add shufflenet_v1

pull/2/head
louzan 2020-05-28 11:44:43 +08:00
parent 6515bb999c
commit a542651794
1 changed files with 311 additions and 0 deletions

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import logging
from collections import OrderedDict
import torch
import torch.nn as nn
import torch.utils.checkpoint as cp
from ..runner import load_checkpoint
from .base_backbone import BaseBackbone
from .weight_init import constant_init, kaiming_init
def conv3x3(inplanes, planes, stride=1, padding=1, bias=False, groups=1):
"""3x3 convolution with padding
"""
return nn.Conv2d(
inplanes,
planes,
kernel_size=3,
stride=stride,
padding=padding,
bias=bias,
groups=groups)
def conv1x1(inplanes, planes, groups=1):
"""1x1 convolution with padding
- Normal pointwise convolution when groups == 1
- Grouped pointwise convolution when groups > 1
"""
return nn.Conv2d(
inplanes,
planes,
kernel_size=1,
groups=groups,
stride=1)
def channel_shuffle(x, groups):
batchsize, num_channels, height, width = x.data.size()
assert (num_channels % groups == 0)
channels_per_group = num_channels // groups
# reshape
x = x.view(batchsize, groups, channels_per_group, height, width)
# transpose
# - contiguous() required if transpose() is used before view().
# See https://github.com/pytorch/pytorch/issues/764
x = torch.transpose(x, 1, 2).contiguous()
# flatten
x = x.view(batchsize, -1, height, width)
return x
def _make_divisible(v, divisor, min_value=None):
if min_value is None:
min_value = divisor
new_v = max(min_value, int(v + divisor / 2) // divisor * divisor)
# Make sure that round down does not go down by more than 10%.
if new_v < 0.9 * v:
new_v += divisor
return new_v
# noinspection PyShadowingNames,PyShadowingNames
class ShuffleUnit(nn.Module):
def __init__(self,
inplanes,
planes,
groups=3,
first_block=True,
combine='add',
with_cp=False):
super(ShuffleUnit, self).__init__()
self.inplanes = inplanes
self.planes = planes
self.first_block = first_block
self.combine = combine
self.groups = groups
self.bottleneck_channels = self.planes // 4
self.with_cp = with_cp
if self.combine == 'add':
self.depthwise_stride = 1
self._combine_func = self._add
elif self.combine == 'concat':
self.depthwise_stride = 2
self._combine_func = self._concat
self.planes -= self.inplanes
else:
raise ValueError("Cannot combine tensors with \"{}\" "
"Only \"add\" and \"concat\" are "
"supported".format(self.combine))
self.first_1x1_groups = self.groups if first_block else 1
self.g_conv_1x1_compress = self._make_grouped_conv1x1(
self.inplanes,
self.bottleneck_channels,
self.first_1x1_groups,
batch_norm=True,
relu=True
)
self.depthwise_conv3x3 = conv3x3(self.bottleneck_channels,
self.bottleneck_channels,
stride=self.depthwise_stride,
groups=self.bottleneck_channels)
self.nn.BatchNorm2d_after_depthwise = \
nn.BatchNorm2d(self.bottleneck_channels)
self.g_conv_1x1_expand = \
self._make_grouped_conv1x1(self.bottleneck_channels,
self.planes,
self.groups,
batch_norm=True,
relu=False)
self.avgpool = nn.AvgPool2d(kernel_size=3, stride=2, padding=1)
self.relu = nn.ReLU(inplace=True)
@staticmethod
def _add(x, out):
# residual connection
return x + out
@staticmethod
def _concat(x, out):
# concatenate along channel axis
return torch.cat((x, out), 1)
@staticmethod
def _make_grouped_conv1x1(inplanes, planes, groups,
batch_norm=True, relu=False):
modules = OrderedDict()
conv = conv1x1(inplanes, planes, groups=groups)
modules['conv1x1'] = conv
if batch_norm:
modules['batch_norm'] = nn.BatchNorm2d(planes)
if relu:
modules['relu'] = nn.ReLU()
if len(modules) > 1:
return nn.Sequential(modules)
else:
return conv
def forward(self, x):
def _inner_forward(x):
residual = x
if self.combine == 'concat':
residual = self.avgpool(residual)
out = self.g_conv_1x1_compress(x)
out = channel_shuffle(out, self.groups)
out = self.depthwise_conv3x3(out)
out = self.nn.BatchNorm2d_after_depthwise(out)
out = self.g_conv_1x1_expand(out)
out = self._combine_func(residual, out)
return out
if self.with_cp and x.requires_grad:
out = cp.checkpoint(_inner_forward, x)
else:
out = _inner_forward(x)
out = self.relu(out)
return out
class ShuffleNetv1(BaseBackbone):
"""ShuffleNetv1 backbone.
Args:
groups (int): number of groups to be used in grouped
1x1 convolutions in each ShuffleUnit. Default is 3 for best
performance according to original paper.
widen_factor (float): Config of widen_factor.
out_indices (Sequence[int]): Output from which stages.
frozen_stages (int): Stages to be frozen (all param fixed). -1 means
not freezing any parameters.
bn_eval (bool): Whether to set BN layers as eval mode, namely, freeze
running stats (mean and var).
bn_frozen (bool): Whether to freeze weight and bias of BN layers.
with_cp (bool): Use checkpoint or not. Using checkpoint will save some
memory while slowing down the training speed.
"""
def __init__(self,
groups=3,
widen_factor=1.0,
out_indices=(0, 1, 2, 3),
frozen_stages=-1,
bn_eval=True,
bn_frozen=False,
with_cp=False):
super(ShuffleNetv1, self).__init__()
blocks = [3, 7, 3]
self.groups = groups
self.out_indices = out_indices
self.frozen_stages = frozen_stages
self.bn_eval = bn_eval
self.bn_frozen = bn_frozen
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("{} groups is not supported for "
"1x1 Grouped Convolutions".format(groups))
channels = [_make_divisible(ch * widen_factor, 8) for ch in channels]
self.inplanes = int(24 * widen_factor)
self.conv1 = conv3x3(3, self.inplanes, stride=2)
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.layer2 = self._make_layer(channels[0], blocks[0],
first_block=False, with_cp=with_cp)
self.layer3 = self._make_layer(channels[1], blocks[1], with_cp=with_cp)
self.layer4 = self._make_layer(channels[2], blocks[2], with_cp=with_cp)
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 _make_layer(self,
outplanes,
blocks,
first_block=True,
with_cp=False):
layers = []
for i in range(blocks):
if i == 0:
layers.append(ShuffleUnit(self.inplanes, outplanes,
groups=self.groups,
first_block=first_block,
combine='concat',
with_cp=with_cp))
else:
layers.append(ShuffleUnit(self.inplanes, outplanes,
groups=self.groups,
first_block=True,
combine='add',
with_cp=with_cp))
self.inplanes = outplanes
return nn.Sequential(*layers)
def forward(self, x):
x = self.conv1(x)
x = self.maxpool(x)
outs = []
if 0 in self.out_indices:
outs.append(x)
x = self.layer2(x)
if 1 in self.out_indices:
outs.append(x)
x = self.layer3(x)
if 2 in self.out_indices:
outs.append(x)
x = self.layer4(x)
if 3 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)
if self.bn_eval:
for m in self.modules():
if isinstance(m, nn.BatchNorm2d):
m.eval()
if self.bn_frozen:
for params in m.parameters():
params.requires_grad = False
if mode and self.frozen_stages >= 0:
for param in self.conv1.parameters():
param.requires_grad = False
for i in range(1, self.frozen_stages + 1):
mod = getattr(self, 'layer{}'.format(i))
mod.eval()
for param in mod.parameters():
param.requires_grad = False