class X3D(nn.Module):
"""X3D backbone. https://arxiv.org/pdf/2004.04730.pdf.
Args:
gamma_w (float): Global channel width expansion factor. Default: 1.
gamma_b (float): Bottleneck channel width expansion factor. Default: 1.
gamma_d (float): Network depth expansion factor. Default: 1.
pretrained (str | None): Name of pretrained model. Default: None.
in_channels (int): Channel num of input features. Default: 3.
num_stages (int): Resnet stages. Default: 4.
spatial_strides (Sequence[int]):
Spatial strides of residual blocks of each stage.
Default: ``(1, 2, 2, 2)``.
frozen_stages (int): Stages to be frozen (all param fixed). If set to
-1, it means not freezing any parameters. Default: -1.
se_style (str): The style of inserting SE modules into BlockX3D, 'half'
denotes insert into half of the blocks, while 'all' denotes insert
into all blocks. Default: 'half'.
se_ratio (float | None): The reduction ratio of squeeze and excitation
unit. If set as None, it means not using SE unit. Default: 1 / 16.
use_swish (bool): Whether to use swish as the activation function
before and after the 3x3x3 conv. Default: True.
conv_cfg (dict): Config for conv layers. required keys are ``type``
Default: ``dict(type='Conv3d')``.
norm_cfg (dict): Config for norm layers. required keys are ``type`` and
``requires_grad``.
Default: ``dict(type='BN3d', requires_grad=True)``.
act_cfg (dict): Config dict for activation layer.
Default: ``dict(type='ReLU', inplace=True)``.
norm_eval (bool): Whether to set BN layers to eval mode, namely, freeze
running stats (mean and var). Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
zero_init_residual (bool):
Whether to use zero initialization for residual block,
Default: True.
kwargs (dict, optional): Key arguments for "make_res_layer".
"""
def __init__(self,
gamma_w=1.0,
gamma_b=1.0,
gamma_d=1.0,
pretrained=None,
in_channels=3,
num_stages=4,
spatial_strides=(2, 2, 2, 2),
frozen_stages=-1,
se_style='half',
se_ratio=1 / 16,
use_swish=True,
conv_cfg=dict(type='Conv3d'),
norm_cfg=dict(type='BN3d', requires_grad=True),
act_cfg=dict(type='ReLU', inplace=True),
norm_eval=False,
with_cp=False,
zero_init_residual=True,
**kwargs):
super().__init__()
self.gamma_w = gamma_w
self.gamma_b = gamma_b
self.gamma_d = gamma_d
self.pretrained = pretrained
self.in_channels = in_channels
# Hard coded, can be changed by gamma_w
self.base_channels = 24
self.stage_blocks = [1, 2, 5, 3]
# apply parameters gamma_w and gamma_d
self.base_channels = self._round_width(self.base_channels,
self.gamma_w)
self.stage_blocks = [
self._round_repeats(x, self.gamma_d) for x in self.stage_blocks
]
self.num_stages = num_stages
assert 1 <= num_stages <= 4
self.spatial_strides = spatial_strides
assert len(spatial_strides) == num_stages
self.frozen_stages = frozen_stages
self.se_style = se_style
assert self.se_style in ['all', 'half']
self.se_ratio = se_ratio
assert (self.se_ratio is None) or (self.se_ratio > 0)
self.use_swish = use_swish
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
self.zero_init_residual = zero_init_residual
self.block = BlockX3D
self.stage_blocks = self.stage_blocks[:num_stages]
self.layer_inplanes = self.base_channels
self._make_stem_layer()
self.res_layers = []
for i, num_blocks in enumerate(self.stage_blocks):
spatial_stride = spatial_strides[i]
inplanes = self.base_channels * 2**i
planes = int(inplanes * self.gamma_b)
res_layer = self.make_res_layer(self.block,
self.layer_inplanes,
inplanes,
planes,
num_blocks,
spatial_stride=spatial_stride,
se_style=self.se_style,
se_ratio=self.se_ratio,
use_swish=self.use_swish,
norm_cfg=self.norm_cfg,
conv_cfg=self.conv_cfg,
act_cfg=self.act_cfg,
with_cp=with_cp,
**kwargs)
self.layer_inplanes = inplanes
layer_name = f'layer{i + 1}'
self.add_module(layer_name, res_layer)
self.res_layers.append(layer_name)
self.feat_dim = self.base_channels * 2**(len(self.stage_blocks) - 1)
self.conv5 = ConvModule(self.feat_dim,
int(self.feat_dim * self.gamma_b),
kernel_size=1,
stride=1,
padding=0,
bias=False,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.feat_dim = int(self.feat_dim * self.gamma_b)
@staticmethod
def _round_width(width, multiplier, min_depth=8, divisor=8):
"""Round width of filters based on width multiplier."""
if not multiplier:
return width
width *= multiplier
min_depth = min_depth or divisor
new_filters = max(min_depth,
int(width + divisor / 2) // divisor * divisor)
if new_filters < 0.9 * width:
new_filters += divisor
return int(new_filters)
@staticmethod
def _round_repeats(repeats, multiplier):
"""Round number of layers based on depth multiplier."""
if not multiplier:
return repeats
return int(math.ceil(multiplier * repeats))
# the module is parameterized with gamma_b
# no temporal_stride
def make_res_layer(self,
block,
layer_inplanes,
inplanes,
planes,
blocks,
spatial_stride=1,
se_style='half',
se_ratio=None,
use_swish=True,
norm_cfg=None,
act_cfg=None,
conv_cfg=None,
with_cp=False,
**kwargs):
"""Build residual layer for ResNet3D.
Args:
block (nn.Module): Residual module to be built.
layer_inplanes (int): Number of channels for the input feature
of the res layer.
inplanes (int): Number of channels for the input feature in each
block, which equals to base_channels * gamma_w.
planes (int): Number of channels for the output feature in each
block, which equals to base_channel * gamma_w * gamma_b.
blocks (int): Number of residual blocks.
spatial_stride (int): Spatial strides in residual and conv layers.
Default: 1.
se_style (str): The style of inserting SE modules into BlockX3D,
'half' denotes insert into half of the blocks, while 'all'
denotes insert into all blocks. Default: 'half'.
se_ratio (float | None): The reduction ratio of squeeze and
excitation unit. If set as None, it means not using SE unit.
Default: None.
use_swish (bool): Whether to use swish as the activation function
before and after the 3x3x3 conv. Default: True.
conv_cfg (dict | None): Config for norm layers. Default: None.
norm_cfg (dict | None): Config for norm layers. Default: None.
act_cfg (dict | None): Config for activate layers. Default: None.
with_cp (bool | None): Use checkpoint or not. Using checkpoint
will save some memory while slowing down the training speed.
Default: False.
Returns:
nn.Module: A residual layer for the given config.
"""
downsample = None
if spatial_stride != 1 or layer_inplanes != inplanes:
downsample = ConvModule(layer_inplanes,
inplanes,
kernel_size=1,
stride=(1, spatial_stride, spatial_stride),
padding=0,
bias=False,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=None)
use_se = [False] * blocks
if self.se_style == 'all':
use_se = [True] * blocks
elif self.se_style == 'half':
use_se = [i % 2 == 0 for i in range(blocks)]
else:
raise NotImplementedError
layers = []
layers.append(
block(layer_inplanes,
planes,
inplanes,
spatial_stride=spatial_stride,
downsample=downsample,
se_ratio=se_ratio if use_se[0] else None,
use_swish=use_swish,
norm_cfg=norm_cfg,
conv_cfg=conv_cfg,
act_cfg=act_cfg,
with_cp=with_cp,
**kwargs))
for i in range(1, blocks):
layers.append(
block(inplanes,
planes,
inplanes,
spatial_stride=1,
se_ratio=se_ratio if use_se[i] else None,
use_swish=use_swish,
norm_cfg=norm_cfg,
conv_cfg=conv_cfg,
act_cfg=act_cfg,
with_cp=with_cp,
**kwargs))
return nn.Sequential(*layers)
def _make_stem_layer(self):
"""Construct the stem layers consists of a conv+norm+act module and a
pooling layer."""
self.conv1_s = ConvModule(self.in_channels,
self.base_channels,
kernel_size=(1, 3, 3),
stride=(1, 2, 2),
padding=(0, 1, 1),
bias=False,
conv_cfg=self.conv_cfg,
norm_cfg=None,
act_cfg=None)
self.conv1_t = ConvModule(self.base_channels,
self.base_channels,
kernel_size=(5, 1, 1),
stride=(1, 1, 1),
padding=(2, 0, 0),
groups=self.base_channels,
bias=False,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
def _freeze_stages(self):
"""Prevent all the parameters from being optimized before
``self.frozen_stages``."""
if self.frozen_stages >= 0:
self.conv1_s.eval()
self.conv1_t.eval()
for param in self.conv1_s.parameters():
param.requires_grad = False
for param in self.conv1_t.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
m = getattr(self, f'layer{i}')
m.eval()
for param in m.parameters():
param.requires_grad = False
def init_weights(self):
"""Initiate the parameters either from existing checkpoint or from
scratch."""
if isinstance(self.pretrained, str):
logger = get_root_logger()
logger.info(f'load model from: {self.pretrained}')
load_checkpoint(self, self.pretrained, strict=False, logger=logger)
elif self.pretrained is None:
for m in self.modules():
if isinstance(m, nn.Conv3d):
kaiming_init(m)
elif isinstance(m, _BatchNorm):
constant_init(m, 1)
if self.zero_init_residual:
for m in self.modules():
if isinstance(m, BlockX3D):
constant_init(m.conv3.bn, 0)
else:
raise TypeError('pretrained must be a str or None')
def forward(self, x):
"""Defines the computation performed at every call.
Args:
x (torch.Tensor): The input data.
Returns:
torch.Tensor: The feature of the input
samples extracted by the backbone.
"""
x = self.conv1_s(x)
x = self.conv1_t(x)
for layer_name in self.res_layers:
res_layer = getattr(self, layer_name)
x = res_layer(x)
x = self.conv5(x)
return x
def train(self, mode=True):
"""Set the optimization status when training."""
super().train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
class MobileNetV2(nn.Module):
"""MobileNetV2 backbone.
Args:
widen_factor (float): Width multiplier, multiply number of
channels in each layer by this amount. Default: 1.0.
strides (Sequence[int], optional): Strides of the first block of each
layer. If not specified, default config in ``arch_setting`` will
be used.
dilations (Sequence[int]): Dilation of each layer.
out_indices (None or Sequence[int]): Output from which stages.
Default: (7, ).
frozen_stages (int): Stages to be frozen (all param fixed).
Default: -1, which means not freezing any parameters.
conv_cfg (dict): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
act_cfg (dict): Config dict for activation layer.
Default: dict(type='ReLU6').
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
"""
# Parameters to build layers. 3 parameters are needed to construct a
# layer, from left to right: expand_ratio, channel, num_blocks.
arch_settings = [[1, 16, 1], [6, 24, 2], [6, 32, 3], [6, 64, 4],
[6, 96, 3], [6, 160, 3], [6, 320, 1]]
def __init__(self,
widen_factor=1.,
strides=(1, 2, 2, 2, 1, 2, 1),
dilations=(1, 1, 1, 1, 1, 1, 1),
out_indices=(1, 2, 4, 6),
frozen_stages=-1,
conv_cfg=None,
norm_cfg=dict(type='BN'),
act_cfg=dict(type='ReLU6'),
norm_eval=False,
with_cp=False):
super(MobileNetV2, self).__init__()
self.widen_factor = widen_factor
self.strides = strides
self.dilations = dilations
assert len(strides) == len(dilations) == len(self.arch_settings)
self.out_indices = out_indices
for index in out_indices:
if index not in range(0, 7):
raise ValueError('the item in out_indices must in '
f'range(0, 7). But received {index}')
if frozen_stages not in range(-1, 7):
raise ValueError('frozen_stages must be in range(-1, 7). '
f'But received {frozen_stages}')
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
self.in_channels = make_divisible(32 * widen_factor, 8)
self.conv1 = ConvModule(in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.layers = []
for i, layer_cfg in enumerate(self.arch_settings):
expand_ratio, channel, num_blocks = layer_cfg
stride = self.strides[i]
dilation = self.dilations[i]
out_channels = make_divisible(channel * widen_factor, 8)
inverted_res_layer = self.make_layer(out_channels=out_channels,
num_blocks=num_blocks,
stride=stride,
dilation=dilation,
expand_ratio=expand_ratio)
layer_name = f'layer{i + 1}'
self.add_module(layer_name, inverted_res_layer)
self.layers.append(layer_name)
def make_layer(self, out_channels, num_blocks, stride, dilation,
expand_ratio):
"""Stack InvertedResidual blocks to build a layer for MobileNetV2.
Args:
out_channels (int): out_channels of block.
num_blocks (int): Number of blocks.
stride (int): Stride of the first block.
dilation (int): Dilation of the first block.
expand_ratio (int): Expand the number of channels of the
hidden layer in InvertedResidual by this ratio.
"""
layers = []
for i in range(num_blocks):
layers.append(
InvertedResidual(self.in_channels,
out_channels,
stride if i == 0 else 1,
expand_ratio=expand_ratio,
dilation=dilation if i == 0 else 1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp))
self.in_channels = out_channels
return nn.Sequential(*layers)
def init_weights(self, pretrained=None):
if isinstance(pretrained, str):
logger = logging.getLogger()
load_checkpoint(self, pretrained, strict=False, logger=logger)
elif pretrained is None:
for m in self.modules():
if isinstance(m, nn.Conv2d):
kaiming_init(m)
elif isinstance(m, (_BatchNorm, nn.GroupNorm)):
constant_init(m, 1)
else:
raise TypeError('pretrained must be a str or None')
def forward(self, x):
x = self.conv1(x)
outs = []
for i, layer_name in enumerate(self.layers):
layer = getattr(self, layer_name)
x = layer(x)
if i in self.out_indices:
outs.append(x)
if len(outs) == 1:
return outs[0]
else:
return tuple(outs)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
layer = getattr(self, f'layer{i}')
layer.eval()
for param in layer.parameters():
param.requires_grad = False
def train(self, mode=True):
super(MobileNetV2, self).train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
class WeightNet(BaseBackbone):
"""WeightNet (adapted from ShuffleNetV2) backbone.
Args:
widen_factor (float): Width multiplier - adjusts the number of
channels in each layer by this amount. Default: 1.0.
out_indices (Sequence[int]): Output from which stages.
Default: (0, 1, 2, 3).
frozen_stages (int): Stages to be frozen (all param fixed).
Default: -1, which means not freezing any parameters.
conv_cfg (dict, optional): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
act_cfg (dict): Config dict for activation layer.
Default: dict(type='ReLU').
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
"""
def __init__(
self,
widen_factor=1.0,
out_indices=(3, ),
frozen_stages=-1,
conv_cfg=None,
norm_cfg=dict(type="BN"),
act_cfg=dict(type="ReLU"),
norm_eval=False,
with_cp=False,
):
super(WeightNet, self).__init__()
self.stage_blocks = [4, 8, 4]
for index in out_indices:
if index not in range(0, 4):
raise ValueError("the item in out_indices must in "
f"range(0, 4). But received {index}")
if frozen_stages not in range(-1, 4):
raise ValueError("frozen_stages must be in range(-1, 4). "
f"But received {frozen_stages}")
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
if widen_factor == 0.5:
channels = [48, 96, 192, 1024]
elif widen_factor == 1.0:
channels = [116, 232, 464, 1024]
elif widen_factor == 1.5:
channels = [176, 352, 704, 1024]
elif widen_factor == 2.0:
channels = [244, 488, 976, 2048]
else:
raise ValueError("widen_factor must be in [0.5, 1.0, 1.5, 2.0]. "
f"But received {widen_factor}")
self.in_channels = 24
self.conv1 = ConvModule(
in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=act_cfg,
)
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.layers = nn.ModuleList()
for i, num_blocks in enumerate(self.stage_blocks):
layer = self._make_layer(channels[i], num_blocks)
self.layers.append(layer)
output_channels = channels[-1]
self.layers.append(
ConvModule(
in_channels=self.in_channels,
out_channels=output_channels,
kernel_size=1,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=act_cfg,
))
def _make_layer(self, out_channels, num_blocks):
"""Stack blocks to make a layer.
Args:
out_channels (int): out_channels of the block.
num_blocks (int): number of blocks.
"""
layers = []
for i in range(num_blocks):
if i == 0:
layers.append(
InvertedResidual(
in_channels=self.in_channels,
out_channels=out_channels,
stride=2,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp,
))
self.in_channels = out_channels
else:
layers.append(
InvertedResidual(
in_channels=self.in_channels // 2,
out_channels=out_channels,
stride=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp,
))
return nn.Sequential(*layers)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(self.frozen_stages):
m = self.layers[i]
m.eval()
for param in m.parameters():
param.requires_grad = False
def init_weights(self, pretrained=None):
if isinstance(pretrained, str):
logger = logging.getLogger()
load_checkpoint(self, pretrained, strict=False, logger=logger)
elif pretrained is None:
for name, m in self.named_modules():
if isinstance(m, nn.Conv2d):
if "conv1" in name:
normal_init(m, mean=0, std=0.01)
else:
normal_init(m, mean=0, std=1.0 / m.weight.shape[1])
elif isinstance(m, (_BatchNorm, nn.GroupNorm)):
constant_init(m.weight, val=1, bias=0.0001)
if isinstance(m, _BatchNorm):
if m.running_mean is not None:
nn.init.constant_(m.running_mean, 0)
else:
raise TypeError("pretrained must be a str or None. But received "
f"{type(pretrained)}")
def forward(self, x):
x = self.conv1(x)
x = self.maxpool(x)
outs = []
for i, layer in enumerate(self.layers):
x = layer(x)
if i in self.out_indices:
outs.append(x)
if len(outs) == 1:
return outs[0]
else:
return tuple(outs)
def train(self, mode=True):
super(WeightNet, self).train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, nn.BatchNorm2d):
m.eval()
class ShuffleNetV1(BaseBackbone):
"""ShuffleNetV1 backbone.
Args:
groups (int): The number of groups to be used in grouped 1x1
convolutions in each ShuffleUnit. Default: 3.
widen_factor (float): Width multiplier - adjusts the number
of channels in each layer by this amount. Default: 1.0.
out_indices (Sequence[int]): Output from which stages.
Default: (2, )
frozen_stages (int): Stages to be frozen (all param fixed).
Default: -1, which means not freezing any parameters.
conv_cfg (dict, optional): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
act_cfg (dict): Config dict for activation layer.
Default: dict(type='ReLU').
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
"""
def __init__(self,
groups=3,
widen_factor=1.0,
out_indices=(2, ),
frozen_stages=-1,
conv_cfg=None,
norm_cfg=dict(type='BN'),
act_cfg=dict(type='ReLU'),
norm_eval=False,
with_cp=False):
super(ShuffleNetV1, self).__init__()
self.stage_blocks = [4, 8, 4]
self.groups = groups
for index in out_indices:
if index not in range(0, 3):
raise ValueError('the item in out_indices must in '
f'range(0, 3). But received {index}')
if frozen_stages not in range(-1, 3):
raise ValueError('frozen_stages must be in range(-1, 3). '
f'But received {frozen_stages}')
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
if groups == 1:
channels = (144, 288, 576)
elif groups == 2:
channels = (200, 400, 800)
elif groups == 3:
channels = (240, 480, 960)
elif groups == 4:
channels = (272, 544, 1088)
elif groups == 8:
channels = (384, 768, 1536)
else:
raise ValueError(f'{groups} groups is not supported for 1x1 '
'Grouped Convolutions')
channels = [make_divisible(ch * widen_factor, 8) for ch in channels]
self.in_channels = int(24 * widen_factor)
self.conv1 = ConvModule(in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=act_cfg)
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.layers = nn.ModuleList()
for i, num_blocks in enumerate(self.stage_blocks):
first_block = True if i == 0 else False
layer = self.make_layer(channels[i], num_blocks, first_block)
self.layers.append(layer)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(self.frozen_stages):
layer = self.layers[i]
layer.eval()
for param in layer.parameters():
param.requires_grad = False
def init_weights(self, pretrained=None):
if isinstance(pretrained, str):
logger = logging.getLogger()
load_checkpoint(self, pretrained, strict=False, logger=logger)
elif pretrained is None:
for name, m in self.named_modules():
if isinstance(m, nn.Conv2d):
if 'conv1' in name:
normal_init(m, mean=0, std=0.01)
else:
normal_init(m, mean=0, std=1.0 / m.weight.shape[1])
elif isinstance(m, (_BatchNorm, nn.GroupNorm)):
constant_init(m.weight, val=1, bias=0.0001)
if isinstance(m, _BatchNorm):
if m.running_mean is not None:
nn.init.constant_(m.running_mean, 0)
else:
raise TypeError('pretrained must be a str or None. But received '
f'{type(pretrained)}')
def make_layer(self, out_channels, num_blocks, first_block=False):
""" Stack ShuffleUnit blocks to make a layer.
Args:
out_channels (int): out_channels of the block.
num_blocks (int): Number of blocks.
first_block (bool): Whether is the first ShuffleUnit of a
sequential ShuffleUnits. Default: False, which means not using
the grouped 1x1 convolution.
"""
layers = []
for i in range(num_blocks):
first_block = first_block if i == 0 else False
combine_mode = 'concat' if i == 0 else 'add'
layers.append(
ShuffleUnit(self.in_channels,
out_channels,
groups=self.groups,
first_block=first_block,
combine=combine_mode,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp))
self.in_channels = out_channels
return nn.Sequential(*layers)
def forward(self, x):
x = self.conv1(x)
x = self.maxpool(x)
outs = []
for i, layer in enumerate(self.layers):
x = layer(x)
if i in self.out_indices:
outs.append(x)
if len(outs) == 1:
return outs[0]
else:
return tuple(outs)
def train(self, mode=True):
super(ShuffleNetV1, self).train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
class ResNet3d(nn.Module):
"""ResNet 3d backbone.
Args:
depth (int): Depth of resnet, from {18, 34, 50, 101, 152}.
pretrained (str | None): Name of pretrained model.
pretrained2d (bool): Whether to load pretrained 2D model.
Default: True.
in_channels (int): Channel num of input features. Default: 3.
base_channels (int): Channel num of stem output features. Default: 64.
out_indices (Sequence[int]): Indices of output feature. Default: (3, ).
num_stages (int): Resnet stages. Default: 4.
spatial_strides (Sequence[int]):
Spatial strides of residual blocks of each stage.
Default: ``(1, 2, 2, 2)``.
temporal_strides (Sequence[int]):
Temporal strides of residual blocks of each stage.
Default: ``(1, 1, 1, 1)``.
dilations (Sequence[int]): Dilation of each stage.
Default: ``(1, 1, 1, 1)``.
conv1_kernel (Sequence[int]): Kernel size of the first conv layer.
Default: ``(5, 7, 7)``.
conv1_stride_t (int): Temporal stride of the first conv layer.
Default: 2.
pool1_stride_t (int): Temporal stride of the first pooling layer.
Default: 2.
with_pool2 (bool): Whether to use pool2. Default: True.
style (str): `pytorch` or `caffe`. If set to "pytorch", the stride-two
layer is the 3x3 conv layer, otherwise the stride-two layer is
the first 1x1 conv layer. Default: 'pytorch'.
frozen_stages (int): Stages to be frozen (all param fixed). -1 means
not freezing any parameters. Default: -1.
inflate (Sequence[int]): Inflate Dims of each block.
Default: (1, 1, 1, 1).
inflate_style (str): ``3x1x1`` or ``1x1x1``. which determines the
kernel sizes and padding strides for conv1 and conv2 in each block.
Default: '3x1x1'.
conv_cfg (dict): Config for conv layers. required keys are ``type``
Default: ``dict(type='Conv3d')``.
norm_cfg (dict): Config for norm layers. required keys are ``type`` and
``requires_grad``.
Default: ``dict(type='BN3d', requires_grad=True)``.
act_cfg (dict): Config dict for activation layer.
Default: ``dict(type='ReLU', inplace=True)``.
norm_eval (bool): Whether to set BN layers to eval mode, namely, freeze
running stats (mean and var). Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
non_local (Sequence[int]): Determine whether to apply non-local module
in the corresponding block of each stages. Default: (0, 0, 0, 0).
non_local_cfg (dict): Config for non-local module. Default: ``dict()``.
zero_init_residual (bool):
Whether to use zero initialization for residual block,
Default: True.
kwargs (dict, optional): Key arguments for "make_res_layer".
"""
arch_settings = {
18: (BasicBlock3d, (2, 2, 2, 2)),
34: (BasicBlock3d, (3, 4, 6, 3)),
50: (Bottleneck3d, (3, 4, 6, 3)),
101: (Bottleneck3d, (3, 4, 23, 3)),
152: (Bottleneck3d, (3, 8, 36, 3))
}
def __init__(self,
depth,
pretrained,
pretrained2d=True,
in_channels=3,
num_stages=4,
base_channels=64,
out_indices=(3, ),
spatial_strides=(1, 2, 2, 2),
temporal_strides=(1, 1, 1, 1),
dilations=(1, 1, 1, 1),
conv1_kernel=(5, 7, 7),
conv1_stride_t=2,
pool1_stride_t=2,
with_pool2=True,
style='pytorch',
frozen_stages=-1,
inflate=(1, 1, 1, 1),
inflate_style='3x1x1',
conv_cfg=dict(type='Conv3d'),
norm_cfg=dict(type='BN3d', requires_grad=True),
act_cfg=dict(type='ReLU', inplace=True),
norm_eval=False,
with_cp=False,
non_local=(0, 0, 0, 0),
non_local_cfg=dict(),
zero_init_residual=True,
**kwargs):
super().__init__()
if depth not in self.arch_settings:
raise KeyError(f'invalid depth {depth} for resnet')
self.depth = depth
self.pretrained = pretrained
self.pretrained2d = pretrained2d
self.in_channels = in_channels
self.base_channels = base_channels
self.num_stages = num_stages
assert 1 <= num_stages <= 4
self.out_indices = out_indices
assert max(out_indices) < num_stages
self.spatial_strides = spatial_strides
self.temporal_strides = temporal_strides
self.dilations = dilations
assert len(spatial_strides) == len(temporal_strides) == len(
dilations) == num_stages
self.conv1_kernel = conv1_kernel
self.conv1_stride_t = conv1_stride_t
self.pool1_stride_t = pool1_stride_t
self.with_pool2 = with_pool2
self.style = style
self.frozen_stages = frozen_stages
self.stage_inflations = _ntuple(num_stages)(inflate)
self.non_local_stages = _ntuple(num_stages)(non_local)
self.inflate_style = inflate_style
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
self.zero_init_residual = zero_init_residual
self.block, stage_blocks = self.arch_settings[depth]
self.stage_blocks = stage_blocks[:num_stages]
self.inplanes = self.base_channels
self.non_local_cfg = non_local_cfg
self._make_stem_layer()
self.res_layers = []
for i, num_blocks in enumerate(self.stage_blocks):
spatial_stride = spatial_strides[i]
temporal_stride = temporal_strides[i]
dilation = dilations[i]
planes = self.base_channels * 2**i
res_layer = self.make_res_layer(self.block,
self.inplanes,
planes,
num_blocks,
spatial_stride=spatial_stride,
temporal_stride=temporal_stride,
dilation=dilation,
style=self.style,
norm_cfg=self.norm_cfg,
conv_cfg=self.conv_cfg,
act_cfg=self.act_cfg,
non_local=self.non_local_stages[i],
non_local_cfg=self.non_local_cfg,
inflate=self.stage_inflations[i],
inflate_style=self.inflate_style,
with_cp=with_cp,
**kwargs)
self.inplanes = planes * self.block.expansion
layer_name = f'layer{i + 1}'
self.add_module(layer_name, res_layer)
self.res_layers.append(layer_name)
self.feat_dim = self.block.expansion * self.base_channels * 2**(
len(self.stage_blocks) - 1)
@staticmethod
def make_res_layer(block,
inplanes,
planes,
blocks,
spatial_stride=1,
temporal_stride=1,
dilation=1,
style='pytorch',
inflate=1,
inflate_style='3x1x1',
non_local=0,
non_local_cfg=dict(),
norm_cfg=None,
act_cfg=None,
conv_cfg=None,
with_cp=False,
**kwargs):
"""Build residual layer for ResNet3D.
Args:
block (nn.Module): Residual module to be built.
inplanes (int): Number of channels for the input feature
in each block.
planes (int): Number of channels for the output feature
in each block.
blocks (int): Number of residual blocks.
spatial_stride (int | Sequence[int]): Spatial strides in
residual and conv layers. Default: 1.
temporal_stride (int | Sequence[int]): Temporal strides in
residual and conv layers. Default: 1.
dilation (int): Spacing between kernel elements. Default: 1.
style (str): ``pytorch`` or ``caffe``. If set to ``pytorch``,
the stride-two layer is the 3x3 conv layer, otherwise
the stride-two layer is the first 1x1 conv layer.
Default: ``pytorch``.
inflate (int | Sequence[int]): Determine whether to inflate
for each block. Default: 1.
inflate_style (str): ``3x1x1`` or ``1x1x1``. which determines
the kernel sizes and padding strides for conv1 and conv2
in each block. Default: '3x1x1'.
non_local (int | Sequence[int]): Determine whether to apply
non-local module in the corresponding block of each stages.
Default: 0.
non_local_cfg (dict): Config for non-local module.
Default: ``dict()``.
conv_cfg (dict | None): Config for norm layers. Default: None.
norm_cfg (dict | None): Config for norm layers. Default: None.
act_cfg (dict | None): Config for activate layers. Default: None.
with_cp (bool | None): Use checkpoint or not. Using checkpoint
will save some memory while slowing down the training speed.
Default: False.
Returns:
nn.Module: A residual layer for the given config.
"""
inflate = inflate if not isinstance(inflate,
int) else (inflate, ) * blocks
non_local = non_local if not isinstance(
non_local, int) else (non_local, ) * blocks
assert len(inflate) == blocks and len(non_local) == blocks
downsample = None
if spatial_stride != 1 or inplanes != planes * block.expansion:
downsample = ConvModule(inplanes,
planes * block.expansion,
kernel_size=1,
stride=(temporal_stride, spatial_stride,
spatial_stride),
bias=False,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=None)
layers = []
layers.append(
block(inplanes,
planes,
spatial_stride=spatial_stride,
temporal_stride=temporal_stride,
dilation=dilation,
downsample=downsample,
style=style,
inflate=(inflate[0] == 1),
inflate_style=inflate_style,
non_local=(non_local[0] == 1),
non_local_cfg=non_local_cfg,
norm_cfg=norm_cfg,
conv_cfg=conv_cfg,
act_cfg=act_cfg,
with_cp=with_cp,
**kwargs))
inplanes = planes * block.expansion
for i in range(1, blocks):
layers.append(
block(inplanes,
planes,
spatial_stride=1,
temporal_stride=1,
dilation=dilation,
style=style,
inflate=(inflate[i] == 1),
inflate_style=inflate_style,
non_local=(non_local[i] == 1),
non_local_cfg=non_local_cfg,
norm_cfg=norm_cfg,
conv_cfg=conv_cfg,
act_cfg=act_cfg,
with_cp=with_cp,
**kwargs))
return nn.Sequential(*layers)
@staticmethod
def _inflate_conv_params(conv3d, state_dict_2d, module_name_2d,
inflated_param_names):
"""Inflate a conv module from 2d to 3d.
Args:
conv3d (nn.Module): The destination conv3d module.
state_dict_2d (OrderedDict): The state dict of pretrained 2d model.
module_name_2d (str): The name of corresponding conv module in the
2d model.
inflated_param_names (list[str]): List of parameters that have been
inflated.
"""
weight_2d_name = module_name_2d + '.weight'
conv2d_weight = state_dict_2d[weight_2d_name]
kernel_t = conv3d.weight.data.shape[2]
new_weight = conv2d_weight.data.unsqueeze(2).expand_as(
conv3d.weight) / kernel_t
conv3d.weight.data.copy_(new_weight)
inflated_param_names.append(weight_2d_name)
if getattr(conv3d, 'bias') is not None:
bias_2d_name = module_name_2d + '.bias'
conv3d.bias.data.copy_(state_dict_2d[bias_2d_name])
inflated_param_names.append(bias_2d_name)
@staticmethod
def _inflate_bn_params(bn3d, state_dict_2d, module_name_2d,
inflated_param_names):
"""Inflate a norm module from 2d to 3d.
Args:
bn3d (nn.Module): The destination bn3d module.
state_dict_2d (OrderedDict): The state dict of pretrained 2d model.
module_name_2d (str): The name of corresponding bn module in the
2d model.
inflated_param_names (list[str]): List of parameters that have been
inflated.
"""
for param_name, param in bn3d.named_parameters():
param_2d_name = f'{module_name_2d}.{param_name}'
param_2d = state_dict_2d[param_2d_name]
param.data.copy_(param_2d)
inflated_param_names.append(param_2d_name)
for param_name, param in bn3d.named_buffers():
param_2d_name = f'{module_name_2d}.{param_name}'
# some buffers like num_batches_tracked may not exist in old
# checkpoints
if param_2d_name in state_dict_2d:
param_2d = state_dict_2d[param_2d_name]
param.data.copy_(param_2d)
inflated_param_names.append(param_2d_name)
@staticmethod
def _inflate_weights(self, logger):
"""Inflate the resnet2d parameters to resnet3d.
The differences between resnet3d and resnet2d mainly lie in an extra
axis of conv kernel. To utilize the pretrained parameters in 2d model,
the weight of conv2d models should be inflated to fit in the shapes of
the 3d counterpart.
Args:
logger (logging.Logger): The logger used to print
debugging infomation.
"""
state_dict_r2d = _load_checkpoint(self.pretrained)
if 'state_dict' in state_dict_r2d:
state_dict_r2d = state_dict_r2d['state_dict']
inflated_param_names = []
for name, module in self.named_modules():
if isinstance(module, ConvModule):
# we use a ConvModule to wrap conv+bn+relu layers, thus the
# name mapping is needed
if 'downsample' in name:
# layer{X}.{Y}.downsample.conv->layer{X}.{Y}.downsample.0
original_conv_name = name + '.0'
# layer{X}.{Y}.downsample.bn->layer{X}.{Y}.downsample.1
original_bn_name = name + '.1'
else:
# layer{X}.{Y}.conv{n}.conv->layer{X}.{Y}.conv{n}
original_conv_name = name
# layer{X}.{Y}.conv{n}.bn->layer{X}.{Y}.bn{n}
original_bn_name = name.replace('conv', 'bn')
if original_conv_name + '.weight' not in state_dict_r2d:
logger.warning(f'Module not exist in the state_dict_r2d'
f': {original_conv_name}')
else:
shape_2d = state_dict_r2d[original_conv_name +
'.weight'].shape
shape_3d = module.conv.weight.data.shape
if shape_2d != shape_3d[:2] + shape_3d[3:]:
logger.warning(f'Weight shape mismatch for '
f': {original_conv_name} : '
f'3d weight shape: {shape_3d}; '
f'2d weight shape: {shape_2d}. ')
else:
self._inflate_conv_params(module.conv, state_dict_r2d,
original_conv_name,
inflated_param_names)
if original_bn_name + '.weight' not in state_dict_r2d:
logger.warning(f'Module not exist in the state_dict_r2d'
f': {original_bn_name}')
else:
self._inflate_bn_params(module.bn, state_dict_r2d,
original_bn_name,
inflated_param_names)
# check if any parameters in the 2d checkpoint are not loaded
remaining_names = set(
state_dict_r2d.keys()) - set(inflated_param_names)
if remaining_names:
logger.info(f'These parameters in the 2d checkpoint are not loaded'
f': {remaining_names}')
def inflate_weights(self, logger):
self._inflate_weights(self, logger)
def _make_stem_layer(self):
"""Construct the stem layers consists of a conv+norm+act module and a
pooling layer."""
self.conv1 = ConvModule(self.in_channels,
self.base_channels,
kernel_size=self.conv1_kernel,
stride=(self.conv1_stride_t, 2, 2),
padding=tuple([
(k - 1) // 2
for k in _triple(self.conv1_kernel)
]),
bias=False,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.maxpool = nn.MaxPool3d(kernel_size=(1, 3, 3),
stride=(self.pool1_stride_t, 2, 2),
padding=(0, 1, 1))
self.pool2 = nn.MaxPool3d(kernel_size=(2, 1, 1), stride=(2, 1, 1))
def _freeze_stages(self):
"""Prevent all the parameters from being optimized before
``self.frozen_stages``."""
if self.frozen_stages >= 0:
self.conv1.eval()
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
m = getattr(self, f'layer{i}')
m.eval()
for param in m.parameters():
param.requires_grad = False
@staticmethod
def _init_weights(self, pretrained=None):
"""Initiate the parameters either from existing checkpoint or from
scratch.
Args:
pretrained (str | None): The path of the pretrained weight. Will
override the original `pretrained` if set. The arg is added to
be compatible with mmdet. Default: None.
"""
if pretrained:
self.pretrained = pretrained
if isinstance(self.pretrained, str):
logger = get_root_logger()
logger.info(f'load model from: {self.pretrained}')
if self.pretrained2d:
# Inflate 2D model into 3D model.
self.inflate_weights(logger)
else:
# Directly load 3D model.
load_checkpoint(self,
self.pretrained,
strict=False,
logger=logger)
elif self.pretrained is None:
for m in self.modules():
if isinstance(m, nn.Conv3d):
kaiming_init(m)
elif isinstance(m, _BatchNorm):
constant_init(m, 1)
if self.zero_init_residual:
for m in self.modules():
if isinstance(m, Bottleneck3d):
constant_init(m.conv3.bn, 0)
elif isinstance(m, BasicBlock3d):
constant_init(m.conv2.bn, 0)
else:
raise TypeError('pretrained must be a str or None')
def init_weights(self, pretrained=None):
self._init_weights(self, pretrained)
def forward(self, x):
"""Defines the computation performed at every call.
Args:
x (torch.Tensor): The input data.
Returns:
torch.Tensor: The feature of the input
samples extracted by the backbone.
"""
x = self.conv1(x)
x = self.maxpool(x)
outs = []
for i, layer_name in enumerate(self.res_layers):
res_layer = getattr(self, layer_name)
x = res_layer(x)
if i == 0 and self.with_pool2:
x = self.pool2(x)
if i in self.out_indices:
outs.append(x)
if len(outs) == 1:
return outs[0]
return tuple(outs)
def train(self, mode=True):
"""Set the optimization status when training."""
super().train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
class MobileNetV2(BaseModule):
"""MobileNetV2 backbone.
Args:
widen_factor (float): Width multiplier, multiply number of
channels in each layer by this amount. Default: 1.0.
out_indices (Sequence[int], optional): Output from which stages.
Default: (1, 2, 4, 7).
frozen_stages (int): Stages to be frozen (all param fixed).
Default: -1, which means not freezing any parameters.
conv_cfg (dict, optional): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
act_cfg (dict): Config dict for activation layer.
Default: dict(type='ReLU6').
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
pretrained (str, optional): model pretrained path. Default: None
init_cfg (dict or list[dict], optional): Initialization config dict.
Default: None
"""
# Parameters to build layers. 4 parameters are needed to construct a
# layer, from left to right: expand_ratio, channel, num_blocks, stride.
arch_settings = [[1, 16, 1, 1], [6, 24, 2, 2], [6, 32, 3, 2],
[6, 64, 4, 2], [6, 96, 3, 1], [6, 160, 3, 2],
[6, 320, 1, 1]]
def __init__(self,
widen_factor=1.,
out_indices=(1, 2, 4, 7),
frozen_stages=-1,
conv_cfg=None,
norm_cfg=dict(type='BN'),
act_cfg=dict(type='ReLU6'),
norm_eval=False,
with_cp=False,
pretrained=None,
init_cfg=None):
super(MobileNetV2, self).__init__(init_cfg)
self.pretrained = pretrained
assert not (init_cfg and pretrained), \
'init_cfg and pretrained cannot be setting at the same time'
if isinstance(pretrained, str):
warnings.warn('DeprecationWarning: pretrained is deprecated, '
'please use "init_cfg" instead')
self.init_cfg = dict(type='Pretrained', checkpoint=pretrained)
elif pretrained is None:
if init_cfg is None:
self.init_cfg = [
dict(type='Kaiming', layer='Conv2d'),
dict(type='Constant',
val=1,
layer=['_BatchNorm', 'GroupNorm'])
]
else:
raise TypeError('pretrained must be a str or None')
self.widen_factor = widen_factor
self.out_indices = out_indices
if not set(out_indices).issubset(set(range(0, 8))):
raise ValueError('out_indices must be a subset of range'
f'(0, 8). But received {out_indices}')
if frozen_stages not in range(-1, 8):
raise ValueError('frozen_stages must be in range(-1, 8). '
f'But received {frozen_stages}')
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
self.in_channels = make_divisible(32 * widen_factor, 8)
self.conv1 = ConvModule(in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.layers = []
for i, layer_cfg in enumerate(self.arch_settings):
expand_ratio, channel, num_blocks, stride = layer_cfg
out_channels = make_divisible(channel * widen_factor, 8)
inverted_res_layer = self.make_layer(out_channels=out_channels,
num_blocks=num_blocks,
stride=stride,
expand_ratio=expand_ratio)
layer_name = f'layer{i + 1}'
self.add_module(layer_name, inverted_res_layer)
self.layers.append(layer_name)
if widen_factor > 1.0:
self.out_channel = int(1280 * widen_factor)
else:
self.out_channel = 1280
layer = ConvModule(in_channels=self.in_channels,
out_channels=self.out_channel,
kernel_size=1,
stride=1,
padding=0,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.add_module('conv2', layer)
self.layers.append('conv2')
def make_layer(self, out_channels, num_blocks, stride, expand_ratio):
"""Stack InvertedResidual blocks to build a layer for MobileNetV2.
Args:
out_channels (int): out_channels of block.
num_blocks (int): number of blocks.
stride (int): stride of the first block. Default: 1
expand_ratio (int): Expand the number of channels of the
hidden layer in InvertedResidual by this ratio. Default: 6.
"""
layers = []
for i in range(num_blocks):
if i >= 1:
stride = 1
layers.append(
InvertedResidual(self.in_channels,
out_channels,
mid_channels=int(
round(self.in_channels * expand_ratio)),
stride=stride,
with_expand_conv=expand_ratio != 1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp))
self.in_channels = out_channels
return nn.Sequential(*layers)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
layer = getattr(self, f'layer{i}')
layer.eval()
for param in layer.parameters():
param.requires_grad = False
def forward(self, x):
"""Forward function."""
x = self.conv1(x)
outs = []
for i, layer_name in enumerate(self.layers):
layer = getattr(self, layer_name)
x = layer(x)
if i in self.out_indices:
outs.append(x)
return tuple(outs)
def train(self, mode=True):
"""Convert the model into training mode while keep normalization layer
frozen."""
super(MobileNetV2, self).train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
# trick: eval have effect on BatchNorm only
if isinstance(m, _BatchNorm):
m.eval()
class EMAHead(BaseDecodeHead):
"""Expectation Maximization Attention Networks for Semantic Segmentation.
This head is the implementation of `EMANet
<https://arxiv.org/abs/1907.13426>`_.
Args:
ema_channels (int): EMA module channels
num_bases (int): Number of bases.
num_stages (int): Number of the EM iterations.
concat_input (bool): Whether concat the input and output of convs
before classification layer. Default: True
momentum (float): Momentum to update the base. Default: 0.1.
"""
def __init__(self,
ema_channels,
num_bases,
num_stages,
concat_input=True,
momentum=0.1,
**kwargs):
super(EMAHead, self).__init__(**kwargs)
self.ema_channels = ema_channels
self.num_bases = num_bases
self.num_stages = num_stages
self.concat_input = concat_input
self.momentum = momentum
self.ema_module = EMAModule(self.ema_channels, self.num_bases,
self.num_stages, self.momentum)
self.ema_in_conv = ConvModule(
self.in_channels,
self.ema_channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
# project (0, inf) -> (-inf, inf)
self.ema_mid_conv = ConvModule(
self.ema_channels,
self.ema_channels,
1,
conv_cfg=self.conv_cfg,
norm_cfg=None,
act_cfg=None)
for param in self.ema_mid_conv.parameters():
param.requires_grad = False
self.ema_out_conv = ConvModule(
self.ema_channels,
self.ema_channels,
1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=None)
self.bottleneck = ConvModule(
self.ema_channels,
self.channels,
3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
if self.concat_input:
self.conv_cat = ConvModule(
self.in_channels + self.channels,
self.channels,
kernel_size=3,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
def forward(self, inputs):
"""Forward function."""
x = self._transform_inputs(inputs)
feats = self.ema_in_conv(x)
identity = feats
feats = self.ema_mid_conv(feats)
recon = self.ema_module(feats)
recon = F.relu(recon, inplace=True)
recon = self.ema_out_conv(recon)
output = F.relu(identity + recon, inplace=True)
output = self.bottleneck(output)
if self.concat_input:
output = self.conv_cat(torch.cat([x, output], dim=1))
output = self.cls_seg(output)
return output
class MobileNetV3(BaseBackbone):
"""MobileNetV3 backbone.
Args:
arch (str): Architechture of mobilnetv3, from {small, big}.
Default: small.
conv_cfg (dict): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
out_indices (None or Sequence[int]): Output from which stages.
Default: (10, ), which means output tensors from final stage.
frozen_stages (int): Stages to be frozen (all param fixed).
Defualt: -1, which means not freezing any parameters.
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save
some memory while slowing down the training speed.
Defualt: False.
"""
# Parameters to build each block:
# [kernel size, mid channels, out channels, with_se, act type, stride]
arch_settings = {
'small': [[3, 16, 16, True, 'ReLU', 2],
[3, 72, 24, False, 'ReLU', 2],
[3, 88, 24, False, 'ReLU', 1],
[5, 96, 40, True, 'HSwish', 2],
[5, 240, 40, True, 'HSwish', 1],
[5, 240, 40, True, 'HSwish', 1],
[5, 120, 48, True, 'HSwish', 1],
[5, 144, 48, True, 'HSwish', 1],
[5, 288, 96, True, 'HSwish', 2],
[5, 576, 96, True, 'HSwish', 1],
[5, 576, 96, True, 'HSwish', 1]],
'big': [[3, 16, 16, False, 'ReLU', 1],
[3, 64, 24, False, 'ReLU', 2],
[3, 72, 24, False, 'ReLU', 1],
[5, 72, 40, True, 'ReLU', 2],
[5, 120, 40, True, 'ReLU', 1],
[5, 120, 40, True, 'ReLU', 1],
[3, 240, 80, False, 'HSwish', 2],
[3, 200, 80, False, 'HSwish', 1],
[3, 184, 80, False, 'HSwish', 1],
[3, 184, 80, False, 'HSwish', 1],
[3, 480, 112, True, 'HSwish', 1],
[3, 672, 112, True, 'HSwish', 1],
[5, 672, 160, True, 'HSwish', 1],
[5, 672, 160, True, 'HSwish', 2],
[5, 960, 160, True, 'HSwish', 1]]
} # yapf: disable
def __init__(self,
arch='small',
conv_cfg=None,
norm_cfg=dict(type='BN'),
out_indices=(10, ),
frozen_stages=-1,
norm_eval=False,
with_cp=False):
# Protect mutable default arguments
norm_cfg = copy.deepcopy(norm_cfg)
super().__init__()
assert arch in self.arch_settings
for index in out_indices:
if index not in range(0, len(self.arch_settings[arch])):
raise ValueError('the item in out_indices must in '
f'range(0, {len(self.arch_settings[arch])}). '
f'But received {index}')
if frozen_stages not in range(-1, len(self.arch_settings[arch])):
raise ValueError('frozen_stages must be in range(-1, '
f'{len(self.arch_settings[arch])}). '
f'But received {frozen_stages}')
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.arch = arch
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.norm_eval = norm_eval
self.with_cp = with_cp
self.in_channels = 16
self.conv1 = ConvModule(
in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=dict(type='HSwish'))
self.layers = self._make_layer()
self.feat_dim = self.arch_settings[arch][-1][2]
def _make_layer(self):
layers = []
layer_setting = self.arch_settings[self.arch]
for i, params in enumerate(layer_setting):
(kernel_size, mid_channels, out_channels, with_se, act,
stride) = params
if with_se:
se_cfg = dict(
channels=mid_channels,
ratio=4,
act_cfg=(dict(type='ReLU'), dict(type='HSigmoid')))
else:
se_cfg = None
layer = InvertedResidual(
in_channels=self.in_channels,
out_channels=out_channels,
mid_channels=mid_channels,
kernel_size=kernel_size,
stride=stride,
se_cfg=se_cfg,
with_expand_conv=True,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=dict(type=act),
with_cp=self.with_cp)
self.in_channels = out_channels
layer_name = 'layer{}'.format(i + 1)
self.add_module(layer_name, layer)
layers.append(layer_name)
return layers
def init_weights(self, pretrained=None):
if isinstance(pretrained, str):
logger = logging.getLogger()
load_checkpoint(self, pretrained, strict=False, logger=logger)
elif pretrained is None:
for m in self.modules():
if isinstance(m, nn.Conv2d):
kaiming_init(m)
elif isinstance(m, nn.BatchNorm2d):
constant_init(m, 1)
else:
raise TypeError('pretrained must be a str or None')
def forward(self, x):
x = self.conv1(x)
outs = []
for i, layer_name in enumerate(self.layers):
layer = getattr(self, layer_name)
x = layer(x)
if i in self.out_indices:
outs.append(x)
if len(outs) == 1:
return outs[0]
return tuple(outs)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
layer = getattr(self, f'layer{i}')
layer.eval()
for param in layer.parameters():
param.requires_grad = False
def train(self, mode=True):
super().train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
class EfficientNet(nn.Module):
# maps scale to coefficients of (width, depth, dropout)
param_dict = {
0: (1.0, 1.0, 0.2),
1: (1.0, 1.1, 0.2),
2: (1.1, 1.2, 0.3),
3: (1.2, 1.4, 0.3),
4: (1.4, 1.8, 0.4),
5: (1.6, 2.2, 0.4),
6: (1.8, 2.6, 0.5),
7: (2.0, 3.1, 0.5),
}
def __init__(self,
in_channels: int = 3,
n_classes: int = 13,
scale: int = 1,
se_rate: float = 0.25,
drop_connect_rate: float = 0.2,
frozen_stages: int = -1,
norm_cfg=dict(type='SyncBN', momentum=0.01, eps=1e-3),
act_cfg=dict(type='Swish'),
pretrained=None):
super(EfficientNet, self).__init__()
assert scale in range(0, 8)
self.frozen_stages = frozen_stages
self.in_channels = in_channels
width_coefficient, depth_coefficient, dropout_rate = self.param_dict[
scale]
self.width_coefficient = width_coefficient
self.depth_coefficient = depth_coefficient
self.divisor = 8
self.n_classes = n_classes
self.pretrained = pretrained
list_channels = [32, 16, 24, 40, 80, 112, 192, 320, 1280]
list_channels = [self._setup_channels(c) for c in list_channels]
self.list_channels = list_channels
list_num_repeats = [1, 2, 2, 3, 3, 4, 1]
list_num_repeats = [self._setup_repeats(r) for r in list_num_repeats]
self.list_num_repeats = list_num_repeats
expand_rates = [1, 6, 6, 6, 6, 6, 6]
strides = [1, 2, 2, 2, 1, 2, 1]
kernel_sizes = [3, 3, 5, 3, 5, 5, 3]
# Define stem
self.stem = ConvModule(in_channels=self.in_channels,
out_channels=self.list_channels[0],
kernel_size=3,
stride=2,
padding=1,
bias=False,
norm_cfg=norm_cfg,
act_cfg=act_cfg)
# Define blocks
blocks = []
counter = 0
num_blocks = sum(self.list_num_repeats)
for idx in range(7):
num_channels = self.list_channels[idx]
next_num_channels = self.list_channels[idx + 1]
num_repeats = self.list_num_repeats[idx]
expand_rate = expand_rates[idx]
kernel_size = kernel_sizes[idx]
stride = strides[idx]
# drop rate increases as depth increases
drop_rate = drop_connect_rate * counter / num_blocks
name = 'MBConv{}_{}'.format(expand_rate, counter)
blocks.append((name,
MBConv(num_channels,
next_num_channels,
kernel_size=kernel_size,
stride=stride,
expand_rate=expand_rate,
se_rate=se_rate,
drop_connect_rate=drop_rate,
norm_cfg=norm_cfg,
act_cfg=act_cfg)))
counter += 1
for i in range(1, num_repeats):
name = 'MBConv{}_{}'.format(expand_rate, counter)
drop_rate = drop_connect_rate * counter / num_blocks
blocks.append((name,
MBConv(next_num_channels,
next_num_channels,
kernel_size=kernel_size,
stride=1,
expand_rate=expand_rate,
se_rate=se_rate,
drop_connect_rate=drop_rate,
norm_cfg=norm_cfg,
act_cfg=act_cfg)))
counter += 1
self.blocks = nn.Sequential(OrderedDict(blocks))
# Define head
self.head = nn.Sequential(
ConvModule(self.list_channels[-2],
self.list_channels[-1],
kernel_size=1,
bias=False,
norm_cfg=norm_cfg,
act_cfg=act_cfg), nn.AdaptiveAvgPool2d(1), Flatten(),
nn.Dropout(p=dropout_rate),
nn.Linear(self.list_channels[-1], self.n_classes))
if isinstance(pretrained, str):
load_checkpoint(self, pretrained)
elif pretrained is None:
self.apply(init_weights)
else:
raise TypeError('pretrained must be a str or None')
self.freeze_stages()
def _setup_repeats(self, num_repeats):
return int(math.ceil(self.depth_coefficient * num_repeats))
def _setup_channels(self, num_channels):
"""To ensure the new number of channels can be divided by divisor, for example 8."""
num_channels *= self.width_coefficient
new_num_channels = math.floor(num_channels / self.divisor +
0.5) * self.divisor
# To ensure the new number of channels are greater or equal to divisor
new_num_channels = max(self.divisor, new_num_channels)
# To avoid number of channels shrink too much
if new_num_channels < 0.9 * num_channels:
new_num_channels += self.divisor
return new_num_channels
def freeze_stages(self):
if self.frozen_stages >= 0:
self.stem.eval()
for param in self.stem.parameters():
param.requires_grad = False
idx = 0
for i in range(1, self.frozen_stages + 1):
for _ in range(self.list_num_repeats[i - 1]):
self.blocks[idx].eval()
for param in self.blocks[idx].parameters():
param.requires_grad = False
idx += 1
def forward(self, x):
f = self.stem(x)
f = self.blocks(f)
y = self.head(f)
return y
class MobileNetV2(BaseBackbone):
"""MobileNetV2 backbone.
Args:
widen_factor (float): Width multiplier, multiply number of
channels in each layer by this amount. Default: 1.0.
out_indices (None or Sequence[int]): Output from which stages.
Default: (7, ).
frozen_stages (int): Stages to be frozen (all param fixed).
Default: -1, which means not freezing any parameters.
conv_cfg (dict, optional): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
act_cfg (dict): Config dict for activation layer.
Default: dict(type='ReLU6').
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
"""
# Parameters to build layers. 4 parameters are needed to construct a
# layer, from left to right: expand_ratio, channel, num_blocks, stride.
arch_settings = [[1, 16, 1, 1], [6, 24, 2, 2], [6, 32, 3, 2],
[6, 64, 4, 2], [6, 96, 3, 1], [6, 160, 3, 2],
[6, 320, 1, 1]]
def __init__(self,
widen_factor=1.,
out_indices=(7, ),
frozen_stages=-1,
conv_cfg=None,
norm_cfg=dict(type='BN'),
act_cfg=dict(type='ReLU6'),
norm_eval=False,
with_cp=False,
init_cfg=[
dict(type='Kaiming', layer=['Conv2d']),
dict(type='Constant',
val=1,
layer=['_BatchNorm', 'GroupNorm'])
]):
super(MobileNetV2, self).__init__(init_cfg)
self.widen_factor = widen_factor
self.out_indices = out_indices
for index in out_indices:
if index not in range(0, 8):
raise ValueError('the item in out_indices must in '
f'range(0, 8). But received {index}')
if frozen_stages not in range(-1, 8):
raise ValueError('frozen_stages must be in range(-1, 8). '
f'But received {frozen_stages}')
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
self.in_channels = make_divisible(32 * widen_factor, 8)
self.conv1 = ConvModule(in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.layers = []
for i, layer_cfg in enumerate(self.arch_settings):
expand_ratio, channel, num_blocks, stride = layer_cfg
out_channels = make_divisible(channel * widen_factor, 8)
inverted_res_layer = self.make_layer(out_channels=out_channels,
num_blocks=num_blocks,
stride=stride,
expand_ratio=expand_ratio)
layer_name = f'layer{i + 1}'
self.add_module(layer_name, inverted_res_layer)
self.layers.append(layer_name)
if widen_factor > 1.0:
self.out_channel = int(1280 * widen_factor)
else:
self.out_channel = 1280
layer = ConvModule(in_channels=self.in_channels,
out_channels=self.out_channel,
kernel_size=1,
stride=1,
padding=0,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.add_module('conv2', layer)
self.layers.append('conv2')
def make_layer(self, out_channels, num_blocks, stride, expand_ratio):
"""Stack InvertedResidual blocks to build a layer for MobileNetV2.
Args:
out_channels (int): out_channels of block.
num_blocks (int): number of blocks.
stride (int): stride of the first block. Default: 1
expand_ratio (int): Expand the number of channels of the
hidden layer in InvertedResidual by this ratio. Default: 6.
"""
layers = []
for i in range(num_blocks):
if i >= 1:
stride = 1
layers.append(
InvertedResidual(self.in_channels,
out_channels,
stride,
expand_ratio=expand_ratio,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp))
self.in_channels = out_channels
return nn.Sequential(*layers)
def forward(self, x):
x = self.conv1(x)
outs = []
for i, layer_name in enumerate(self.layers):
layer = getattr(self, layer_name)
x = layer(x)
if i in self.out_indices:
outs.append(x)
if len(outs) == 1:
return outs[0]
else:
return tuple(outs)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
layer = getattr(self, f'layer{i}')
layer.eval()
for param in layer.parameters():
param.requires_grad = False
def train(self, mode=True):
super(MobileNetV2, self).train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
class UDFMobileNetV2(BaseBackbone):
"""User defined MobileNetV2 backbone.
Args:
widen_factor (float): Width multiplier, multiply number of
channels in each layer by this amount. Default: 1.0.
out_indices (None or Sequence[int]): Output from which stages.
Default: (7, ).
frozen_stages (int): Stages to be frozen (all param fixed).
Default: -1, which means not freezing any parameters.
conv_cfg (dict, optional): Config dict for convolution layer.
Default: None, which means using conv2d.
norm_cfg (dict): Config dict for normalization layer.
Default: dict(type='BN').
act_cfg (dict): Config dict for activation layer.
Default: dict(type='ReLU6').
norm_eval (bool): Whether to set norm layers to eval mode, namely,
freeze running stats (mean and var). Note: Effect on Batch Norm
and its variants only. Default: False.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed. Default: False.
"""
# Parameters to build layers. 4 parameters are needed to construct a
# layer, from left to right: expand_ratio, channel, num_blocks, stride.
def __init__(self,
arch_settings=None,
conv_cfg=None,
norm_cfg=dict(type='BN'),
act_cfg=dict(type='ReLU6'),
norm_eval=False,
with_cp=False):
super(UDFMobileNetV2, self).__init__()
if arch_settings is None:
arch_settings = [[1, 32, 1, 2], [1, 16, 1, 1], [6, 24, 2, 2],
[6, 32, 3, 2], [6, 64, 4, 2], [6, 96, 3, 1],
[6, 160, 3, 2], [6, 320, 1, 1], [1, 1280, 1, 1]]
widen_factor = 1.0
self.widen_factor = widen_factor
assert len(arch_settings) >= 6
first_layer_cfg = arch_settings[0]
assert first_layer_cfg[0] == 1
assert first_layer_cfg[2] == 1
assert first_layer_cfg[3] == 2
last_layer_cfg = arch_settings[-1]
assert last_layer_cfg[0] == 1
assert last_layer_cfg[2] == 1
assert last_layer_cfg[3] == 1
self.out_indices = (len(arch_settings) - 2, )
self.frozen_stages = -1
self.conv_cfg = conv_cfg
self.norm_cfg = norm_cfg
self.act_cfg = act_cfg
self.norm_eval = norm_eval
self.with_cp = with_cp
self.in_channels = make_divisible(first_layer_cfg[1] * widen_factor, 8)
self.conv1 = ConvModule(in_channels=3,
out_channels=self.in_channels,
kernel_size=3,
stride=2,
padding=1,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.layers = []
for i, layer_cfg in enumerate(arch_settings[1:-1]):
expand_ratio, channel, num_blocks, stride = layer_cfg
out_channels = make_divisible(channel * widen_factor, 8)
inverted_res_layer = self.make_layer(out_channels=out_channels,
num_blocks=num_blocks,
stride=stride,
expand_ratio=expand_ratio)
layer_name = f'layer{i + 1}'
self.add_module(layer_name, inverted_res_layer)
self.layers.append(layer_name)
self.out_channel = int(last_layer_cfg[1] * widen_factor)
layer = ConvModule(in_channels=self.in_channels,
out_channels=self.out_channel,
kernel_size=1,
stride=1,
padding=0,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg)
self.add_module('conv2', layer)
self.layers.append('conv2')
def make_layer(self, out_channels, num_blocks, stride, expand_ratio):
""" Stack InvertedResidual blocks to build a layer for MobileNetV2.
Args:
out_channels (int): out_channels of block.
num_blocks (int): number of blocks.
stride (int): stride of the first block. Default: 1
expand_ratio (int): Expand the number of channels of the
hidden layer in InvertedResidual by this ratio. Default: 6.
"""
layers = []
for i in range(num_blocks):
if i >= 1:
stride = 1
layers.append(
InvertedResidual(self.in_channels,
out_channels,
stride,
expand_ratio=expand_ratio,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
act_cfg=self.act_cfg,
with_cp=self.with_cp))
self.in_channels = out_channels
return nn.Sequential(*layers)
def init_weights(self, pretrained=None):
if isinstance(pretrained, str):
logger = logging.getLogger()
load_checkpoint(self, pretrained, strict=False, logger=logger)
elif pretrained is None:
for m in self.modules():
if isinstance(m, nn.Conv2d):
kaiming_init(m)
elif isinstance(m, (_BatchNorm, nn.GroupNorm)):
constant_init(m, 1)
else:
raise TypeError('pretrained must be a str or None')
def forward(self, x):
x = self.conv1(x)
outs = []
for i, layer_name in enumerate(self.layers):
layer = getattr(self, layer_name)
x = layer(x)
if i in self.out_indices:
#print('out:', x.shape)
outs.append(x)
if len(outs) == 1:
return outs[0]
else:
return tuple(outs)
def _freeze_stages(self):
if self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
layer = getattr(self, f'layer{i}')
layer.eval()
for param in layer.parameters():
param.requires_grad = False
def train(self, mode=True):
super(UDFMobileNetV2, self).train(mode)
self._freeze_stages()
if mode and self.norm_eval:
for m in self.modules():
if isinstance(m, _BatchNorm):
m.eval()
