsample_cfg_)
elif self.upsample_method == 'carafe':
upsample_cfg_.update(channels=upsample_in_channels,
scale_factor=self.scale_factor)
self.upsample = build_upsample_layer(upsample_cfg_)
else:
# suppress warnings
align_corners = (None
if self.upsample_method == 'nearest' else False)
upsample_cfg_.update(scale_factor=self.scale_factor,
mode=self.upsample_method,
align_corners=align_corners)
self.upsample = build_upsample_layer(upsample_cfg_)
out_channels = 1 if self.class_agnostic else self.num_classes
logits_in_channel = (self.conv_out_channels if self.upsample_method
== 'deconv' else upsample_in_channels)
self.conv_logits = Conv2d(logits_in_channel, out_channels, 1)
self.relu = nn.ReLU(inplace=True)
self.debug_imgs = None
def init_weights(self):
for m in [self.upsample, self.conv_logits]:
if m is None:
continue
elif isinstance(m, CARAFEPack):
m.init_weights()
else:
nn.init.kaiming_normal_(m.weight,
mode='fan_out',
nonlinearity='relu')
nn.init.constant_(m.bias, 0)
@auto_fp16()
def forward(self, x):
for conv in self.convs:
x = conv(x)
if self.upsample is not None:
x = self.upsample(x)
if self.upsample_method == 'deconv':
x = self.relu(x)
mask_pred = self.conv_logits(x)
return mask_pred
def get_targets(self, sampling_results, gt_masks, rcnn_train_cfg):
pos_proposals = [res.pos_bboxes for res in sampling_results]
pos_assigned_gt_inds = [
res.pos_assigned_gt_inds for res in sampling_results
]
mask_targets = mask_target(pos_proposals, pos_assigned_gt_inds,
gt_masks, rcnn_train_cfg)
return mask_targets
@force_fp32(apply_to=('mask_pred', ))
def loss(self, mask_pred, mask_targets, labels):
loss = dict()
if mask_pred.size(0) == 0:
loss_mask = mask_pred.sum()
else:
if self.class_agnostic:
loss_mask = self.loss_mask(mask_pred, mask_targets,
torch.zeros_like(labels))
else:
loss_mask = self.loss_mask(mask_pred, mask_targets, labels)
loss['loss_mask'] = loss_mask
return loss
def get_seg_masks(self, mask_pred, det_bboxes, det_labels, rcnn_test_cfg,
ori_shape, scale_factor, rescale):
"""Get segmentation masks from mask_pred and bboxes.
Args:
mask_pred (Tensor or ndarray): shape (n, #class, h, w).
For single-scale testing, mask_pred is the direct output of
model, whose type is Tensor, while for multi-scale testing,
it will be converted to numpy array outside of this method.
det_bboxes (Tensor): shape (n, 4/5)
det_labels (Tensor): shape (n, )
img_shape (Tensor): shape (3, )
rcnn_test_cfg (dict): rcnn testing config
ori_shape: original image size
Returns:
list[list]: encoded masks
"""
if isinstance(mask_pred, torch.Tensor):
mask_pred = mask_pred.sigmoid()
else:
mask_pred = det_bboxes.new_tensor(mask_pred)
device = mask_pred.device
cls_segms = [[] for _ in range(self.num_classes)
] # BG is not included in num_classes
bboxes = det_bboxes[:, :4]
labels = det_labels
if rescale:
img_h, img_w = ori_shape[:2]
else:
if isinstance(scale_factor, float):
img_h = np.round(ori_shape[0] * scale_factor).astype(np.int32)
img_w = np.round(ori_shape[1] * scale_factor).astype(np.int32)
else:
w_scale, h_scale = scale_factor[0], scale_factor[1]
img_h = np.round(ori_shape[0] * h_scale.item()).astype(
np.int32)
img_w = np.round(ori_shape[1] * w_scale.item()).astype(
np.int32)
scale_factor = 1.0
if not isinstance(scale_factor, (float, torch.Tensor)):
scale_factor = bboxes.new_tensor(scale_factor)
bboxes = bboxes / scale_factor
if torch.onnx.is_in_onnx_export():
# TODO: Remove after F.grid_sample is supported.
from torchvision.models.detection.roi_heads \
import paste_masks_in_image
masks = paste_masks_in_image(mask_pred, bboxes, ori_shape[:2])
thr = rcnn_test_cfg.get('mask_thr_binary', 0)
if thr > 0:
masks = masks >= thr
return masks
N = len(mask_pred)
# The actual implementation split the input into chunks,
# and paste them chunk by chunk.
if device.type == 'cpu':
# CPU is most efficient when they are pasted one by one with
# skip_empty=True, so that it performs minimal number of
# operations.
num_chunks = N
else:
# GPU benefits from parallelism for larger chunks,
# but may have memory issue
num_chunks = int(
np.ceil(N * img_h * img_w * BYTES_PER_FLOAT / GPU_MEM_LIMIT))
assert (num_chunks <=
N), 'Default GPU_MEM_LIMIT is too small; try increasing it'
chunks = torch.chunk(torch.arange(N, device=device), num_chunks)
threshold = rcnn_test_cfg.mask_thr_binary
im_mask = torch.zeros(
N,
img_h,
img_w,
device=device,
dtype=torch.bool if threshold >= 0 else torch.uint8)
if not self.class_agnostic:
mask_pred = mask_pred[range(N), labels][:, None]
for inds in chunks:
masks_chunk, spatial_inds = _do_paste_mask(
mask_pred[inds],
bboxes[inds],
img_h,
img_w,
skip_empty=device.type == 'cpu')
if threshold >= 0:
masks_chunk = (masks_chunk >= threshold).to(dtype=torch.bool)
else:
# for visualization and debugging
masks_chunk = (masks_chunk * 255).to(dtype=torch.uint8)
im_mask[(inds, ) + spatial_inds] = masks_chunk
for i in range(N):
cls_segms[labels[i]].append(im_mask[i].detach().cpu().numpy())
return cls_segms
def make_res_layer(self, **kwargs):
"""Pack all blocks in a stage into a ``ResLayer``."""
return ResLayer(**kwargs)
def __init__(self,
num_ins,
fusion_level,
num_convs=4,
in_channels=256,
conv_out_channels=256,
num_classes=183,
ignore_label=255,
loss_weight=0.2,
conv_cfg=None,
norm_cfg=None,
conv_to_res=False):
super(FusedSemanticHead, self).__init__()
self.num_ins = num_ins
self.fusion_level = fusion_level
self.num_convs = num_convs
self.in_channels = in_channels
self.conv_out_channels = conv_out_channels
self.num_classes = num_classes
self.ignore_label = ignore_label
self.loss_weight = loss_weight
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
self.lateral_convs = nn.ModuleList()
for i in range(self.num_ins):
self.lateral_convs.append(
ConvModule(self.in_channels,
self.in_channels,
1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
inplace=False))
if self.conv_to_res:
num_res_blocks = num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.num_convs = num_res_blocks
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = self.in_channels if i == 0 else conv_out_channels
self.convs.append(
ConvModule(in_channels,
conv_out_channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
self.conv_embedding = ConvModule(conv_out_channels,
conv_out_channels,
1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.conv_logits = nn.Conv2d(conv_out_channels, self.num_classes, 1)
self.criterion = nn.CrossEntropyLoss(ignore_index=ignore_label)
class FusedSemanticHead(nn.Module):
r"""Multi-level fused semantic segmentation head.
.. code-block:: none
in_1 -> 1x1 conv ---
|
in_2 -> 1x1 conv -- |
||
in_3 -> 1x1 conv - ||
||| /-> 1x1 conv (mask prediction)
in_4 -> 1x1 conv -----> 3x3 convs (*4)
| \-> 1x1 conv (feature)
in_5 -> 1x1 conv ---
""" # noqa: W605
def __init__(self,
num_ins,
fusion_level,
num_convs=4,
in_channels=256,
conv_out_channels=256,
num_classes=183,
ignore_label=255,
loss_weight=0.2,
conv_cfg=None,
norm_cfg=None,
conv_to_res=False):
super(FusedSemanticHead, self).__init__()
self.num_ins = num_ins
self.fusion_level = fusion_level
self.num_convs = num_convs
self.in_channels = in_channels
self.conv_out_channels = conv_out_channels
self.num_classes = num_classes
self.ignore_label = ignore_label
self.loss_weight = loss_weight
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
self.lateral_convs = nn.ModuleList()
for i in range(self.num_ins):
self.lateral_convs.append(
ConvModule(self.in_channels,
self.in_channels,
1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
inplace=False))
if self.conv_to_res:
num_res_blocks = num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.num_convs = num_res_blocks
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = self.in_channels if i == 0 else conv_out_channels
self.convs.append(
ConvModule(in_channels,
conv_out_channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
self.conv_embedding = ConvModule(conv_out_channels,
conv_out_channels,
1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.conv_logits = nn.Conv2d(conv_out_channels, self.num_classes, 1)
self.criterion = nn.CrossEntropyLoss(ignore_index=ignore_label)
def init_weights(self):
kaiming_init(self.conv_logits)
@auto_fp16()
def forward(self, feats):
x = self.lateral_convs[self.fusion_level](feats[self.fusion_level])
fused_size = tuple(x.shape[-2:])
for i, feat in enumerate(feats):
if i != self.fusion_level:
feat = F.interpolate(feat,
size=fused_size,
mode='bilinear',
align_corners=True)
x += self.lateral_convs[i](feat)
for i in range(self.num_convs):
x = self.convs[i](x)
mask_pred = self.conv_logits(x)
x = self.conv_embedding(x)
return mask_pred, x
@force_fp32(apply_to=('mask_pred', ))
def loss(self, mask_pred, labels):
labels = labels.squeeze(1).long()
loss_semantic_seg = self.criterion(mask_pred, labels)
loss_semantic_seg *= self.loss_weight
return loss_semantic_seg
class GlobalContextHead(nn.Module):
"""Global context head."""
def __init__(self,
num_ins,
num_convs=4,
in_channels=256,
conv_out_channels=256,
num_classes=81,
loss_weight=1.0,
conv_cfg=None,
norm_cfg=None,
conv_to_res=False):
super(GlobalContextHead, self).__init__()
self.num_ins = num_ins
self.num_convs = num_convs
self.in_channels = in_channels
self.conv_out_channels = conv_out_channels
self.num_classes = num_classes
self.loss_weight = loss_weight
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.conv_to_res = conv_to_res
self.fp16_enabled = False
if self.conv_to_res:
num_res_blocks = num_convs // 2
self.convs = ResLayer(SimplifiedBasicBlock,
in_channels,
self.conv_out_channels,
num_res_blocks,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg)
self.num_convs = num_res_blocks
else:
self.convs = nn.ModuleList()
for i in range(self.num_convs):
in_channels = self.in_channels if i == 0 else conv_out_channels
self.convs.append(
ConvModule(in_channels,
conv_out_channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg))
self.pool = nn.AdaptiveAvgPool2d(1)
self.fc = nn.Linear(conv_out_channels, num_classes)
self.criterion = nn.BCEWithLogitsLoss()
def init_weights(self):
nn.init.normal_(self.fc.weight, 0, 0.01)
nn.init.constant_(self.fc.bias, 0)
@auto_fp16()
def forward(self, feats):
x = feats[-1]
for i in range(self.num_convs):
x = self.convs[i](x)
x = self.pool(x)
# multi-class prediction
mc_pred = x.reshape(x.size(0), -1)
mc_pred = self.fc(mc_pred)
return mc_pred, x
@force_fp32(apply_to=('pred', ))
def loss(self, pred, labels):
labels = [lbl.unique() for lbl in labels]
targets = pred.new_zeros(pred.size())
for i, label in enumerate(labels):
targets[i, label] = 1.0
loss = self.loss_weight * self.criterion(pred, targets)
return loss