Thesis-Dual Attention Network for Scene Segmentation
作者：互联网
Thesis-Dual Attention Network for Scene Segmentation
Dual Attention Network for Scene Segmentation
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DaNet.py
"""Dual Attention Network"""
import torch
import torch.nn as nn
import torch.nn.functional as F
from backbone import ResNet50
class DANet(ResNet50):
r"""Pyramid Scene Parsing Network
Parameters
----------
nclass : int
Number of categories for the training dataset.
backbone : string
Pre-trained dilated backbone network type (default:'resnet50'; 'resnet50',
'resnet101' or 'resnet152').
norm_layer : object
Normalization layer used in backbone network (default: :class:`mxnet.gluon.nn.BatchNorm`;
for Synchronized Cross-GPU BachNormalization).
aux : bool
Auxiliary loss.
Reference:
Jun Fu, Jing Liu, Haijie Tian, Yong Li, Yongjun Bao, Zhiwei Fang,and Hanqing Lu.
"Dual Attention Network for Scene Segmentation." *CVPR*, 2019
"""
def __init__(self, nclass, aux=True, **kwargs):
super(DANet, self).__init__(nclass)
self.head = _DAHead(2048, nclass, aux, **kwargs)
self.aux = True
self.__setattr__('exclusive', ['head'])
def forward(self, x):
size = x.size()[2:]
feature_map,_ = self.base_forward(x)
c3,c4 = feature_map[2],feature_map[3]
outputs = []
x = self.head(c4)
x0 = F.interpolate(x[0], size, mode='bilinear', align_corners=True)
outputs.append(x0)
if self.aux:
#print('x[1]:{}'.format(x[1].shape))
x1 = F.interpolate(x[1], size, mode='bilinear', align_corners=True)
x2 = F.interpolate(x[2], size, mode='bilinear', align_corners=True)
outputs.append(x1)
outputs.append(x2)
return outputs
class _PositionAttentionModule(nn.Module):
""" Position attention module"""
def __init__(self, in_channels, **kwargs):
super(_PositionAttentionModule, self).__init__()
self.conv_b = nn.Conv2d(in_channels, in_channels // 8, 1)
self.conv_c = nn.Conv2d(in_channels, in_channels // 8, 1)
self.conv_d = nn.Conv2d(in_channels, in_channels, 1)
self.alpha = nn.Parameter(torch.zeros(1))
self.softmax = nn.Softmax(dim=-1)
def forward(self, x):
batch_size, _, height, width = x.size()
feat_b = self.conv_b(x).view(batch_size, -1, height * width).permute(0, 2, 1)
feat_c = self.conv_c(x).view(batch_size, -1, height * width)
attention_s = self.softmax(torch.bmm(feat_b, feat_c))
feat_d = self.conv_d(x).view(batch_size, -1, height * width)
feat_e = torch.bmm(feat_d, attention_s.permute(0, 2, 1)).view(batch_size, -1, height, width)
out = self.alpha * feat_e + x
return out
class _ChannelAttentionModule(nn.Module):
"""Channel attention module"""
def __init__(self, **kwargs):
super(_ChannelAttentionModule, self).__init__()
self.beta = nn.Parameter(torch.zeros(1))
self.softmax = nn.Softmax(dim=-1)
def forward(self, x):
batch_size, _, height, width = x.size()
feat_a = x.view(batch_size, -1, height * width)
feat_a_transpose = x.view(batch_size, -1, height * width).permute(0, 2, 1)
attention = torch.bmm(feat_a, feat_a_transpose)
attention_new = torch.max(attention, dim=-1, keepdim=True)[0].expand_as(attention) - attention
attention = self.softmax(attention_new)
feat_e = torch.bmm(attention, feat_a).view(batch_size, -1, height, width)
out = self.beta * feat_e + x
return out
class _DAHead(nn.Module):
def __init__(self, in_channels, nclass, aux=True, norm_layer=nn.BatchNorm2d, norm_kwargs=None, **kwargs):
super(_DAHead, self).__init__()
self.aux = aux
inter_channels = in_channels // 4
self.conv_p1 = nn.Sequential(
nn.Conv2d(in_channels, inter_channels, 3, padding=1, bias=False),
norm_layer(inter_channels, **({} if norm_kwargs is None else norm_kwargs)),
nn.ReLU(True)
)
self.conv_c1 = nn.Sequential(
nn.Conv2d(in_channels, inter_channels, 3, padding=1, bias=False),
norm_layer(inter_channels, **({} if norm_kwargs is None else norm_kwargs)),
nn.ReLU(True)
)
self.pam = _PositionAttentionModule(inter_channels, **kwargs)
self.cam = _ChannelAttentionModule(**kwargs)
self.conv_p2 = nn.Sequential(
nn.Conv2d(inter_channels, inter_channels, 3, padding=1, bias=False),
norm_layer(inter_channels, **({} if norm_kwargs is None else norm_kwargs)),
nn.ReLU(True)
)
self.conv_c2 = nn.Sequential(
nn.Conv2d(inter_channels, inter_channels, 3, padding=1, bias=False),
norm_layer(inter_channels, **({} if norm_kwargs is None else norm_kwargs)),
nn.ReLU(True)
)
self.out = nn.Sequential(
nn.Dropout(0.1),
nn.Conv2d(inter_channels, nclass, 1)
)
if aux:
self.conv_p3 = nn.Sequential(
nn.Dropout(0.1),
nn.Conv2d(inter_channels, nclass, 1)
)
self.conv_c3 = nn.Sequential(
nn.Dropout(0.1),
nn.Conv2d(inter_channels, nclass, 1)
)
def forward(self, x):
feat_p = self.conv_p1(x)
feat_p = self.pam(feat_p)
feat_p = self.conv_p2(feat_p)
feat_c = self.conv_c1(x)
feat_c = self.cam(feat_c)
feat_c = self.conv_c2(feat_c)
feat_fusion = feat_p + feat_c
outputs = []
fusion_out = self.out(feat_fusion)
outputs.append(fusion_out)
if self.aux:
p_out = self.conv_p3(feat_p)
c_out = self.conv_c3(feat_c)
outputs.append(p_out)
outputs.append(c_out)
return tuple(outputs)
def get_danet( backbone='resnet50', pretrained_base=True, **kwargs):
cityspaces_numclass = 19
model = DANet(cityspaces_numclass, backbone=backbone, pretrained_base=pretrained_base, **kwargs)
return model
if __name__ == '__main__':
img = torch.randn(2, 3, 480, 480)
model = get_danet()
outputs = model(img)
#print(outputs)
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backbone.py
import torch.nn as nn
import torch
import resnet
from torch.nn import functional as F
class ResNet50(nn.Module):
def __init__(self, pretrained=True):
"""Declare all needed layers."""
super(ResNet50, self).__init__()
self.model = resnet.resnet50(pretrained=pretrained)
self.relu = self.model.relu # Place a hook
layers_cfg = [4, 5, 6, 7]
self.blocks = []
for i, num_this_layer in enumerate(layers_cfg):
self.blocks.append(list(self.model.children())[num_this_layer])
def base_forward(self, x):
feature_map = []
x = self.model.conv1(x)
x = self.model.bn1(x)
x = self.model.relu(x)
x = self.model.maxpool(x)
for i, block in enumerate(self.blocks):
x = block(x)
feature_map.append(x)
out = nn.AvgPool2d(x.shape[2:])(x).view(x.shape[0], -1)
return feature_map, out
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resnet.py
import torch.nn as nn
import math
import torch.utils.model_zoo as model_zoo
__all__ = ['ResNet', 'resnet50']
model_urls = {
'resnet50': 'https://download.pytorch.org/models/resnet50-19c8e357.pth',
}
def conv3x3(in_planes, out_planes, stride=1):
"""3x3 convolution with padding"""
return nn.Conv2d(in_planes, out_planes, kernel_size=3, stride=stride,
padding=1, bias=False)
class Bottleneck(nn.Module):
expansion = 4
def __init__(self, inplanes, planes, stride=1, downsample=None, rate=1):
super(Bottleneck, self).__init__()
self.conv1 = nn.Conv2d(inplanes, planes, kernel_size=1, bias=False)
self.bn1 = nn.BatchNorm2d(planes)
self.conv2 = nn.Conv2d(planes, planes, kernel_size=3, stride=stride,
padding=rate, dilation=rate, bias=False)
self.bn2 = nn.BatchNorm2d(planes)
self.conv3 = nn.Conv2d(planes, planes * self.expansion, kernel_size=1, bias=False)
self.bn3 = nn.BatchNorm2d(planes * self.expansion)
self.relu = nn.ReLU(inplace=True)
self.downsample = downsample
self.stride = stride
def forward(self, x):
residual = x
out = self.conv1(x)
out = self.bn1(out)
out = self.relu(out)
out = self.conv2(out)
out = self.bn2(out)
out = self.relu(out)
out = self.conv3(out)
out = self.bn3(out)
if self.downsample is not None:
residual = self.downsample(x)
out += residual
out = self.relu(out)
return out
class ResNet(nn.Module):
def __init__(self, block, layers, num_classes=1000):
self.inplanes = 64
super(ResNet, self).__init__()
self.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3,
bias=False)
self.bn1 = nn.BatchNorm2d(64)
self.relu = nn.ReLU(inplace=True)
self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1)
self.layer1 = self._make_layer(block, 64, layers[0])
self.layer2 = self._make_layer(block, 128, layers[1], stride=2)
self.layer3 = self._make_layer(block, 256, layers[2], stride=2)
rates = [1, 2, 4]
self.layer4 = self._make_deeplabv3_layer(block, 512, layers[3], rates=rates, stride=1) # stride 2 => stride 1
self.avgpool = nn.AvgPool2d(7, stride=1)
self.fc = nn.Linear(512 * block.expansion, num_classes)
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')
elif isinstance(m, nn.BatchNorm2d):
nn.init.constant_(m.weight, 1)
nn.init.constant_(m.bias, 0)
def _make_layer(self, block, planes, blocks, stride=1):
downsample = None
if stride != 1 or self.inplanes != planes * block.expansion:
downsample = nn.Sequential(
nn.Conv2d(self.inplanes, planes * block.expansion,
kernel_size=1, stride=stride, bias=False),
nn.BatchNorm2d(planes * block.expansion),
)
layers = []
layers.append(block(self.inplanes, planes, stride, downsample))
self.inplanes = planes * block.expansion
for i in range(1, blocks):
layers.append(block(self.inplanes, planes))
return nn.Sequential(*layers)
def _make_deeplabv3_layer(self, block, planes, blocks, rates, stride=1):
downsample = None
if stride != 1 or self.inplanes != planes * block.expansion:
downsample = nn.Sequential(
nn.Conv2d(self.inplanes, planes * block.expansion,
kernel_size=1, stride=stride, bias=False),
nn.BatchNorm2d(planes * block.expansion),
)
layers = []
layers.append(block(self.inplanes, planes, stride, downsample))
self.inplanes = planes * block.expansion
for i in range(1, blocks):
layers.append(block(self.inplanes, planes, rate=rates[i]))
return nn.Sequential(*layers)
def forward(self, x):
x = self.conv1(x)
x = self.bn1(x)
x = self.relu(x)
x = self.maxpool(x)
x = self.layer1(x)
x = self.layer2(x)
x = self.layer3(x)
x = self.layer4(x)
x = self.avgpool(x)
x = x.view(x.size(0), -1)
x = self.fc(x)
return x
def resnet50(pretrained=False, **kwargs):
"""Constructs a ResNet-50 model.
Args:
pretrained (bool): If True, returns a model pre-trained on ImageNet
"""
model = ResNet(Bottleneck, [3, 4, 6, 3], **kwargs)
if pretrained:
model.load_state_dict(model_zoo.load_url(model_urls['resnet50']))
return model
标签：__,Segmentation,nn,self,Attention,Thesis,planes,feat,out 来源： https://www.cnblogs.com/lwp-nicol/p/16583125.html