Spaces:
Runtime error
Runtime error
File size: 10,863 Bytes
b334e29 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 |
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.utils.checkpoint as cp
from mmcv.cnn import build_conv_layer, build_norm_layer, kaiming_init
from torch.nn.modules.utils import _pair
from mmdet.models.backbones.resnet import Bottleneck, ResNet
from mmdet.models.builder import BACKBONES
class TridentConv(nn.Module):
"""Trident Convolution Module.
Args:
in_channels (int): Number of channels in input.
out_channels (int): Number of channels in output.
kernel_size (int): Size of convolution kernel.
stride (int, optional): Convolution stride. Default: 1.
trident_dilations (tuple[int, int, int], optional): Dilations of
different trident branch. Default: (1, 2, 3).
test_branch_idx (int, optional): In inference, all 3 branches will
be used if `test_branch_idx==-1`, otherwise only branch with
index `test_branch_idx` will be used. Default: 1.
bias (bool, optional): Whether to use bias in convolution or not.
Default: False.
"""
def __init__(self,
in_channels,
out_channels,
kernel_size,
stride=1,
trident_dilations=(1, 2, 3),
test_branch_idx=1,
bias=False):
super(TridentConv, self).__init__()
self.num_branch = len(trident_dilations)
self.with_bias = bias
self.test_branch_idx = test_branch_idx
self.stride = _pair(stride)
self.kernel_size = _pair(kernel_size)
self.paddings = _pair(trident_dilations)
self.dilations = trident_dilations
self.in_channels = in_channels
self.out_channels = out_channels
self.bias = bias
self.weight = nn.Parameter(
torch.Tensor(out_channels, in_channels, *self.kernel_size))
if bias:
self.bias = nn.Parameter(torch.Tensor(out_channels))
else:
self.bias = None
self.init_weights()
def init_weights(self):
kaiming_init(self, distribution='uniform', mode='fan_in')
def extra_repr(self):
tmpstr = f'in_channels={self.in_channels}'
tmpstr += f', out_channels={self.out_channels}'
tmpstr += f', kernel_size={self.kernel_size}'
tmpstr += f', num_branch={self.num_branch}'
tmpstr += f', test_branch_idx={self.test_branch_idx}'
tmpstr += f', stride={self.stride}'
tmpstr += f', paddings={self.paddings}'
tmpstr += f', dilations={self.dilations}'
tmpstr += f', bias={self.bias}'
return tmpstr
def forward(self, inputs):
if self.training or self.test_branch_idx == -1:
outputs = [
F.conv2d(input, self.weight, self.bias, self.stride, padding,
dilation) for input, dilation, padding in zip(
inputs, self.dilations, self.paddings)
]
else:
assert len(inputs) == 1
outputs = [
F.conv2d(inputs[0], self.weight, self.bias, self.stride,
self.paddings[self.test_branch_idx],
self.dilations[self.test_branch_idx])
]
return outputs
# Since TridentNet is defined over ResNet50 and ResNet101, here we
# only support TridentBottleneckBlock.
class TridentBottleneck(Bottleneck):
"""BottleBlock for TridentResNet.
Args:
trident_dilations (tuple[int, int, int]): Dilations of different
trident branch.
test_branch_idx (int): In inference, all 3 branches will be used
if `test_branch_idx==-1`, otherwise only branch with index
`test_branch_idx` will be used.
concat_output (bool): Whether to concat the output list to a Tensor.
`True` only in the last Block.
"""
def __init__(self, trident_dilations, test_branch_idx, concat_output,
**kwargs):
super(TridentBottleneck, self).__init__(**kwargs)
self.trident_dilations = trident_dilations
self.num_branch = len(trident_dilations)
self.concat_output = concat_output
self.test_branch_idx = test_branch_idx
self.conv2 = TridentConv(
self.planes,
self.planes,
kernel_size=3,
stride=self.conv2_stride,
bias=False,
trident_dilations=self.trident_dilations,
test_branch_idx=test_branch_idx)
def forward(self, x):
def _inner_forward(x):
num_branch = (
self.num_branch
if self.training or self.test_branch_idx == -1 else 1)
identity = x
if not isinstance(x, list):
x = (x, ) * num_branch
identity = x
if self.downsample is not None:
identity = [self.downsample(b) for b in x]
out = [self.conv1(b) for b in x]
out = [self.norm1(b) for b in out]
out = [self.relu(b) for b in out]
if self.with_plugins:
for k in range(len(out)):
out[k] = self.forward_plugin(out[k],
self.after_conv1_plugin_names)
out = self.conv2(out)
out = [self.norm2(b) for b in out]
out = [self.relu(b) for b in out]
if self.with_plugins:
for k in range(len(out)):
out[k] = self.forward_plugin(out[k],
self.after_conv2_plugin_names)
out = [self.conv3(b) for b in out]
out = [self.norm3(b) for b in out]
if self.with_plugins:
for k in range(len(out)):
out[k] = self.forward_plugin(out[k],
self.after_conv3_plugin_names)
out = [
out_b + identity_b for out_b, identity_b in zip(out, identity)
]
return out
if self.with_cp and x.requires_grad:
out = cp.checkpoint(_inner_forward, x)
else:
out = _inner_forward(x)
out = [self.relu(b) for b in out]
if self.concat_output:
out = torch.cat(out, dim=0)
return out
def make_trident_res_layer(block,
inplanes,
planes,
num_blocks,
stride=1,
trident_dilations=(1, 2, 3),
style='pytorch',
with_cp=False,
conv_cfg=None,
norm_cfg=dict(type='BN'),
dcn=None,
plugins=None,
test_branch_idx=-1):
"""Build Trident Res Layers."""
downsample = None
if stride != 1 or inplanes != planes * block.expansion:
downsample = []
conv_stride = stride
downsample.extend([
build_conv_layer(
conv_cfg,
inplanes,
planes * block.expansion,
kernel_size=1,
stride=conv_stride,
bias=False),
build_norm_layer(norm_cfg, planes * block.expansion)[1]
])
downsample = nn.Sequential(*downsample)
layers = []
for i in range(num_blocks):
layers.append(
block(
inplanes=inplanes,
planes=planes,
stride=stride if i == 0 else 1,
trident_dilations=trident_dilations,
downsample=downsample if i == 0 else None,
style=style,
with_cp=with_cp,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
dcn=dcn,
plugins=plugins,
test_branch_idx=test_branch_idx,
concat_output=True if i == num_blocks - 1 else False))
inplanes = planes * block.expansion
return nn.Sequential(*layers)
@BACKBONES.register_module()
class TridentResNet(ResNet):
"""The stem layer, stage 1 and stage 2 in Trident ResNet are identical to
ResNet, while in stage 3, Trident BottleBlock is utilized to replace the
normal BottleBlock to yield trident output. Different branch shares the
convolution weight but uses different dilations to achieve multi-scale
output.
/ stage3(b0) \
x - stem - stage1 - stage2 - stage3(b1) - output
\ stage3(b2) /
Args:
depth (int): Depth of resnet, from {50, 101, 152}.
num_branch (int): Number of branches in TridentNet.
test_branch_idx (int): In inference, all 3 branches will be used
if `test_branch_idx==-1`, otherwise only branch with index
`test_branch_idx` will be used.
trident_dilations (tuple[int]): Dilations of different trident branch.
len(trident_dilations) should be equal to num_branch.
""" # noqa
def __init__(self, depth, num_branch, test_branch_idx, trident_dilations,
**kwargs):
assert num_branch == len(trident_dilations)
assert depth in (50, 101, 152)
super(TridentResNet, self).__init__(depth, **kwargs)
assert self.num_stages == 3
self.test_branch_idx = test_branch_idx
self.num_branch = num_branch
last_stage_idx = self.num_stages - 1
stride = self.strides[last_stage_idx]
dilation = trident_dilations
dcn = self.dcn if self.stage_with_dcn[last_stage_idx] else None
if self.plugins is not None:
stage_plugins = self.make_stage_plugins(self.plugins,
last_stage_idx)
else:
stage_plugins = None
planes = self.base_channels * 2**last_stage_idx
res_layer = make_trident_res_layer(
TridentBottleneck,
inplanes=(self.block.expansion * self.base_channels *
2**(last_stage_idx - 1)),
planes=planes,
num_blocks=self.stage_blocks[last_stage_idx],
stride=stride,
trident_dilations=dilation,
style=self.style,
with_cp=self.with_cp,
conv_cfg=self.conv_cfg,
norm_cfg=self.norm_cfg,
dcn=dcn,
plugins=stage_plugins,
test_branch_idx=self.test_branch_idx)
layer_name = f'layer{last_stage_idx + 1}'
self.__setattr__(layer_name, res_layer)
self.res_layers.pop(last_stage_idx)
self.res_layers.insert(last_stage_idx, layer_name)
self._freeze_stages()
|