def __init__(self, cfg, input_shape: ShapeSpec):
"""
The following attributes are parsed from config:
num_conv: the number of conv layers
conv_dim: the dimension of the conv layers
norm: normalization for the conv layers
"""
super().__init__(cfg, input_shape)
# fmt: off
num_classes = cfg.MODEL.ROI_HEADS.NUM_CLASSES
conv_dims = cfg.MODEL.ROI_MASK_HEAD.CONV_DIM
self.norm = cfg.MODEL.ROI_MASK_HEAD.NORM
num_conv = cfg.MODEL.ROI_MASK_HEAD.NUM_CONV
input_channels = input_shape.channels
cls_agnostic_mask = cfg.MODEL.ROI_MASK_HEAD.CLS_AGNOSTIC_MASK
# fmt: on
self.conv_norm_relus = []
for k in range(num_conv):
conv = Conv2d(
input_channels if k == 0 else conv_dims,
conv_dims,
kernel_size=3,
stride=1,
padding=1,
bias=not self.norm,
norm=get_norm(self.norm, conv_dims),
activation=F.relu,
)
self.add_module("mask_fcn{}".format(k + 1), conv)
self.conv_norm_relus.append(conv)
self.deconv = ConvTranspose2d(
conv_dims if num_conv > 0 else input_channels,
conv_dims,
kernel_size=2,
stride=2,
padding=0,
)
num_mask_classes = 1 if cls_agnostic_mask else num_classes
self.predictor = Conv2d(conv_dims,
num_mask_classes,
kernel_size=1,
stride=1,
padding=0)
for layer in self.conv_norm_relus + [self.deconv]:
weight_init.c2_msra_fill(layer)
# use normal distribution initialization for mask prediction layer
nn.init.normal_(self.predictor.weight, std=0.001)
if self.predictor.bias is not None:
nn.init.constant_(self.predictor.bias, 0)
def __init__(self, cfg, in_channels):
super(KeypointRCNNFeatureExtractor, self).__init__()
resolution = cfg.MODEL.ROI_KEYPOINT_HEAD.POOLER_RESOLUTION
scales = cfg.MODEL.ROI_KEYPOINT_HEAD.POOLER_SCALES
sampling_ratio = cfg.MODEL.ROI_KEYPOINT_HEAD.POOLER_SAMPLING_RATIO
pooler = Pooler(
output_size=(resolution, resolution),
scales=scales,
sampling_ratio=sampling_ratio,
)
self.pooler = pooler
input_features = in_channels
layers = cfg.MODEL.ROI_KEYPOINT_HEAD.CONV_LAYERS
next_feature = input_features
self.blocks = []
for layer_idx, layer_features in enumerate(layers, 1):
layer_name = "conv_fcn{}".format(layer_idx)
module = Conv2d(next_feature,
layer_features,
3,
stride=1,
padding=1)
nn.init.kaiming_normal_(module.weight,
mode="fan_out",
nonlinearity="relu")
nn.init.constant_(module.bias, 0)
self.add_module(layer_name, module)
next_feature = layer_features
self.blocks.append(layer_name)
self.out_channels = layer_features
def make_conv(in_channels,
out_channels,
kernel_size,
stride=1,
dilation=1):
conv = Conv2d(in_channels,
out_channels,
kernel_size=kernel_size,
stride=stride,
padding=dilation * (kernel_size - 1) // 2,
dilation=dilation,
bias=False if use_gn else True)
# Caffe2 implementation uses XavierFill, which in fact
# corresponds to kaiming_uniform_ in PyTorch
nn.init.kaiming_uniform_(conv.weight, a=1)
if not use_gn:
nn.init.constant_(conv.bias, 0)
module = [
conv,
]
if use_gn:
module.append(group_norm(out_channels))
if use_relu:
module.append(nn.ReLU(inplace=True))
if len(module) > 1:
return nn.Sequential(*module)
return conv
def make_conv3x3(in_channels,
out_channels,
dilation=1,
stride=1,
use_gn=False,
use_relu=False,
kaiming_init=True):
conv = Conv2d(in_channels,
out_channels,
kernel_size=3,
stride=stride,
padding=dilation,
dilation=dilation,
bias=False if use_gn else True)
if kaiming_init:
nn.init.kaiming_normal_(conv.weight,
mode="fan_out",
nonlinearity="relu")
else:
torch.nn.init.normal_(conv.weight, std=0.01)
if not use_gn:
nn.init.constant_(conv.bias, 0)
module = [
conv,
]
if use_gn:
module.append(group_norm(out_channels))
if use_relu:
module.append(nn.ReLU(inplace=True))
if len(module) > 1:
return nn.Sequential(*module)
return conv
def __init__(self, cfg, input_shape: Dict[str, ShapeSpec]):
super().__init__()
# fmt: off
self.in_features = cfg.MODEL.SEM_SEG_HEAD.IN_FEATURES
feature_strides = {k: v.stride for k, v in input_shape.items()}
feature_channels = {k: v.channels for k, v in input_shape.items()}
self.ignore_value = cfg.MODEL.SEM_SEG_HEAD.IGNORE_VALUE
num_classes = cfg.MODEL.SEM_SEG_HEAD.NUM_CLASSES
conv_dims = cfg.MODEL.SEM_SEG_HEAD.CONVS_DIM
self.common_stride = cfg.MODEL.SEM_SEG_HEAD.COMMON_STRIDE
norm = cfg.MODEL.SEM_SEG_HEAD.NORM
self.loss_weight = cfg.MODEL.SEM_SEG_HEAD.LOSS_WEIGHT
# fmt: on
self.scale_heads = []
for in_feature in self.in_features:
head_ops = []
head_length = max(
1, int(np.log2(feature_strides[in_feature]) - np.log2(self.common_stride))
)
for k in range(head_length):
norm_module = nn.GroupNorm(32, conv_dims) if norm == "GN" else None
conv = Conv2d(
feature_channels[in_feature] if k == 0 else conv_dims,
conv_dims,
kernel_size=3,
stride=1,
padding=1,
bias=not norm,
norm=norm_module,
activation=F.relu,
)
weight_init.c2_msra_fill(conv)
head_ops.append(conv)
if feature_strides[in_feature] != self.common_stride:
head_ops.append(
nn.Upsample(scale_factor=2, mode="bilinear", align_corners=False)
)
self.scale_heads.append(nn.Sequential(*head_ops))
self.add_module(in_feature, self.scale_heads[-1])
self.predictor = Conv2d(conv_dims, num_classes, kernel_size=1, stride=1, padding=0)
weight_init.c2_msra_fill(self.predictor)
def __init__(self, cfg, input_shape: Dict[str, ShapeSpec], in_features):
super(Decoder, self).__init__()
# fmt: off
self.in_features = in_features
feature_strides = {k: v.stride for k, v in input_shape.items()}
feature_channels = {k: v.channels for k, v in input_shape.items()}
num_classes = cfg.MODEL.ROI_DENSEPOSE_HEAD.DECODER_NUM_CLASSES
conv_dims = cfg.MODEL.ROI_DENSEPOSE_HEAD.DECODER_CONV_DIMS
self.common_stride = cfg.MODEL.ROI_DENSEPOSE_HEAD.DECODER_COMMON_STRIDE
norm = cfg.MODEL.ROI_DENSEPOSE_HEAD.DECODER_NORM
# fmt: on
self.scale_heads = []
for in_feature in self.in_features:
head_ops = []
head_length = max(
1, int(np.log2(feature_strides[in_feature]) - np.log2(self.common_stride))
)
for k in range(head_length):
conv = Conv2d(
feature_channels[in_feature] if k == 0 else conv_dims,
conv_dims,
kernel_size=3,
stride=1,
padding=1,
bias=not norm,
norm=get_norm(norm, conv_dims),
activation=F.relu,
)
weight_init.c2_msra_fill(conv)
head_ops.append(conv)
if feature_strides[in_feature] != self.common_stride:
head_ops.append(
nn.Upsample(scale_factor=2, mode="bilinear", align_corners=False)
)
self.scale_heads.append(nn.Sequential(*head_ops))
self.add_module(in_feature, self.scale_heads[-1])
self.predictor = Conv2d(conv_dims, num_classes, kernel_size=1, stride=1, padding=0)
weight_init.c2_msra_fill(self.predictor)
def __init__(self, cfg, in_channels):
super(MaskRCNNConv1x1Predictor, self).__init__()
num_classes = cfg.MODEL.ROI_BOX_HEAD.NUM_CLASSES
num_inputs = in_channels
self.mask_fcn_logits = Conv2d(num_inputs, num_classes, 1, 1, 0)
for name, param in self.named_parameters():
if "bias" in name:
nn.init.constant_(param, 0)
elif "weight" in name:
# Caffe2 implementation uses MSRAFill, which in fact
# corresponds to kaiming_normal_ in PyTorch
nn.init.kaiming_normal_(param, mode="fan_out", nonlinearity="relu")
def __init__(self, cfg, norm_func):
super(BaseStem, self).__init__()
out_channels = cfg.MODEL.RESNETS.STEM_OUT_CHANNELS
self.conv1 = Conv2d(3,
out_channels,
kernel_size=7,
stride=2,
padding=3,
bias=False)
self.bn1 = norm_func(out_channels)
for l in [
self.conv1,
]:
nn.init.kaiming_uniform_(l.weight, a=1)
def __init__(self, cfg, input_shape: ShapeSpec):
"""
The following attributes are parsed from config:
conv_dims: an iterable of output channel counts for each conv in the head
e.g. (512, 512, 512) for three convs outputting 512 channels.
num_keypoints: number of keypoint heatmaps to predicts, determines the number of
channels in the final output.
"""
super().__init__(cfg, input_shape)
# fmt: off
# default up_scale to 2 (this can eventually be moved to config)
up_scale = 2
conv_dims = cfg.MODEL.ROI_KEYPOINT_HEAD.CONV_DIMS
num_keypoints = cfg.MODEL.ROI_KEYPOINT_HEAD.NUM_KEYPOINTS
in_channels = input_shape.channels
# fmt: on
self.blocks = []
for idx, layer_channels in enumerate(conv_dims, 1):
module = Conv2d(in_channels,
layer_channels,
3,
stride=1,
padding=1)
self.add_module("conv_fcn{}".format(idx), module)
self.blocks.append(module)
in_channels = layer_channels
deconv_kernel = 4
self.score_lowres = ConvTranspose2d(in_channels,
num_keypoints,
deconv_kernel,
stride=2,
padding=deconv_kernel // 2 - 1)
self.up_scale = up_scale
for name, param in self.named_parameters():
if "bias" in name:
nn.init.constant_(param, 0)
elif "weight" in name:
# Caffe2 implementation uses MSRAFill, which in fact
# corresponds to kaiming_normal_ in PyTorch
nn.init.kaiming_normal_(param,
mode="fan_out",
nonlinearity="relu")
def __init__(self, cfg, input_shape: ShapeSpec):
"""
The following attributes are parsed from config:
num_conv, num_fc: the number of conv/fc layers
conv_dim/fc_dim: the dimension of the conv/fc layers
norm: normalization for the conv layers
"""
super().__init__()
# fmt: off
num_conv = cfg.MODEL.ROI_BOX_HEAD.NUM_CONV
conv_dim = cfg.MODEL.ROI_BOX_HEAD.CONV_DIM
num_fc = cfg.MODEL.ROI_BOX_HEAD.NUM_FC
fc_dim = cfg.MODEL.ROI_BOX_HEAD.FC_DIM
norm = cfg.MODEL.ROI_BOX_HEAD.NORM
# fmt: on
assert num_conv + num_fc > 0
self._output_size = (input_shape.channels, input_shape.height, input_shape.width)
self.conv_norm_relus = []
for k in range(num_conv):
conv = Conv2d(
self._output_size[0],
conv_dim,
kernel_size=3,
padding=1,
bias=not norm,
norm=get_norm(norm, conv_dim),
activation=F.relu,
)
self.add_module("conv{}".format(k + 1), conv)
self.conv_norm_relus.append(conv)
self._output_size = (conv_dim, self._output_size[1], self._output_size[2])
self.fcs = []
for k in range(num_fc):
fc = Linear(np.prod(self._output_size), fc_dim)
self.add_module("fc{}".format(k + 1), fc)
self.fcs.append(fc)
self._output_size = fc_dim
for layer in self.conv_norm_relus:
weight_init.c2_msra_fill(layer)
for layer in self.fcs:
weight_init.c2_xavier_fill(layer)
def __init__(self, in_channels=3, out_channels=64, norm="BN"):
"""
Args:
norm (str or callable): a callable that takes the number of
channels and return a `nn.Module`, or a pre-defined string
(one of {"FrozenBN", "BN", "GN"}).
"""
super().__init__()
self.conv1 = Conv2d(
in_channels,
out_channels,
kernel_size=7,
stride=2,
padding=3,
bias=False,
norm=get_norm(norm, out_channels),
)
weight_init.c2_msra_fill(self.conv1)
def __init__(self, cfg, input_channels):
super(DensePoseV1ConvXHead, self).__init__()
# fmt: off
hidden_dim = cfg.MODEL.ROI_DENSEPOSE_HEAD.CONV_HEAD_DIM
kernel_size = cfg.MODEL.ROI_DENSEPOSE_HEAD.CONV_HEAD_KERNEL
self.n_stacked_convs = cfg.MODEL.ROI_DENSEPOSE_HEAD.NUM_STACKED_CONVS
# fmt: on
pad_size = kernel_size // 2
n_channels = input_channels
for i in range(self.n_stacked_convs):
layer = Conv2d(n_channels,
hidden_dim,
kernel_size,
stride=1,
padding=pad_size)
layer_name = self._get_layer_name(i)
self.add_module(layer_name, layer)
n_channels = hidden_dim
self.n_out_channels = n_channels
initialize_module_params(self)
def __init__(self, cfg, input_channels):
super(DensePoseDeepLabHead, self).__init__()
# fmt: off
hidden_dim = cfg.MODEL.ROI_DENSEPOSE_HEAD.CONV_HEAD_DIM
kernel_size = cfg.MODEL.ROI_DENSEPOSE_HEAD.CONV_HEAD_KERNEL
norm = cfg.MODEL.ROI_DENSEPOSE_HEAD.DEEPLAB.NORM
self.n_stacked_convs = cfg.MODEL.ROI_DENSEPOSE_HEAD.NUM_STACKED_CONVS
self.use_nonlocal = cfg.MODEL.ROI_DENSEPOSE_HEAD.DEEPLAB.NONLOCAL_ON
# fmt: on
pad_size = kernel_size // 2
n_channels = input_channels
self.ASPP = ASPP(input_channels, [6, 12, 56], n_channels) # 6, 12, 56
self.add_module("ASPP", self.ASPP)
if self.use_nonlocal:
self.NLBlock = NONLocalBlock2D(input_channels, bn_layer=True)
self.add_module("NLBlock", self.NLBlock)
# weight_init.c2_msra_fill(self.ASPP)
for i in range(self.n_stacked_convs):
norm_module = nn.GroupNorm(32,
hidden_dim) if norm == "GN" else None
layer = Conv2d(
n_channels,
hidden_dim,
kernel_size,
stride=1,
padding=pad_size,
bias=not norm,
norm=norm_module,
)
weight_init.c2_msra_fill(layer)
n_channels = hidden_dim
layer_name = self._get_layer_name(i)
self.add_module(layer_name, layer)
self.n_out_channels = hidden_dim
def __init__(self, in_channels, bottleneck_channels, out_channels,
num_groups, stride_in_1x1, stride, dilation, norm_func,
dcn_config):
super(Bottleneck, self).__init__()
self.downsample = None
if in_channels != out_channels:
down_stride = stride if dilation == 1 else 1
self.downsample = nn.Sequential(
Conv2d(in_channels,
out_channels,
kernel_size=1,
stride=down_stride,
bias=False),
norm_func(out_channels),
)
for modules in [
self.downsample,
]:
for l in modules.modules():
if isinstance(l, Conv2d):
nn.init.kaiming_uniform_(l.weight, a=1)
if dilation > 1:
stride = 1 # reset to be 1
# The original MSRA ResNet models have stride in the first 1x1 conv
# The subsequent fb.torch.resnet and Caffe2 ResNe[X]t implementations have
# stride in the 3x3 conv
stride_1x1, stride_3x3 = (stride, 1) if stride_in_1x1 else (1, stride)
self.conv1 = Conv2d(
in_channels,
bottleneck_channels,
kernel_size=1,
stride=stride_1x1,
bias=False,
)
self.bn1 = norm_func(bottleneck_channels)
# TODO: specify init for the above
with_dcn = dcn_config.get("stage_with_dcn", False)
if with_dcn:
deformable_groups = dcn_config.get("deformable_groups", 1)
with_modulated_dcn = dcn_config.get("with_modulated_dcn", False)
self.conv2 = DFConv2d(bottleneck_channels,
bottleneck_channels,
with_modulated_dcn=with_modulated_dcn,
kernel_size=3,
stride=stride_3x3,
groups=num_groups,
dilation=dilation,
deformable_groups=deformable_groups,
bias=False)
else:
self.conv2 = Conv2d(bottleneck_channels,
bottleneck_channels,
kernel_size=3,
stride=stride_3x3,
padding=dilation,
bias=False,
groups=num_groups,
dilation=dilation)
nn.init.kaiming_uniform_(self.conv2.weight, a=1)
self.bn2 = norm_func(bottleneck_channels)
self.conv3 = Conv2d(bottleneck_channels,
out_channels,
kernel_size=1,
bias=False)
self.bn3 = norm_func(out_channels)
for l in [
self.conv1,
self.conv3,
]:
nn.init.kaiming_uniform_(l.weight, a=1)
def __init__(self, cfg, input_shape: ShapeSpec):
"""
The following attributes are parsed from config:
conv_dim: the output dimension of the conv layers
fc_dim: the feature dimenstion of the FC layers
num_fc: the number of FC layers
output_side_resolution: side resolution of the output square mask prediction
"""
super(CoarseMaskHead, self).__init__()
# fmt: off
self.num_classes = cfg.MODEL.ROI_HEADS.NUM_CLASSES
conv_dim = cfg.MODEL.ROI_MASK_HEAD.CONV_DIM
self.fc_dim = cfg.MODEL.ROI_MASK_HEAD.FC_DIM
num_fc = cfg.MODEL.ROI_MASK_HEAD.NUM_FC
self.output_side_resolution = cfg.MODEL.ROI_MASK_HEAD.OUTPUT_SIDE_RESOLUTION
self.input_channels = input_shape.channels
self.input_h = input_shape.height
self.input_w = input_shape.width
# fmt: on
self.conv_layers = []
if self.input_channels > conv_dim:
self.reduce_channel_dim_conv = Conv2d(
self.input_channels,
conv_dim,
kernel_size=1,
stride=1,
padding=0,
bias=True,
activation=F.relu,
)
self.conv_layers.append(self.reduce_channel_dim_conv)
self.reduce_spatial_dim_conv = Conv2d(conv_dim,
conv_dim,
kernel_size=2,
stride=2,
padding=0,
bias=True,
activation=F.relu)
self.conv_layers.append(self.reduce_spatial_dim_conv)
input_dim = conv_dim * self.input_h * self.input_w
input_dim //= 4
self.fcs = []
for k in range(num_fc):
fc = nn.Linear(input_dim, self.fc_dim)
self.add_module("coarse_mask_fc{}".format(k + 1), fc)
self.fcs.append(fc)
input_dim = self.fc_dim
output_dim = self.num_classes * self.output_side_resolution * self.output_side_resolution
self.prediction = nn.Linear(self.fc_dim, output_dim)
# use normal distribution initialization for mask prediction layer
nn.init.normal_(self.prediction.weight, std=0.001)
nn.init.constant_(self.prediction.bias, 0)
for layer in self.conv_layers:
weight_init.c2_msra_fill(layer)
for layer in self.fcs:
weight_init.c2_xavier_fill(layer)
def __init__(
self,
in_channels,
out_channels,
*,
bottleneck_channels,
stride=1,
num_groups=1,
norm="BN",
stride_in_1x1=False,
num_branch=3,
dilations=(1, 2, 3),
concat_output=False,
test_branch_idx=-1,
):
"""
Args:
num_branch (int): the number of branches in TridentNet.
dilations (tuple): the dilations of multiple branches in TridentNet.
concat_output (bool): if concatenate outputs of multiple branches in TridentNet.
Use 'True' for the last trident block.
"""
super().__init__(in_channels, out_channels, stride)
assert num_branch == len(dilations)
self.num_branch = num_branch
self.concat_output = concat_output
self.test_branch_idx = test_branch_idx
if in_channels != out_channels:
self.shortcut = Conv2d(
in_channels,
out_channels,
kernel_size=1,
stride=stride,
bias=False,
norm=get_norm(norm, out_channels),
)
else:
self.shortcut = None
stride_1x1, stride_3x3 = (stride, 1) if stride_in_1x1 else (1, stride)
self.conv1 = Conv2d(
in_channels,
bottleneck_channels,
kernel_size=1,
stride=stride_1x1,
bias=False,
norm=get_norm(norm, bottleneck_channels),
)
self.conv2 = TridentConv(
bottleneck_channels,
bottleneck_channels,
kernel_size=3,
stride=stride_3x3,
paddings=dilations,
bias=False,
groups=num_groups,
dilations=dilations,
num_branch=num_branch,
test_branch_idx=test_branch_idx,
norm=get_norm(norm, bottleneck_channels),
)
self.conv3 = Conv2d(
bottleneck_channels,
out_channels,
kernel_size=1,
bias=False,
norm=get_norm(norm, out_channels),
)
for layer in [self.conv1, self.conv2, self.conv3, self.shortcut]:
if layer is not None: # shortcut can be None
weight_init.c2_msra_fill(layer)
def __init__(
self,
in_channels,
out_channels,
*,
bottleneck_channels,
stride=1,
num_groups=1,
norm="BN",
stride_in_1x1=False,
dilation=1,
):
"""
Args:
norm (str or callable): a callable that takes the number of
channels and return a `nn.Module`, or a pre-defined string
(one of {"FrozenBN", "BN", "GN"}).
stride_in_1x1 (bool): when stride==2, whether to put stride in the
first 1x1 convolution or the bottleneck 3x3 convolution.
"""
super().__init__(in_channels, out_channels, stride)
if in_channels != out_channels:
self.shortcut = Conv2d(
in_channels,
out_channels,
kernel_size=1,
stride=stride,
bias=False,
norm=get_norm(norm, out_channels),
)
else:
self.shortcut = None
# The original MSRA ResNet models have stride in the first 1x1 conv
# The subsequent fb.torch.resnet and Caffe2 ResNe[X]t implementations have
# stride in the 3x3 conv
stride_1x1, stride_3x3 = (stride, 1) if stride_in_1x1 else (1, stride)
self.conv1 = Conv2d(
in_channels,
bottleneck_channels,
kernel_size=1,
stride=stride_1x1,
bias=False,
norm=get_norm(norm, bottleneck_channels),
)
self.conv2 = Conv2d(
bottleneck_channels,
bottleneck_channels,
kernel_size=3,
stride=stride_3x3,
padding=1 * dilation,
bias=False,
groups=num_groups,
dilation=dilation,
norm=get_norm(norm, bottleneck_channels),
)
self.conv3 = Conv2d(
bottleneck_channels,
out_channels,
kernel_size=1,
bias=False,
norm=get_norm(norm, out_channels),
)
for layer in [self.conv1, self.conv2, self.conv3, self.shortcut]:
if layer is not None: # shortcut can be None
weight_init.c2_msra_fill(layer)
def __init__(
self, bottom_up, in_features, out_channels, norm="", top_block=None, fuse_type="sum"
):
"""
Args:
bottom_up (Backbone): module representing the bottom up subnetwork.
Must be a subclass of :class:`Backbone`. The multi-scale feature
maps generated by the bottom up network, and listed in `in_features`,
are used to generate FPN levels.
in_features (list[str]): names of the input feature maps coming
from the backbone to which FPN is attached. For example, if the
backbone produces ["res2", "res3", "res4"], any *contiguous* sublist
of these may be used; order must be from high to low resolution.
out_channels (int): number of channels in the output feature maps.
norm (str): the normalization to use.
top_block (nn.Module or None): if provided, an extra operation will
be performed on the output of the last (smallest resolution)
FPN output, and the result will extend the result list. The top_block
further downsamples the feature map. It must have an attribute
"num_levels", meaning the number of extra FPN levels added by
this block, and "in_feature", which is a string representing
its input feature (e.g., p5).
fuse_type (str): types for fusing the top down features and the lateral
ones. It can be "sum" (default), which sums up element-wise; or "avg",
which takes the element-wise mean of the two.
"""
super(FPN, self).__init__()
assert isinstance(bottom_up, Backbone)
# Feature map strides and channels from the bottom up network (e.g. ResNet)
input_shapes = bottom_up.output_shape()
in_strides = [input_shapes[f].stride for f in in_features]
in_channels = [input_shapes[f].channels for f in in_features]
_assert_strides_are_log2_contiguous(in_strides)
lateral_convs = []
output_convs = []
use_bias = norm == ""
for idx, in_channels in enumerate(in_channels):
lateral_norm = get_norm(norm, out_channels)
output_norm = get_norm(norm, out_channels)
lateral_conv = Conv2d(
in_channels, out_channels, kernel_size=1, bias=use_bias, norm=lateral_norm
)
output_conv = Conv2d(
out_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1,
bias=use_bias,
norm=output_norm,
)
weight_init.c2_xavier_fill(lateral_conv)
weight_init.c2_xavier_fill(output_conv)
stage = int(math.log2(in_strides[idx]))
self.add_module("fpn_lateral{}".format(stage), lateral_conv)
self.add_module("fpn_output{}".format(stage), output_conv)
lateral_convs.append(lateral_conv)
output_convs.append(output_conv)
# Place convs into top-down order (from low to high resolution)
# to make the top-down computation in forward clearer.
self.lateral_convs = lateral_convs[::-1]
self.output_convs = output_convs[::-1]
self.top_block = top_block
self.in_features = in_features
self.bottom_up = bottom_up
# Return feature names are "p<stage>", like ["p2", "p3", ..., "p6"]
self._out_feature_strides = {"p{}".format(int(math.log2(s))): s for s in in_strides}
# top block output feature maps.
if self.top_block is not None:
for s in range(stage, stage + self.top_block.num_levels):
self._out_feature_strides["p{}".format(s + 1)] = 2 ** (s + 1)
self._out_features = list(self._out_feature_strides.keys())
self._out_feature_channels = {k: out_channels for k in self._out_features}
self._size_divisibility = in_strides[-1]
assert fuse_type in {"avg", "sum"}
self._fuse_type = fuse_type
def __init__(
self,
in_channels,
out_channels,
*,
bottleneck_channels,
stride=1,
num_groups=1,
norm="BN",
stride_in_1x1=False,
dilation=1,
deform_modulated=False,
deform_num_groups=1,
):
"""
Similar to :class:`BottleneckBlock`, but with deformable conv in the 3x3 convolution.
"""
super().__init__(in_channels, out_channels, stride)
self.deform_modulated = deform_modulated
if in_channels != out_channels:
self.shortcut = Conv2d(
in_channels,
out_channels,
kernel_size=1,
stride=stride,
bias=False,
norm=get_norm(norm, out_channels),
)
else:
self.shortcut = None
stride_1x1, stride_3x3 = (stride, 1) if stride_in_1x1 else (1, stride)
self.conv1 = Conv2d(
in_channels,
bottleneck_channels,
kernel_size=1,
stride=stride_1x1,
bias=False,
norm=get_norm(norm, bottleneck_channels),
)
if deform_modulated:
deform_conv_op = ModulatedDeformConv
# offset channels are 2 or 3 (if with modulated) * kernel_size * kernel_size
offset_channels = 27
else:
deform_conv_op = DeformConv
offset_channels = 18
self.conv2_offset = Conv2d(
bottleneck_channels,
offset_channels * deform_num_groups,
kernel_size=3,
stride=stride_3x3,
padding=1 * dilation,
dilation=dilation,
)
self.conv2 = deform_conv_op(
bottleneck_channels,
bottleneck_channels,
kernel_size=3,
stride=stride_3x3,
padding=1 * dilation,
bias=False,
groups=num_groups,
dilation=dilation,
deformable_groups=deform_num_groups,
norm=get_norm(norm, bottleneck_channels),
)
self.conv3 = Conv2d(
bottleneck_channels,
out_channels,
kernel_size=1,
bias=False,
norm=get_norm(norm, out_channels),
)
for layer in [self.conv1, self.conv2, self.conv3, self.shortcut]:
if layer is not None: # shortcut can be None
weight_init.c2_msra_fill(layer)
nn.init.constant_(self.conv2_offset.weight, 0)
nn.init.constant_(self.conv2_offset.bias, 0)