|
| 1 | +import torch |
| 2 | +from torch import nn |
| 3 | +import torch.nn.functional as F |
| 4 | +import math |
| 5 | + |
| 6 | +device = torch.device("cuda" if torch.cuda.is_available() else "cpu") |
| 7 | + |
| 8 | +# 以下为无1×1卷积代码 |
| 9 | +class DoubleConv(nn.Module): |
| 10 | + def __init__(self, in_ch, out_ch): |
| 11 | + super(DoubleConv, self).__init__() |
| 12 | + self.conv = nn.Sequential( |
| 13 | + nn.Conv2d(in_ch, out_ch, 3, padding=1), |
| 14 | + nn.BatchNorm2d(out_ch), # 已添加BN层 |
| 15 | + # nn.GroupNorm(64, out_ch), # 在Batchsize比较小的时候,使用GN层替代BN层可以提升一定的模型精度 |
| 16 | + nn.ReLU(inplace=True), |
| 17 | + nn.Conv2d(out_ch, out_ch, 3, padding=1), |
| 18 | + nn.BatchNorm2d(out_ch), |
| 19 | + # nn.GroupNorm(64, out_ch), |
| 20 | + nn.ReLU(inplace=True) |
| 21 | + ) |
| 22 | + self.shortcut = nn.Sequential( |
| 23 | + nn.Conv2d(in_ch, out_ch, kernel_size=1, stride=1, bias=False), |
| 24 | + nn.BatchNorm2d(out_ch) |
| 25 | + # nn.GroupNorm(64, out_ch), |
| 26 | + ) |
| 27 | + |
| 28 | + def forward(self, input): |
| 29 | + out = self.conv(input) |
| 30 | + out = out + self.shortcut(input) |
| 31 | + out = F.relu(out) |
| 32 | + return out |
| 33 | + |
| 34 | +# double |
| 35 | +class sSE(nn.Module): |
| 36 | + def __init__(self, in_channels): |
| 37 | + super().__init__() |
| 38 | + self.Conv1x1 = nn.Conv2d(in_channels, 1, kernel_size=1, bias=False) |
| 39 | + self.norm = nn.Sigmoid() |
| 40 | + |
| 41 | + def forward(self, U): |
| 42 | + q = self.Conv1x1(U) # U:[bs,c,h,w] to q:[bs,1,h,w] |
| 43 | + q = self.norm(q) |
| 44 | + return U * q # 广播机制 |
| 45 | + |
| 46 | +class cSE(nn.Module): |
| 47 | + def __init__(self, in_channels): |
| 48 | + super().__init__() |
| 49 | + self.avgpool = nn.AdaptiveAvgPool2d(1) |
| 50 | + #self.# new |
| 51 | + self.Conv_Squeeze = nn.Conv2d(in_channels, in_channels // 2, kernel_size=1, bias=False) |
| 52 | + self.Conv_Excitation = nn.Conv2d(in_channels//2, in_channels, kernel_size=1, bias=False) |
| 53 | + self.norm = nn.Sigmoid() |
| 54 | + self.maxpool = nn.AdaptiveMaxPool2d(1, return_indices=False) |
| 55 | + |
| 56 | + def forward(self, U): |
| 57 | + z = self.avgpool(U)# shape: [bs, c, h, w] to [bs, c, 1, 1] |
| 58 | + z = self.Conv_Squeeze(z) # shape: [bs, c/2] |
| 59 | + z = self.Conv_Excitation(z) # shape: [bs, c] |
| 60 | + z = self.norm(z) |
| 61 | + x = self.maxpool(U) |
| 62 | + x = self.Conv_Squeeze(x) |
| 63 | + x = self.Conv_Excitation(x) |
| 64 | + x = self.norm(x) |
| 65 | + x = z + x |
| 66 | + return U * x.expand_as(U) |
| 67 | + |
| 68 | +# 多尺度卷积模块 |
| 69 | +class MultiScaleModule(nn.Module): |
| 70 | + def __init__(self, in_channels): |
| 71 | + super(MultiScaleModule, self).__init__() |
| 72 | + # 动态调整每个分支的通道数 |
| 73 | + branch_channels = in_channels // 4 |
| 74 | + if in_channels % 4 != 0: |
| 75 | + raise ValueError(f"in_channels ({in_channels}) must be divisible by 4 for MultiScaleModule.") |
| 76 | + |
| 77 | + self.conv0 = nn.Conv2d(in_channels, branch_channels, kernel_size=1, padding=0, bias=False) # 1x1卷积 |
| 78 | + self.conv1 = nn.Conv2d(in_channels, branch_channels, kernel_size=3, padding=1, bias=False) # 3x3卷积 |
| 79 | + self.conv2 = nn.Conv2d(in_channels, branch_channels, kernel_size=5, padding=2, bias=False) # 5x5卷积 |
| 80 | + self.conv3 = nn.Conv2d(in_channels, branch_channels, kernel_size=7, padding=3, bias=False) # 7x7卷积 |
| 81 | + self.norm = nn.BatchNorm2d(in_channels) # 对最终结果进行归一化 |
| 82 | + |
| 83 | + def forward(self, x): |
| 84 | + # 四个并行卷积 |
| 85 | + F0 = self.conv0(x) # 1x1卷积 |
| 86 | + F1 = self.conv1(x) # 3x3卷积 |
| 87 | + F2 = self.conv2(x) # 5x5卷积 |
| 88 | + F3 = self.conv3(x) # 7x7卷积 |
| 89 | + # 通道维度拼接 F0, F1, F2, F3 |
| 90 | + F_out = torch.cat([F0, F1, F2, F3], dim=1) # [B, C, H, W] |
| 91 | + F_out = self.norm(F_out) # 归一化 |
| 92 | + return F_out |
| 93 | + |
| 94 | +# scSE模块,结合MultiScaleModule |
| 95 | +class MRAM(nn.Module): |
| 96 | + def __init__(self, in_channels): |
| 97 | + super(MRAM, self).__init__() |
| 98 | + self.multi_scale = MultiScaleModule(in_channels) # 添加多尺度卷积模块 |
| 99 | + self.cSE = cSE(in_channels) |
| 100 | + self.sSE = sSE(in_channels) |
| 101 | + |
| 102 | + def forward(self, U): |
| 103 | + U = self.multi_scale(U) # 先经过多尺度卷积模块 |
| 104 | + U_cse = self.cSE(U) # 通道注意力 |
| 105 | + U_sse = self.sSE(U_cse) # 空间注意力 |
| 106 | + return U_sse + U # 残差连接 |
| 107 | + |
| 108 | + |
| 109 | +class MMRAN(nn.Module): |
| 110 | + def __init__(self, in_ch, out_ch, reduction_factor=4): |
| 111 | + super(MMRAN, self).__init__() |
| 112 | + # 确保 reduction_factor 只能取值 1, 2, 4 |
| 113 | + if reduction_factor not in [1, 2, 4]: |
| 114 | + raise ValueError(f"Invalid reduction_factor: {reduction_factor}. It must be 1, 2, or 4.") |
| 115 | + factor = reduction_factor |
| 116 | + print(f"Factor={factor} (default=4), all channels of Convolutional Layers will be reduced to 1 / {factor}.") |
| 117 | + |
| 118 | + # 通道数根据 factor 调整 |
| 119 | + self.conv1 = DoubleConv(in_ch, 64 // factor) # 原 64 |
| 120 | + self.conv2 = DoubleConv(64 // factor, 128 // factor) # 原 128 |
| 121 | + self.conv3 = DoubleConv(128 // factor, 256 // factor) # 原 256 |
| 122 | + self.conv4 = DoubleConv(256 // factor, 512 // factor) # 原 512 |
| 123 | + self.conv5 = DoubleConv(512 // factor, 1024 // factor) # 原 512 |
| 124 | + |
| 125 | + self.pool = nn.MaxPool2d(2) # 共享池化层 |
| 126 | + |
| 127 | + # 上采样分支 |
| 128 | + self.up6 = nn.ConvTranspose2d(1024 // factor, 512 // factor, 2, stride=2) # 原 1024->512 |
| 129 | + self.conv6 = DoubleConv(1024 // factor, 512 // factor) # 原 1024->512 |
| 130 | + |
| 131 | + self.up7 = nn.ConvTranspose2d(512 // factor, 256 // factor, 2, stride=2) # 原 512->256 |
| 132 | + self.conv7 = DoubleConv(512 // factor, 256 // factor) # 原 512->256 |
| 133 | + |
| 134 | + self.up8 = nn.ConvTranspose2d(256 // factor, 128 // factor, 2, stride=2) # 原 256->128 |
| 135 | + self.conv8 = DoubleConv(256 // factor, 128 // factor) # 原 256->128 |
| 136 | + |
| 137 | + self.up9 = nn.ConvTranspose2d(128 // factor, 64 // factor, 2, stride=2) # 原 128->64 |
| 138 | + self.conv9 = DoubleConv(128 // factor, 64 // factor) # 原 128->64 |
| 139 | + |
| 140 | + self.conv10 = nn.Conv2d(64 // factor, out_ch, 1) # 输出通道数不变 |
| 141 | + |
| 142 | + self.num_levels = 4 |
| 143 | + self.pool_type = 'max_pool' |
| 144 | + |
| 145 | + # 下采样分支 |
| 146 | + self.conv11 = DoubleConv(1024 // factor, 512 // factor) # 原 1024->512 |
| 147 | + self.conv12 = DoubleConv(512 // factor, 256 // factor) # 原 512->256 |
| 148 | + self.conv13 = DoubleConv(256 // factor, 128 // factor) # 原 256->128 |
| 149 | + self.conv14 = DoubleConv(128 // factor, 64 // factor) # 原 128->64 |
| 150 | + |
| 151 | + self.fc1 = nn.Linear(1920 // factor, 100) # 原 1920,减半 |
| 152 | + self.fc2 = nn.Linear(100, 3) # 3分类 |
| 153 | + |
| 154 | + self.c_se1 = MRAM(64 // factor) |
| 155 | + self.c_se2 = MRAM(128 // factor) |
| 156 | + self.c_se3 = MRAM(256 // factor) |
| 157 | + self.c_se4 = MRAM(512 // factor) |
| 158 | + |
| 159 | + def forward(self, x): |
| 160 | + x = self.conv1(x) # 512 * 512 * (32/64) |
| 161 | + att1 = self.c_se1(x) |
| 162 | + x = self.pool(x) # 256 * 256 * (32/64) |
| 163 | + |
| 164 | + x = self.conv2(x) # 256 * 256 * (64/128) |
| 165 | + att2 = self.c_se2(x) |
| 166 | + x = self.pool(x) # 128 * 128 * (64/128) |
| 167 | + |
| 168 | + x = self.conv3(x) # 128 * 128 * (128/256) |
| 169 | + att3 = self.c_se3(x) |
| 170 | + x = self.pool(x) # 64 * 64 * (128/256) |
| 171 | + |
| 172 | + x = self.conv4(x) # 64 * 64 * (256/512) |
| 173 | + att4 = self.c_se4(x) |
| 174 | + x = self.pool(x) # 32 * 32 * (256/512) |
| 175 | + |
| 176 | + x = self.conv5(x) # 32 * 32 * (256/512)\ |
| 177 | + |
| 178 | + # 在本文中并没有使用这个模块,但是您也可以加上以提升性能 |
| 179 | + # x = self.psp(x) #在网络最底层增加了多尺度融合 |
| 180 | + |
| 181 | + # 上采样部分 |
| 182 | + x_up = self.up6(x) # 64 * 64 * (256/512) |
| 183 | + x_up = torch.cat([x_up, att4], dim=1) # 64 * 64 * (512/1024) |
| 184 | + x_up = self.conv6(x_up) # 64 * 64 * (512/1024) |
| 185 | + |
| 186 | + x_up = self.up7(x_up) # 128 * 128 * (128/256) |
| 187 | + x_up = torch.cat([x_up, att3], dim=1) # 128 * 128 * (256/512) |
| 188 | + x_up = self.conv7(x_up) # 128 * 128 * (128/256) |
| 189 | + |
| 190 | + x_up = self.up8(x_up) # 256 * 256 * (64/128) |
| 191 | + x_up = torch.cat([x_up, att2], dim=1) # 256 * 256 * (128/256) |
| 192 | + x_up = self.conv8(x_up) # 256 * 256 * (64/128) |
| 193 | + |
| 194 | + x_up = self.up9(x_up) # 512 * 512 * (32/64) |
| 195 | + x_up = torch.cat([x_up, att1], dim=1) # 512 * 512 * (64/128) |
| 196 | + x_up = self.conv9(x_up) # 512 * 512 * (32/64) |
| 197 | + |
| 198 | + seg_output = self.conv10(x_up) # 512 * 512 * out_ch |
| 199 | + |
| 200 | + # CNN部分 |
| 201 | + x = self.conv11(x) # 32 * 32 * (256/512) |
| 202 | + x = self.pool(x) # 16 * 16 * (256/512) |
| 203 | + x = self.conv12(x) # 16 * 16 * (128/256) |
| 204 | + |
| 205 | + # 在本文中并没有使用这个模块,但是您也可以加上以提升性能 |
| 206 | + # x = self.psp2(x) |
| 207 | + x = self.pool(x) # 8 * 8 * (128/256) |
| 208 | + x = self.conv13(x) # 8 * 8 * (64/128) |
| 209 | + x = self.pool(x) # 4 * 4 * (64/128) |
| 210 | + x = self.conv14(x) # 4 * 4 * (32/64) |
| 211 | + |
| 212 | + # SPP 层 |
| 213 | + spp_layer = SPPLayer(self.num_levels, self.pool_type) |
| 214 | + x = spp_layer(x) |
| 215 | + |
| 216 | + x = F.relu(self.fc1(x)) |
| 217 | + cls_output = self.fc2(x) |
| 218 | + |
| 219 | + return seg_output, cls_output |
| 220 | + |
| 221 | + |
| 222 | +class focal_loss(nn.Module): |
| 223 | + def __init__(self, alpha=0.25, gamma=2, num_classes=3, size_average=True): |
| 224 | + """ |
| 225 | + focal_loss损失函数, -α(1-yi)**γ *ce_loss(xi,yi) |
| 226 | + 步骤详细的实现了 focal_loss损失函数. |
| 227 | + :param alpha: 阿尔法α,类别权重. 当α是列表时,为各类别权重,当α为常数时,类别权重为[α, 1-α, 1-α, ....],常用于 目标检测算法中抑制背景类 , retainnet中设置为0.25 |
| 228 | + :param gamma: 伽马γ,难易样本调节参数. retainnet中设置为2 |
| 229 | + :param num_classes: 类别数量 |
| 230 | + :param size_average: 损失计算方式,默认取均值 |
| 231 | + """ |
| 232 | + |
| 233 | + super(focal_loss, self).__init__() |
| 234 | + self.size_average = size_average |
| 235 | + if isinstance(alpha, list): |
| 236 | + assert len(alpha) == num_classes # α可以以list方式输入,size:[num_classes] 用于对不同类别精细地赋予权重 |
| 237 | + print("Focal_loss alpha = {}, Fine tune the assignment of weights for each category".format(alpha)) |
| 238 | + self.alpha = torch.Tensor(alpha) |
| 239 | + else: |
| 240 | + assert alpha < 1 # 如果α为一个常数,则降低第一类的影响,在目标检测中为第一类 |
| 241 | + print(" --- Focal_loss alpha = {} --- ".format(alpha)) |
| 242 | + self.alpha = torch.zeros(num_classes) |
| 243 | + self.alpha[0] += alpha |
| 244 | + self.alpha[1:] += (1 - alpha) # α 最终为 [ α, 1-α, 1-α, 1-α, 1-α, ...] size:[num_classes] |
| 245 | + self.gamma = gamma |
| 246 | + |
| 247 | + def forward(self, preds, labels): |
| 248 | + """ |
| 249 | + focal_loss损失计算 |
| 250 | + :param preds: 预测类别. size:[B,N,C] or [B,C] 分别对应与检测与分类任务, B 批次, N检测框数, C类别数 |
| 251 | + :param labels: 实际类别. size:[B,N] or [B] |
| 252 | + :return: |
| 253 | + """ |
| 254 | + # assert preds.dim()==2 and labels.dim()==1 |
| 255 | + preds = preds.view(-1, preds.size(-1)) |
| 256 | + self.alpha = self.alpha.to(preds.device) |
| 257 | + preds_softmax = F.softmax(preds, |
| 258 | + dim=1) # 这里并没有直接使用log_softmax, 因为后面会用到softmax的结果(当然你也可以使用log_softmax,然后进行exp操作) |
| 259 | + preds_logsoft = torch.log(preds_softmax) |
| 260 | + preds_softmax = preds_softmax.gather(1, labels.view(-1, 1)) # 这部分实现nll_loss ( crossempty = log_softmax + nll ) |
| 261 | + preds_logsoft = preds_logsoft.gather(1, labels.view(-1, 1)) |
| 262 | + self.alpha = self.alpha.gather(0, labels.view(-1)) |
| 263 | + loss = -torch.mul(torch.pow((1 - preds_softmax), self.gamma), |
| 264 | + preds_logsoft) # torch.pow((1-preds_softmax), self.gamma) 为focal loss中 (1-pt)**γ |
| 265 | + loss = torch.mul(self.alpha, loss.t()) |
| 266 | + if self.size_average: |
| 267 | + loss = loss.mean() |
| 268 | + else: |
| 269 | + loss = loss.sum() |
| 270 | + return loss |
| 271 | + |
| 272 | + |
| 273 | +class DiceLoss(nn.Module): |
| 274 | + def __init__(self): |
| 275 | + super(DiceLoss, self).__init__() |
| 276 | + self.epsilon = 1e-5 |
| 277 | + |
| 278 | + def forward(self, predict, target): |
| 279 | + assert predict.size() == target.size(), "the size of predict and target must be equal." |
| 280 | + num = predict.size(0) |
| 281 | + |
| 282 | + pre = torch.sigmoid(predict).view(num, -1) |
| 283 | + tar = target.view(num, -1) |
| 284 | + |
| 285 | + intersection = (pre * tar).sum(-1).sum() # 利用预测值与标签相乘当作交集 |
| 286 | + union = (pre + tar).sum(-1).sum() |
| 287 | + |
| 288 | + score = 1 - 2 * (intersection + self.epsilon) / (union + self.epsilon) |
| 289 | + |
| 290 | + return score |
| 291 | + |
| 292 | + |
| 293 | +class SPPLayer(torch.nn.Module): |
| 294 | + |
| 295 | + def __init__(self, num_levels, pool_type='max_pool'): |
| 296 | + super(SPPLayer, self).__init__() |
| 297 | + |
| 298 | + self.num_levels = num_levels |
| 299 | + self.pool_type = pool_type |
| 300 | + |
| 301 | + def forward(self, x): |
| 302 | + # num:样本数量 c:通道数 h:高 w:宽 |
| 303 | + # num: the number of samples |
| 304 | + # c: the number of channels |
| 305 | + # h: height |
| 306 | + # w: width |
| 307 | + num, c, h, w = x.size() |
| 308 | + # print(x.size()) |
| 309 | + for i in range(self.num_levels): |
| 310 | + level = i+1 |
| 311 | + |
| 312 | + ''' |
| 313 | + The equation is explained on the following site: |
| 314 | + http://www.cnblogs.com/marsggbo/p/8572846.html#autoid-0-0-0 |
| 315 | + ''' |
| 316 | + kernel_size = (math.ceil(h / level), math.ceil(w / level)) |
| 317 | + stride = (math.floor(h / level), math.floor(w / level)) |
| 318 | + pooling = (math.floor((kernel_size[0]*level-h+1)/2), math.floor((kernel_size[1]*level-w+1)/2)) |
| 319 | + |
| 320 | + # update input data with padding |
| 321 | + zero_pad = torch.nn.ZeroPad2d((pooling[1],pooling[1],pooling[0],pooling[0])) |
| 322 | + x_new = zero_pad(x) |
| 323 | + |
| 324 | + # update kernel and stride |
| 325 | + h_new = 2*pooling[0] + h |
| 326 | + w_new = 2*pooling[1] + w |
| 327 | + |
| 328 | + kernel_size = (math.ceil(h_new / level), math.ceil(w_new / level)) |
| 329 | + stride = (math.floor(h_new / level), math.floor(w_new / level)) |
| 330 | + |
| 331 | + |
| 332 | + # 选择池化方式 |
| 333 | + if self.pool_type == 'max_pool': |
| 334 | + try: |
| 335 | + tensor = F.max_pool2d(x_new, kernel_size=kernel_size, stride=stride).view(num, -1) |
| 336 | + except Exception as e: |
| 337 | + print(str(e)) |
| 338 | + print(x.size()) |
| 339 | + print(level) |
| 340 | + else: |
| 341 | + tensor = F.avg_pool2d(x_new, kernel_size=kernel_size, stride=stride).view(num, -1) |
| 342 | + |
| 343 | + # 展开、拼接 |
| 344 | + if (i == 0): |
| 345 | + x_flatten = tensor.view(num, -1) |
| 346 | + else: |
| 347 | + x_flatten = torch.cat((x_flatten, tensor.view(num, -1)), 1) |
| 348 | + return x_flatten |
| 349 | + |
| 350 | + |
| 351 | + # PSP模块,以下两个模块在文中并没有用到,但是您也可以在网络中使用它们,对分类效果的提升有一定的帮助。 |
| 352 | +class PSPModule(nn.Module): |
| 353 | + def __init__(self, features, out_features, sizes=(1, 2, 3, 6)): |
| 354 | + super().__init__() |
| 355 | + self.stages = [] |
| 356 | + self.stages = nn.ModuleList([self._make_stage(features, size) for size in sizes]) |
| 357 | + self.bottleneck = nn.Conv2d(features * (len(sizes) + 1), out_features, kernel_size=1) |
| 358 | + self.relu = nn.ReLU() |
| 359 | + |
| 360 | + def _make_stage(self, features, size): |
| 361 | + # prior = nn.AdaptiveAvgPool2d(output_size=(size, size)) |
| 362 | + prior = nn.AdaptiveMaxPool2d(output_size=(size, size)) |
| 363 | + conv = nn.Conv2d(features, features, kernel_size=1, bias=False) #第一次加入多尺度模块时没加1*1卷积层,但是精度也有不错的提升 |
| 364 | + return nn.Sequential(prior, conv) |
| 365 | + #return nn.Sequential(prior) |
| 366 | + def forward(self, feats): |
| 367 | + h, w = feats.size(2), feats.size(3) |
| 368 | + priors = [F.upsample(input=stage(feats), size=(h, w), mode='bilinear') for stage in self.stages] + [feats] |
| 369 | + bottle = self.bottleneck(torch.cat(priors, 1)) # 1代表cat按列拼 |
| 370 | + return self.relu(bottle) |
| 371 | + |
| 372 | +class PSPModule2(nn.Module): |
| 373 | + def __init__(self, features, out_features, size=(1,2,3,6)): |
| 374 | + super().__init__() |
| 375 | + self.pool1 = nn.MaxPool2d(1) |
| 376 | + self.pool2 = nn.MaxPool2d(2) |
| 377 | + self.pool3 = nn.MaxPool2d(3) |
| 378 | + self.pool4 = nn.MaxPool2d(6) |
| 379 | + self.bottleneck = nn.Conv2d(features * 4, out_features, kernel_size=1) |
| 380 | + self.relu = nn.ReLU() |
| 381 | + |
| 382 | + def forward(self, x): # x:512 * 64 |
| 383 | + p1 = F.interpolate(self.pool1(x), size = [16, 16]) # 512 * 64 |
| 384 | + p2 = F.interpolate(self.pool2(x), size = [16, 16]) # 256 * 64 |
| 385 | + p3 = F.interpolate(self.pool3(x), size = [16, 16]) # 170 * 64 |
| 386 | + p4 = F.interpolate(self.pool4(x), size = [16, 16]) # 85 * 64 |
| 387 | + x = self.bottleneck(torch.cat([p1, p2, p3, p4], 1)) |
| 388 | + return self.relu(x) |
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