|
| 1 | +# -*- coding: utf-8 -*- |
| 2 | +from __future__ import print_function, division |
| 3 | + |
| 4 | +import math |
| 5 | +import torch |
| 6 | +from torch import nn |
| 7 | +import torch.nn.functional as F |
| 8 | + |
| 9 | +from timm.models.layers import trunc_normal_ |
| 10 | +from mamba_ssm import Mamba |
| 11 | + |
| 12 | + |
| 13 | +class PVMLayer(nn.Module): |
| 14 | + def __init__(self, input_dim, output_dim, d_state = 16, d_conv = 4, expand = 2): |
| 15 | + super().__init__() |
| 16 | + self.input_dim = input_dim |
| 17 | + self.output_dim = output_dim |
| 18 | + self.norm = nn.LayerNorm(input_dim) |
| 19 | + self.mamba = Mamba( |
| 20 | + d_model=input_dim//4, # Model dimension d_model |
| 21 | + d_state=d_state, # SSM state expansion factor |
| 22 | + d_conv=d_conv, # Local convolution width |
| 23 | + expand=expand, # Block expansion factor |
| 24 | + ) |
| 25 | + self.proj = nn.Linear(input_dim, output_dim) |
| 26 | + self.skip_scale= nn.Parameter(torch.ones(1)) |
| 27 | + |
| 28 | + def forward(self, x): |
| 29 | + if x.dtype == torch.float16: |
| 30 | + x = x.type(torch.float32) |
| 31 | + B, C = x.shape[:2] |
| 32 | + assert C == self.input_dim |
| 33 | + n_tokens = x.shape[2:].numel() |
| 34 | + img_dims = x.shape[2:] |
| 35 | + x_flat = x.reshape(B, C, n_tokens).transpose(-1, -2) |
| 36 | + x_norm = self.norm(x_flat) |
| 37 | + |
| 38 | + x1, x2, x3, x4 = torch.chunk(x_norm, 4, dim=2) |
| 39 | + x_mamba1 = self.mamba(x1) + self.skip_scale * x1 |
| 40 | + x_mamba2 = self.mamba(x2) + self.skip_scale * x2 |
| 41 | + x_mamba3 = self.mamba(x3) + self.skip_scale * x3 |
| 42 | + x_mamba4 = self.mamba(x4) + self.skip_scale * x4 |
| 43 | + x_mamba = torch.cat([x_mamba1, x_mamba2,x_mamba3,x_mamba4], dim=2) |
| 44 | + |
| 45 | + x_mamba = self.norm(x_mamba) |
| 46 | + x_mamba = self.proj(x_mamba) |
| 47 | + out = x_mamba.transpose(-1, -2).reshape(B, self.output_dim, *img_dims) |
| 48 | + return out |
| 49 | + |
| 50 | + |
| 51 | +class Channel_Att_Bridge(nn.Module): |
| 52 | + def __init__(self, c_list, split_att='fc'): |
| 53 | + super().__init__() |
| 54 | + c_list_sum = sum(c_list) - c_list[-1] |
| 55 | + self.split_att = split_att |
| 56 | + self.avgpool = nn.AdaptiveAvgPool2d(1) |
| 57 | + self.get_all_att = nn.Conv1d(1, 1, kernel_size=3, padding=1, bias=False) |
| 58 | + self.att1 = nn.Linear(c_list_sum, c_list[0]) if split_att == 'fc' else nn.Conv1d(c_list_sum, c_list[0], 1) |
| 59 | + self.att2 = nn.Linear(c_list_sum, c_list[1]) if split_att == 'fc' else nn.Conv1d(c_list_sum, c_list[1], 1) |
| 60 | + self.att3 = nn.Linear(c_list_sum, c_list[2]) if split_att == 'fc' else nn.Conv1d(c_list_sum, c_list[2], 1) |
| 61 | + self.att4 = nn.Linear(c_list_sum, c_list[3]) if split_att == 'fc' else nn.Conv1d(c_list_sum, c_list[3], 1) |
| 62 | + self.att5 = nn.Linear(c_list_sum, c_list[4]) if split_att == 'fc' else nn.Conv1d(c_list_sum, c_list[4], 1) |
| 63 | + self.sigmoid = nn.Sigmoid() |
| 64 | + |
| 65 | + def forward(self, t1, t2, t3, t4, t5): |
| 66 | + att = torch.cat((self.avgpool(t1), |
| 67 | + self.avgpool(t2), |
| 68 | + self.avgpool(t3), |
| 69 | + self.avgpool(t4), |
| 70 | + self.avgpool(t5)), dim=1) |
| 71 | + att = self.get_all_att(att.squeeze(-1).transpose(-1, -2)) |
| 72 | + if self.split_att != 'fc': |
| 73 | + att = att.transpose(-1, -2) |
| 74 | + att1 = self.sigmoid(self.att1(att)) |
| 75 | + att2 = self.sigmoid(self.att2(att)) |
| 76 | + att3 = self.sigmoid(self.att3(att)) |
| 77 | + att4 = self.sigmoid(self.att4(att)) |
| 78 | + att5 = self.sigmoid(self.att5(att)) |
| 79 | + if self.split_att == 'fc': |
| 80 | + att1 = att1.transpose(-1, -2).unsqueeze(-1).expand_as(t1) |
| 81 | + att2 = att2.transpose(-1, -2).unsqueeze(-1).expand_as(t2) |
| 82 | + att3 = att3.transpose(-1, -2).unsqueeze(-1).expand_as(t3) |
| 83 | + att4 = att4.transpose(-1, -2).unsqueeze(-1).expand_as(t4) |
| 84 | + att5 = att5.transpose(-1, -2).unsqueeze(-1).expand_as(t5) |
| 85 | + else: |
| 86 | + att1 = att1.unsqueeze(-1).expand_as(t1) |
| 87 | + att2 = att2.unsqueeze(-1).expand_as(t2) |
| 88 | + att3 = att3.unsqueeze(-1).expand_as(t3) |
| 89 | + att4 = att4.unsqueeze(-1).expand_as(t4) |
| 90 | + att5 = att5.unsqueeze(-1).expand_as(t5) |
| 91 | + |
| 92 | + return att1, att2, att3, att4, att5 |
| 93 | + |
| 94 | + |
| 95 | +class Spatial_Att_Bridge(nn.Module): |
| 96 | + def __init__(self): |
| 97 | + super().__init__() |
| 98 | + self.shared_conv2d = nn.Sequential(nn.Conv2d(2, 1, 7, stride=1, padding=9, dilation=3), |
| 99 | + nn.Sigmoid()) |
| 100 | + |
| 101 | + def forward(self, t1, t2, t3, t4, t5): |
| 102 | + t_list = [t1, t2, t3, t4, t5] |
| 103 | + att_list = [] |
| 104 | + for t in t_list: |
| 105 | + avg_out = torch.mean(t, dim=1, keepdim=True) |
| 106 | + max_out, _ = torch.max(t, dim=1, keepdim=True) |
| 107 | + att = torch.cat([avg_out, max_out], dim=1) |
| 108 | + att = self.shared_conv2d(att) |
| 109 | + att_list.append(att) |
| 110 | + return att_list[0], att_list[1], att_list[2], att_list[3], att_list[4] |
| 111 | + |
| 112 | + |
| 113 | +class SC_Att_Bridge(nn.Module): |
| 114 | + def __init__(self, c_list, split_att='fc'): |
| 115 | + super().__init__() |
| 116 | + |
| 117 | + self.catt = Channel_Att_Bridge(c_list, split_att=split_att) |
| 118 | + self.satt = Spatial_Att_Bridge() |
| 119 | + |
| 120 | + def forward(self, t1, t2, t3, t4, t5): |
| 121 | + r1, r2, r3, r4, r5 = t1, t2, t3, t4, t5 |
| 122 | + |
| 123 | + satt1, satt2, satt3, satt4, satt5 = self.satt(t1, t2, t3, t4, t5) |
| 124 | + t1, t2, t3, t4, t5 = satt1 * t1, satt2 * t2, satt3 * t3, satt4 * t4, satt5 * t5 |
| 125 | + |
| 126 | + r1_, r2_, r3_, r4_, r5_ = t1, t2, t3, t4, t5 |
| 127 | + t1, t2, t3, t4, t5 = t1 + r1, t2 + r2, t3 + r3, t4 + r4, t5 + r5 |
| 128 | + |
| 129 | + catt1, catt2, catt3, catt4, catt5 = self.catt(t1, t2, t3, t4, t5) |
| 130 | + t1, t2, t3, t4, t5 = catt1 * t1, catt2 * t2, catt3 * t3, catt4 * t4, catt5 * t5 |
| 131 | + |
| 132 | + return t1 + r1_, t2 + r2_, t3 + r3_, t4 + r4_, t5 + r5_ |
| 133 | + |
| 134 | + |
| 135 | +class UltraLight_VM_UNet(nn.Module): |
| 136 | + def __init__(self, params): |
| 137 | + """ |
| 138 | + UltraLight_VM_UNet that is a lightweight model using CNN and Mamba. |
| 139 | +
|
| 140 | + * Reference: Renkai Wu, Yinghao Liu, Pengchen Liang, Qing Chang. |
| 141 | + UltraLight VM-UNet: Parallel Vision Mamba Significantly Reduces Parameters for Skin Lesion Segmentation. |
| 142 | + arxiv 2403.20035, 2024. |
| 143 | +
|
| 144 | + The implementation is based on the code at: |
| 145 | + https://github.com/wurenkai/UltraLight-VM-UNet. |
| 146 | +
|
| 147 | + The parameters for the backbone should be given in the `params` dictionary. |
| 148 | + |
| 149 | + :param in_chns: (int) Input channel number. |
| 150 | + :param class_num: (int) The class number for segmentation task. |
| 151 | + :param feature_chns: (list) Feature channel for each resolution level. |
| 152 | + The length should be 6, by default it is [8, 16, 24, 32, 48, 64]. |
| 153 | + :param bridge: (int) If the bridge based on spatial and channel attentions is used or not. |
| 154 | + By default it is True. |
| 155 | + """ |
| 156 | + super(UltraLight_VM_UNet, self).__init__() |
| 157 | + |
| 158 | + input_channels = params['in_chns'] |
| 159 | + num_classes = params['class_num'] |
| 160 | + c_list = params.get('feature_chns', [8, 16, 24, 32, 48, 64]) |
| 161 | + self.bridge = params.get('bridge', True) |
| 162 | + split_att = 'fc' |
| 163 | + # def __init__(self, num_classes=1, input_channels=3, c_list=[8,16,24,32,48,64], |
| 164 | + # split_att='fc', bridge=True): |
| 165 | + # super().__init__() |
| 166 | + # self.bridge = bridge |
| 167 | + |
| 168 | + self.encoder1 = nn.Sequential( |
| 169 | + nn.Conv2d(input_channels, c_list[0], 3, stride=1, padding=1), |
| 170 | + ) |
| 171 | + self.encoder2 =nn.Sequential( |
| 172 | + nn.Conv2d(c_list[0], c_list[1], 3, stride=1, padding=1), |
| 173 | + ) |
| 174 | + self.encoder3 = nn.Sequential( |
| 175 | + nn.Conv2d(c_list[1], c_list[2], 3, stride=1, padding=1), |
| 176 | + ) |
| 177 | + self.encoder4 = nn.Sequential( |
| 178 | + PVMLayer(input_dim=c_list[2], output_dim=c_list[3]) |
| 179 | + ) |
| 180 | + self.encoder5 = nn.Sequential( |
| 181 | + PVMLayer(input_dim=c_list[3], output_dim=c_list[4]) |
| 182 | + ) |
| 183 | + self.encoder6 = nn.Sequential( |
| 184 | + PVMLayer(input_dim=c_list[4], output_dim=c_list[5]) |
| 185 | + ) |
| 186 | + |
| 187 | + if self.bridge: |
| 188 | + self.scab = SC_Att_Bridge(c_list, split_att) |
| 189 | + print('SC_Att_Bridge was used') |
| 190 | + |
| 191 | + self.decoder1 = nn.Sequential( |
| 192 | + PVMLayer(input_dim=c_list[5], output_dim=c_list[4]) |
| 193 | + ) |
| 194 | + self.decoder2 = nn.Sequential( |
| 195 | + PVMLayer(input_dim=c_list[4], output_dim=c_list[3]) |
| 196 | + ) |
| 197 | + self.decoder3 = nn.Sequential( |
| 198 | + PVMLayer(input_dim=c_list[3], output_dim=c_list[2]) |
| 199 | + ) |
| 200 | + self.decoder4 = nn.Sequential( |
| 201 | + nn.Conv2d(c_list[2], c_list[1], 3, stride=1, padding=1), |
| 202 | + ) |
| 203 | + self.decoder5 = nn.Sequential( |
| 204 | + nn.Conv2d(c_list[1], c_list[0], 3, stride=1, padding=1), |
| 205 | + ) |
| 206 | + self.ebn1 = nn.GroupNorm(4, c_list[0]) |
| 207 | + self.ebn2 = nn.GroupNorm(4, c_list[1]) |
| 208 | + self.ebn3 = nn.GroupNorm(4, c_list[2]) |
| 209 | + self.ebn4 = nn.GroupNorm(4, c_list[3]) |
| 210 | + self.ebn5 = nn.GroupNorm(4, c_list[4]) |
| 211 | + self.dbn1 = nn.GroupNorm(4, c_list[4]) |
| 212 | + self.dbn2 = nn.GroupNorm(4, c_list[3]) |
| 213 | + self.dbn3 = nn.GroupNorm(4, c_list[2]) |
| 214 | + self.dbn4 = nn.GroupNorm(4, c_list[1]) |
| 215 | + self.dbn5 = nn.GroupNorm(4, c_list[0]) |
| 216 | + |
| 217 | + self.final = nn.Conv2d(c_list[0], num_classes, kernel_size=1) |
| 218 | + |
| 219 | + self.apply(self._init_weights) |
| 220 | + |
| 221 | + def _init_weights(self, m): |
| 222 | + if isinstance(m, nn.Linear): |
| 223 | + trunc_normal_(m.weight, std=.02) |
| 224 | + if isinstance(m, nn.Linear) and m.bias is not None: |
| 225 | + nn.init.constant_(m.bias, 0) |
| 226 | + elif isinstance(m, nn.Conv1d): |
| 227 | + n = m.kernel_size[0] * m.out_channels |
| 228 | + m.weight.data.normal_(0, math.sqrt(2. / n)) |
| 229 | + elif isinstance(m, nn.Conv2d): |
| 230 | + fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels |
| 231 | + fan_out //= m.groups |
| 232 | + m.weight.data.normal_(0, math.sqrt(2.0 / fan_out)) |
| 233 | + if m.bias is not None: |
| 234 | + m.bias.data.zero_() |
| 235 | + |
| 236 | + def forward(self, x): |
| 237 | + x_shape = list(x.shape) |
| 238 | + if(len(x_shape) == 5): |
| 239 | + [N, C, D, H, W] = x_shape |
| 240 | + new_shape = [N*D, C, H, W] |
| 241 | + x = torch.transpose(x, 1, 2) |
| 242 | + x = torch.reshape(x, new_shape) |
| 243 | + |
| 244 | + out = F.gelu(F.max_pool2d(self.ebn1(self.encoder1(x)),2,2)) |
| 245 | + t1 = out # b, c0, H/2, W/2 |
| 246 | + |
| 247 | + out = F.gelu(F.max_pool2d(self.ebn2(self.encoder2(out)),2,2)) |
| 248 | + t2 = out # b, c1, H/4, W/4 |
| 249 | + |
| 250 | + out = F.gelu(F.max_pool2d(self.ebn3(self.encoder3(out)),2,2)) |
| 251 | + t3 = out # b, c2, H/8, W/8 |
| 252 | + |
| 253 | + out = F.gelu(F.max_pool2d(self.ebn4(self.encoder4(out)),2,2)) |
| 254 | + t4 = out # b, c3, H/16, W/16 |
| 255 | + |
| 256 | + out = F.gelu(F.max_pool2d(self.ebn5(self.encoder5(out)),2,2)) |
| 257 | + t5 = out # b, c4, H/32, W/32 |
| 258 | + |
| 259 | + if self.bridge: t1, t2, t3, t4, t5 = self.scab(t1, t2, t3, t4, t5) |
| 260 | + |
| 261 | + out = F.gelu(self.encoder6(out)) # b, c5, H/32, W/32 |
| 262 | + |
| 263 | + out5 = F.gelu(self.dbn1(self.decoder1(out))) # b, c4, H/32, W/32 |
| 264 | + out5 = torch.add(out5, t5) # b, c4, H/32, W/32 |
| 265 | + |
| 266 | + out4 = F.gelu(F.interpolate(self.dbn2(self.decoder2(out5)),scale_factor=(2,2),mode ='bilinear',align_corners=True)) # b, c3, H/16, W/16 |
| 267 | + out4 = torch.add(out4, t4) # b, c3, H/16, W/16 |
| 268 | + |
| 269 | + out3 = F.gelu(F.interpolate(self.dbn3(self.decoder3(out4)),scale_factor=(2,2),mode ='bilinear',align_corners=True)) # b, c2, H/8, W/8 |
| 270 | + out3 = torch.add(out3, t3) # b, c2, H/8, W/8 |
| 271 | + |
| 272 | + out2 = F.gelu(F.interpolate(self.dbn4(self.decoder4(out3)),scale_factor=(2,2),mode ='bilinear',align_corners=True)) # b, c1, H/4, W/4 |
| 273 | + out2 = torch.add(out2, t2) # b, c1, H/4, W/4 |
| 274 | + |
| 275 | + out1 = F.gelu(F.interpolate(self.dbn5(self.decoder5(out2)),scale_factor=(2,2),mode ='bilinear',align_corners=True)) # b, c0, H/2, W/2 |
| 276 | + out1 = torch.add(out1, t1) # b, c0, H/2, W/2 |
| 277 | + |
| 278 | + out0 = F.interpolate(self.final(out1),scale_factor=(2,2),mode ='bilinear',align_corners=True) # b, num_class, H, W |
| 279 | + |
| 280 | + if(len(x_shape) == 5): |
| 281 | + new_shape = [N, D] + list(out0.shape)[1:] |
| 282 | + out0 = torch.transpose(torch.reshape(out0, new_shape), 1, 2) |
| 283 | + return out0 |
| 284 | + |
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