File size: 9,024 Bytes
853e22b
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright (c) MONAI Consortium
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#     http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

import torch
import torch.nn as nn
import torch.nn.functional as F

from monai.networks.blocks.convolutions import Convolution
from monai.networks.blocks.upsample import UpSample
from monai.networks.layers.factories import Act, Conv, Norm
from monai.utils import optional_import

models, _ = optional_import("torchvision", name="models")


class GCN(nn.Module):
    """
    The Global Convolutional Network module using large 1D
    Kx1 and 1xK kernels to represent 2D kernels.
    """

    def __init__(self, inplanes: int, planes: int, ks: int = 7):
        """
        Args:
            inplanes: number of input channels.
            planes: number of output channels.
            ks: kernel size for one dimension. Defaults to 7.
        """
        super().__init__()

        conv2d_type: type[nn.Conv2d] = Conv[Conv.CONV, 2]
        self.conv_l1 = conv2d_type(in_channels=inplanes, out_channels=planes, kernel_size=(ks, 1), padding=(ks // 2, 0))
        self.conv_l2 = conv2d_type(in_channels=planes, out_channels=planes, kernel_size=(1, ks), padding=(0, ks // 2))
        self.conv_r1 = conv2d_type(in_channels=inplanes, out_channels=planes, kernel_size=(1, ks), padding=(0, ks // 2))
        self.conv_r2 = conv2d_type(in_channels=planes, out_channels=planes, kernel_size=(ks, 1), padding=(ks // 2, 0))

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        """
        Args:
            x: in shape (batch, inplanes, spatial_1, spatial_2).
        """
        x_l = self.conv_l1(x)
        x_l = self.conv_l2(x_l)
        x_r = self.conv_r1(x)
        x_r = self.conv_r2(x_r)
        x = x_l + x_r
        return x


class Refine(nn.Module):
    """
    Simple residual block to refine the details of the activation maps.
    """

    def __init__(self, planes: int):
        """
        Args:
            planes: number of input channels.
        """
        super().__init__()

        relu_type: type[nn.ReLU] = Act[Act.RELU]
        conv2d_type: type[nn.Conv2d] = Conv[Conv.CONV, 2]
        norm2d_type: type[nn.BatchNorm2d] = Norm[Norm.BATCH, 2]

        self.bn = norm2d_type(num_features=planes)
        self.relu = relu_type(inplace=True)
        self.conv1 = conv2d_type(in_channels=planes, out_channels=planes, kernel_size=3, padding=1)
        self.conv2 = conv2d_type(in_channels=planes, out_channels=planes, kernel_size=3, padding=1)

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        """
        Args:
            x: in shape (batch, planes, spatial_1, spatial_2).
        """
        residual = x
        x = self.bn(x)
        x = self.relu(x)
        x = self.conv1(x)
        x = self.bn(x)
        x = self.relu(x)
        x = self.conv2(x)

        return residual + x


class FCN(nn.Module):
    """
    2D FCN network with 3 input channels. The small decoder is built
    with the GCN and Refine modules.
    The code is adapted from `lsqshr's official 2D code <https://github.com/lsqshr/AH-Net/blob/master/net2d.py>`_.

    Args:
        out_channels: number of output channels. Defaults to 1.
        upsample_mode: [``"transpose"``, ``"bilinear"``]
            The mode of upsampling manipulations.
            Using the second mode cannot guarantee the model's reproducibility. Defaults to ``bilinear``.

            - ``transpose``, uses transposed convolution layers.
            - ``bilinear``, uses bilinear interpolation.

        pretrained: If True, returns a model pre-trained on ImageNet
        progress: If True, displays a progress bar of the download to stderr.
    """

    def __init__(
        self, out_channels: int = 1, upsample_mode: str = "bilinear", pretrained: bool = True, progress: bool = True
    ):
        super().__init__()

        conv2d_type: type[nn.Conv2d] = Conv[Conv.CONV, 2]

        self.upsample_mode = upsample_mode
        self.conv2d_type = conv2d_type
        self.out_channels = out_channels
        resnet = models.resnet50(pretrained=pretrained, progress=progress)

        self.conv1 = resnet.conv1
        self.bn0 = resnet.bn1
        self.relu = resnet.relu
        self.maxpool = resnet.maxpool

        self.layer1 = resnet.layer1
        self.layer2 = resnet.layer2
        self.layer3 = resnet.layer3
        self.layer4 = resnet.layer4

        self.gcn1 = GCN(2048, self.out_channels)
        self.gcn2 = GCN(1024, self.out_channels)
        self.gcn3 = GCN(512, self.out_channels)
        self.gcn4 = GCN(64, self.out_channels)
        self.gcn5 = GCN(64, self.out_channels)

        self.refine1 = Refine(self.out_channels)
        self.refine2 = Refine(self.out_channels)
        self.refine3 = Refine(self.out_channels)
        self.refine4 = Refine(self.out_channels)
        self.refine5 = Refine(self.out_channels)
        self.refine6 = Refine(self.out_channels)
        self.refine7 = Refine(self.out_channels)
        self.refine8 = Refine(self.out_channels)
        self.refine9 = Refine(self.out_channels)
        self.refine10 = Refine(self.out_channels)
        self.transformer = self.conv2d_type(in_channels=256, out_channels=64, kernel_size=1)

        if self.upsample_mode == "transpose":
            self.up_conv = UpSample(spatial_dims=2, in_channels=self.out_channels, scale_factor=2, mode="deconv")

    def forward(self, x: torch.Tensor):
        """
        Args:
            x: in shape (batch, 3, spatial_1, spatial_2).
        """
        org_input = x
        x = self.conv1(x)
        x = self.bn0(x)
        x = self.relu(x)
        conv_x = x
        x = self.maxpool(x)
        pool_x = x

        fm1 = self.layer1(x)
        fm2 = self.layer2(fm1)
        fm3 = self.layer3(fm2)
        fm4 = self.layer4(fm3)

        gcfm1 = self.refine1(self.gcn1(fm4))
        gcfm2 = self.refine2(self.gcn2(fm3))
        gcfm3 = self.refine3(self.gcn3(fm2))
        gcfm4 = self.refine4(self.gcn4(pool_x))
        gcfm5 = self.refine5(self.gcn5(conv_x))

        if self.upsample_mode == "transpose":
            fs1 = self.refine6(self.up_conv(gcfm1) + gcfm2)
            fs2 = self.refine7(self.up_conv(fs1) + gcfm3)
            fs3 = self.refine8(self.up_conv(fs2) + gcfm4)
            fs4 = self.refine9(self.up_conv(fs3) + gcfm5)
            return self.refine10(self.up_conv(fs4))
        fs1 = self.refine6(F.interpolate(gcfm1, fm3.size()[2:], mode=self.upsample_mode, align_corners=True) + gcfm2)
        fs2 = self.refine7(F.interpolate(fs1, fm2.size()[2:], mode=self.upsample_mode, align_corners=True) + gcfm3)
        fs3 = self.refine8(F.interpolate(fs2, pool_x.size()[2:], mode=self.upsample_mode, align_corners=True) + gcfm4)
        fs4 = self.refine9(F.interpolate(fs3, conv_x.size()[2:], mode=self.upsample_mode, align_corners=True) + gcfm5)
        return self.refine10(F.interpolate(fs4, org_input.size()[2:], mode=self.upsample_mode, align_corners=True))


class MCFCN(FCN):
    """
    The multi-channel version of the 2D FCN module.
    Adds a projection layer to take arbitrary number of inputs.

    Args:
        in_channels: number of input channels. Defaults to 3.
        out_channels: number of output channels. Defaults to 1.
        upsample_mode: [``"transpose"``, ``"bilinear"``]
            The mode of upsampling manipulations.
            Using the second mode cannot guarantee the model's reproducibility. Defaults to ``bilinear``.

            - ``transpose``, uses transposed convolution layers.
            - ``bilinear``, uses bilinear interpolate.
        pretrained: If True, returns a model pre-trained on ImageNet
        progress: If True, displays a progress bar of the download to stderr.
    """

    def __init__(
        self,
        in_channels: int = 3,
        out_channels: int = 1,
        upsample_mode: str = "bilinear",
        pretrained: bool = True,
        progress: bool = True,
    ):
        super().__init__(
            out_channels=out_channels, upsample_mode=upsample_mode, pretrained=pretrained, progress=progress
        )

        self.init_proj = Convolution(
            spatial_dims=2,
            in_channels=in_channels,
            out_channels=3,
            kernel_size=1,
            act=("relu", {"inplace": True}),
            norm=Norm.BATCH,
            bias=False,
        )

    def forward(self, x: torch.Tensor):
        """
        Args:
            x: in shape (batch, in_channels, spatial_1, spatial_2).
        """
        x = self.init_proj(x)
        return super().forward(x)