File size: 7,284 Bytes
dc47947
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
244
245
246
247
248
249
250
import torch

import torch.nn as nn


class Slice(nn.Module):
    def __init__(self, start_index=1):
        super(Slice, self).__init__()
        self.start_index = start_index

    def forward(self, x):
        return x[:, self.start_index:]


class AddReadout(nn.Module):
    def __init__(self, start_index=1):
        super(AddReadout, self).__init__()
        self.start_index = start_index

    def forward(self, x):
        if self.start_index == 2:
            readout = (x[:, 0] + x[:, 1]) / 2
        else:
            readout = x[:, 0]
        return x[:, self.start_index:] + readout.unsqueeze(1)


class ProjectReadout(nn.Module):
    def __init__(self, in_features, start_index=1):
        super(ProjectReadout, self).__init__()
        self.start_index = start_index

        self.project = nn.Sequential(nn.Linear(2 * in_features, in_features), nn.GELU())

    def forward(self, x):
        readout = x[:, 0].unsqueeze(1).expand_as(x[:, self.start_index:])
        features = torch.cat((x[:, self.start_index:], readout), -1)

        return self.project(features)


class Transpose(nn.Module):
    def __init__(self, dim0, dim1):
        super(Transpose, self).__init__()
        self.dim0 = dim0
        self.dim1 = dim1

    def forward(self, x):
        x = x.transpose(self.dim0, self.dim1)
        return x


activations = {}


def get_activation(name):
    def hook(model, input, output):
        activations[name] = output

    return hook


def forward_default(pretrained, x, function_name="forward_features"):
    exec(f"pretrained.model.{function_name}(x)")

    layer_1 = pretrained.activations["1"]
    layer_2 = pretrained.activations["2"]
    layer_3 = pretrained.activations["3"]
    layer_4 = pretrained.activations["4"]

    if hasattr(pretrained, "act_postprocess1"):
        layer_1 = pretrained.act_postprocess1(layer_1)
    if hasattr(pretrained, "act_postprocess2"):
        layer_2 = pretrained.act_postprocess2(layer_2)
    if hasattr(pretrained, "act_postprocess3"):
        layer_3 = pretrained.act_postprocess3(layer_3)
    if hasattr(pretrained, "act_postprocess4"):
        layer_4 = pretrained.act_postprocess4(layer_4)

    return layer_1, layer_2, layer_3, layer_4


def forward_adapted_unflatten(pretrained, x, function_name="forward_features"):
    b, c, h, w = x.shape

    exec(f"glob = pretrained.model.{function_name}(x)")

    layer_1 = pretrained.activations["1"]
    layer_2 = pretrained.activations["2"]
    layer_3 = pretrained.activations["3"]
    layer_4 = pretrained.activations["4"]

    layer_1 = pretrained.act_postprocess1[0:2](layer_1)
    layer_2 = pretrained.act_postprocess2[0:2](layer_2)
    layer_3 = pretrained.act_postprocess3[0:2](layer_3)
    layer_4 = pretrained.act_postprocess4[0:2](layer_4)

    unflatten = nn.Sequential(
        nn.Unflatten(
            2,
            torch.Size(
                [
                    h // pretrained.model.patch_size[1],
                    w // pretrained.model.patch_size[0],
                ]
            ),
        )
    )

    if layer_1.ndim == 3:
        layer_1 = unflatten(layer_1)
    if layer_2.ndim == 3:
        layer_2 = unflatten(layer_2)
    if layer_3.ndim == 3:
        layer_3 = unflatten(layer_3)
    if layer_4.ndim == 3:
        layer_4 = unflatten(layer_4)

    layer_1 = pretrained.act_postprocess1[3: len(pretrained.act_postprocess1)](layer_1)
    layer_2 = pretrained.act_postprocess2[3: len(pretrained.act_postprocess2)](layer_2)
    layer_3 = pretrained.act_postprocess3[3: len(pretrained.act_postprocess3)](layer_3)
    layer_4 = pretrained.act_postprocess4[3: len(pretrained.act_postprocess4)](layer_4)

    return layer_1, layer_2, layer_3, layer_4


def get_readout_oper(vit_features, features, use_readout, start_index=1):
    if use_readout == "ignore":
        readout_oper = [Slice(start_index)] * len(features)
    elif use_readout == "add":
        readout_oper = [AddReadout(start_index)] * len(features)
    elif use_readout == "project":
        readout_oper = [
            ProjectReadout(vit_features, start_index) for out_feat in features
        ]
    else:
        assert (
            False
        ), "wrong operation for readout token, use_readout can be 'ignore', 'add', or 'project'"

    return readout_oper


def make_backbone_default(
        model,
        features=[96, 192, 384, 768],
        size=[384, 384],
        hooks=[2, 5, 8, 11],
        vit_features=768,
        use_readout="ignore",
        start_index=1,
        start_index_readout=1,
):
    pretrained = nn.Module()

    pretrained.model = model
    pretrained.model.blocks[hooks[0]].register_forward_hook(get_activation("1"))
    pretrained.model.blocks[hooks[1]].register_forward_hook(get_activation("2"))
    pretrained.model.blocks[hooks[2]].register_forward_hook(get_activation("3"))
    pretrained.model.blocks[hooks[3]].register_forward_hook(get_activation("4"))

    pretrained.activations = activations

    readout_oper = get_readout_oper(vit_features, features, use_readout, start_index_readout)

    # 32, 48, 136, 384
    pretrained.act_postprocess1 = nn.Sequential(
        readout_oper[0],
        Transpose(1, 2),
        nn.Unflatten(2, torch.Size([size[0] // 16, size[1] // 16])),
        nn.Conv2d(
            in_channels=vit_features,
            out_channels=features[0],
            kernel_size=1,
            stride=1,
            padding=0,
        ),
        nn.ConvTranspose2d(
            in_channels=features[0],
            out_channels=features[0],
            kernel_size=4,
            stride=4,
            padding=0,
            bias=True,
            dilation=1,
            groups=1,
        ),
    )

    pretrained.act_postprocess2 = nn.Sequential(
        readout_oper[1],
        Transpose(1, 2),
        nn.Unflatten(2, torch.Size([size[0] // 16, size[1] // 16])),
        nn.Conv2d(
            in_channels=vit_features,
            out_channels=features[1],
            kernel_size=1,
            stride=1,
            padding=0,
        ),
        nn.ConvTranspose2d(
            in_channels=features[1],
            out_channels=features[1],
            kernel_size=2,
            stride=2,
            padding=0,
            bias=True,
            dilation=1,
            groups=1,
        ),
    )

    pretrained.act_postprocess3 = nn.Sequential(
        readout_oper[2],
        Transpose(1, 2),
        nn.Unflatten(2, torch.Size([size[0] // 16, size[1] // 16])),
        nn.Conv2d(
            in_channels=vit_features,
            out_channels=features[2],
            kernel_size=1,
            stride=1,
            padding=0,
        ),
    )

    pretrained.act_postprocess4 = nn.Sequential(
        readout_oper[3],
        Transpose(1, 2),
        nn.Unflatten(2, torch.Size([size[0] // 16, size[1] // 16])),
        nn.Conv2d(
            in_channels=vit_features,
            out_channels=features[3],
            kernel_size=1,
            stride=1,
            padding=0,
        ),
        nn.Conv2d(
            in_channels=features[3],
            out_channels=features[3],
            kernel_size=3,
            stride=2,
            padding=1,
        ),
    )

    pretrained.model.start_index = start_index
    pretrained.model.patch_size = [16, 16]

    return pretrained