File size: 18,166 Bytes
6d1366a
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
import os
import numpy as np
import torch
import torch.nn as nn
import torch._utils
import torch.nn.functional as F
from .ocr import SpatialOCR_Module, SpatialGather_Module
from .resnetv1b import BasicBlockV1b, BottleneckV1b

relu_inplace = True


class HighResolutionModule(nn.Module):
    def __init__(self, num_branches, blocks, num_blocks, num_inchannels,
                 num_channels, fuse_method,multi_scale_output=True,
                 norm_layer=nn.BatchNorm2d, align_corners=True):
        super(HighResolutionModule, self).__init__()
        self._check_branches(num_branches, num_blocks, num_inchannels, num_channels)

        self.num_inchannels = num_inchannels
        self.fuse_method = fuse_method
        self.num_branches = num_branches
        self.norm_layer = norm_layer
        self.align_corners = align_corners

        self.multi_scale_output = multi_scale_output

        self.branches = self._make_branches(
            num_branches, blocks, num_blocks, num_channels)
        self.fuse_layers = self._make_fuse_layers()
        self.relu = nn.ReLU(inplace=relu_inplace)

    def _check_branches(self, num_branches, num_blocks, num_inchannels, num_channels):
        if num_branches != len(num_blocks):
            error_msg = 'NUM_BRANCHES({}) <> NUM_BLOCKS({})'.format(
                num_branches, len(num_blocks))
            raise ValueError(error_msg)

        if num_branches != len(num_channels):
            error_msg = 'NUM_BRANCHES({}) <> NUM_CHANNELS({})'.format(
                num_branches, len(num_channels))
            raise ValueError(error_msg)

        if num_branches != len(num_inchannels):
            error_msg = 'NUM_BRANCHES({}) <> NUM_INCHANNELS({})'.format(
                num_branches, len(num_inchannels))
            raise ValueError(error_msg)

    def _make_one_branch(self, branch_index, block, num_blocks, num_channels,
                         stride=1):
        downsample = None
        if stride != 1 or \
                self.num_inchannels[branch_index] != num_channels[branch_index] * block.expansion:
            downsample = nn.Sequential(
                nn.Conv2d(self.num_inchannels[branch_index],
                          num_channels[branch_index] * block.expansion,
                          kernel_size=1, stride=stride, bias=False),
                self.norm_layer(num_channels[branch_index] * block.expansion),
            )

        layers = []
        layers.append(block(self.num_inchannels[branch_index],
                            num_channels[branch_index], stride,
                            downsample=downsample, norm_layer=self.norm_layer))
        self.num_inchannels[branch_index] = \
            num_channels[branch_index] * block.expansion
        for i in range(1, num_blocks[branch_index]):
            layers.append(block(self.num_inchannels[branch_index],
                                num_channels[branch_index],
                                norm_layer=self.norm_layer))

        return nn.Sequential(*layers)

    def _make_branches(self, num_branches, block, num_blocks, num_channels):
        branches = []

        for i in range(num_branches):
            branches.append(
                self._make_one_branch(i, block, num_blocks, num_channels))

        return nn.ModuleList(branches)

    def _make_fuse_layers(self):
        if self.num_branches == 1:
            return None

        num_branches = self.num_branches
        num_inchannels = self.num_inchannels
        fuse_layers = []
        for i in range(num_branches if self.multi_scale_output else 1):
            fuse_layer = []
            for j in range(num_branches):
                if j > i:
                    fuse_layer.append(nn.Sequential(
                        nn.Conv2d(in_channels=num_inchannels[j],
                                  out_channels=num_inchannels[i],
                                  kernel_size=1,
                                  bias=False),
                        self.norm_layer(num_inchannels[i])))
                elif j == i:
                    fuse_layer.append(None)
                else:
                    conv3x3s = []
                    for k in range(i - j):
                        if k == i - j - 1:
                            num_outchannels_conv3x3 = num_inchannels[i]
                            conv3x3s.append(nn.Sequential(
                                nn.Conv2d(num_inchannels[j],
                                          num_outchannels_conv3x3,
                                          kernel_size=3, stride=2, padding=1, bias=False),
                                self.norm_layer(num_outchannels_conv3x3)))
                        else:
                            num_outchannels_conv3x3 = num_inchannels[j]
                            conv3x3s.append(nn.Sequential(
                                nn.Conv2d(num_inchannels[j],
                                          num_outchannels_conv3x3,
                                          kernel_size=3, stride=2, padding=1, bias=False),
                                self.norm_layer(num_outchannels_conv3x3),
                                nn.ReLU(inplace=relu_inplace)))
                    fuse_layer.append(nn.Sequential(*conv3x3s))
            fuse_layers.append(nn.ModuleList(fuse_layer))

        return nn.ModuleList(fuse_layers)

    def get_num_inchannels(self):
        return self.num_inchannels

    def forward(self, x):
        if self.num_branches == 1:
            return [self.branches[0](x[0])]

        for i in range(self.num_branches):
            x[i] = self.branches[i](x[i])

        x_fuse = []
        for i in range(len(self.fuse_layers)):
            y = x[0] if i == 0 else self.fuse_layers[i][0](x[0])
            for j in range(1, self.num_branches):
                if i == j:
                    y = y + x[j]
                elif j > i:
                    width_output = x[i].shape[-1]
                    height_output = x[i].shape[-2]
                    y = y + F.interpolate(
                        self.fuse_layers[i][j](x[j]),
                        size=[height_output, width_output],
                        mode='bilinear', align_corners=self.align_corners)
                else:
                    y = y + self.fuse_layers[i][j](x[j])
            x_fuse.append(self.relu(y))

        return x_fuse


class HighResolutionNet(nn.Module):
    def __init__(self, width, num_classes, ocr_width=256, small=False,
                 norm_layer=nn.BatchNorm2d, align_corners=True):
        super(HighResolutionNet, self).__init__()
        self.norm_layer = norm_layer
        self.width = width
        self.ocr_width = ocr_width
        self.align_corners = align_corners

        self.conv1 = nn.Conv2d(3, 64, kernel_size=3, stride=2, padding=1, bias=False)
        self.bn1 = norm_layer(64)
        self.conv2 = nn.Conv2d(64, 64, kernel_size=3, stride=2, padding=1, bias=False)
        self.bn2 = norm_layer(64)
        self.relu = nn.ReLU(inplace=relu_inplace)

        num_blocks = 2 if small else 4

        stage1_num_channels = 64
        self.layer1 = self._make_layer(BottleneckV1b, 64, stage1_num_channels, blocks=num_blocks)
        stage1_out_channel = BottleneckV1b.expansion * stage1_num_channels

        self.stage2_num_branches = 2
        num_channels = [width, 2 * width]
        num_inchannels = [
            num_channels[i] * BasicBlockV1b.expansion for i in range(len(num_channels))]
        self.transition1 = self._make_transition_layer(
            [stage1_out_channel], num_inchannels)
        self.stage2, pre_stage_channels = self._make_stage(
            BasicBlockV1b, num_inchannels=num_inchannels, num_modules=1, num_branches=self.stage2_num_branches,
            num_blocks=2 * [num_blocks], num_channels=num_channels)

        self.stage3_num_branches = 3
        num_channels = [width, 2 * width, 4 * width]
        num_inchannels = [
            num_channels[i] * BasicBlockV1b.expansion for i in range(len(num_channels))]
        self.transition2 = self._make_transition_layer(
            pre_stage_channels, num_inchannels)
        self.stage3, pre_stage_channels = self._make_stage(
            BasicBlockV1b, num_inchannels=num_inchannels,
            num_modules=3 if small else 4, num_branches=self.stage3_num_branches,
            num_blocks=3 * [num_blocks], num_channels=num_channels)

        self.stage4_num_branches = 4
        num_channels = [width, 2 * width, 4 * width, 8 * width]
        num_inchannels = [
            num_channels[i] * BasicBlockV1b.expansion for i in range(len(num_channels))]
        self.transition3 = self._make_transition_layer(
            pre_stage_channels, num_inchannels)
        self.stage4, pre_stage_channels = self._make_stage(
            BasicBlockV1b, num_inchannels=num_inchannels, num_modules=2 if small else 3,
            num_branches=self.stage4_num_branches,
            num_blocks=4 * [num_blocks], num_channels=num_channels)

        last_inp_channels = np.int(np.sum(pre_stage_channels))
        if self.ocr_width > 0:
            ocr_mid_channels = 2 * self.ocr_width
            ocr_key_channels = self.ocr_width

            self.conv3x3_ocr = nn.Sequential(
                nn.Conv2d(last_inp_channels, ocr_mid_channels,
                          kernel_size=3, stride=1, padding=1),
                norm_layer(ocr_mid_channels),
                nn.ReLU(inplace=relu_inplace),
            )
            self.ocr_gather_head = SpatialGather_Module(num_classes)

            self.ocr_distri_head = SpatialOCR_Module(in_channels=ocr_mid_channels,
                                                     key_channels=ocr_key_channels,
                                                     out_channels=ocr_mid_channels,
                                                     scale=1,
                                                     dropout=0.05,
                                                     norm_layer=norm_layer,
                                                     align_corners=align_corners)
            self.cls_head = nn.Conv2d(
                ocr_mid_channels, num_classes, kernel_size=1, stride=1, padding=0, bias=True)

            self.aux_head = nn.Sequential(
                nn.Conv2d(last_inp_channels, last_inp_channels,
                          kernel_size=1, stride=1, padding=0),
                norm_layer(last_inp_channels),
                nn.ReLU(inplace=relu_inplace),
                nn.Conv2d(last_inp_channels, num_classes,
                          kernel_size=1, stride=1, padding=0, bias=True)
            )
        else:
            self.cls_head = nn.Sequential(
                nn.Conv2d(last_inp_channels, last_inp_channels,
                          kernel_size=3, stride=1, padding=1),
                norm_layer(last_inp_channels),
                nn.ReLU(inplace=relu_inplace),
                nn.Conv2d(last_inp_channels, num_classes,
                          kernel_size=1, stride=1, padding=0, bias=True)
            )

    def _make_transition_layer(
            self, num_channels_pre_layer, num_channels_cur_layer):
        num_branches_cur = len(num_channels_cur_layer)
        num_branches_pre = len(num_channels_pre_layer)

        transition_layers = []
        for i in range(num_branches_cur):
            if i < num_branches_pre:
                if num_channels_cur_layer[i] != num_channels_pre_layer[i]:
                    transition_layers.append(nn.Sequential(
                        nn.Conv2d(num_channels_pre_layer[i],
                                  num_channels_cur_layer[i],
                                  kernel_size=3,
                                  stride=1,
                                  padding=1,
                                  bias=False),
                        self.norm_layer(num_channels_cur_layer[i]),
                        nn.ReLU(inplace=relu_inplace)))
                else:
                    transition_layers.append(None)
            else:
                conv3x3s = []
                for j in range(i + 1 - num_branches_pre):
                    inchannels = num_channels_pre_layer[-1]
                    outchannels = num_channels_cur_layer[i] \
                        if j == i - num_branches_pre else inchannels
                    conv3x3s.append(nn.Sequential(
                        nn.Conv2d(inchannels, outchannels,
                                  kernel_size=3, stride=2, padding=1, bias=False),
                        self.norm_layer(outchannels),
                        nn.ReLU(inplace=relu_inplace)))
                transition_layers.append(nn.Sequential(*conv3x3s))

        return nn.ModuleList(transition_layers)

    def _make_layer(self, block, inplanes, planes, blocks, stride=1):
        downsample = None
        if stride != 1 or inplanes != planes * block.expansion:
            downsample = nn.Sequential(
                nn.Conv2d(inplanes, planes * block.expansion,
                          kernel_size=1, stride=stride, bias=False),
                self.norm_layer(planes * block.expansion),
            )

        layers = []
        layers.append(block(inplanes, planes, stride,
                            downsample=downsample, norm_layer=self.norm_layer))
        inplanes = planes * block.expansion
        for i in range(1, blocks):
            layers.append(block(inplanes, planes, norm_layer=self.norm_layer))

        return nn.Sequential(*layers)

    def _make_stage(self, block, num_inchannels,
                    num_modules, num_branches, num_blocks, num_channels,
                    fuse_method='SUM',
                    multi_scale_output=True):
        modules = []
        for i in range(num_modules):
            # multi_scale_output is only used last module
            if not multi_scale_output and i == num_modules - 1:
                reset_multi_scale_output = False
            else:
                reset_multi_scale_output = True
            modules.append(
                HighResolutionModule(num_branches,
                                     block,
                                     num_blocks,
                                     num_inchannels,
                                     num_channels,
                                     fuse_method,
                                     reset_multi_scale_output,
                                     norm_layer=self.norm_layer,
                                     align_corners=self.align_corners)
            )
            num_inchannels = modules[-1].get_num_inchannels()

        return nn.Sequential(*modules), num_inchannels

    def forward(self, x, additional_features=None):
        feats = self.compute_hrnet_feats(x, additional_features)
        if self.ocr_width > 0:
            out_aux = self.aux_head(feats)
            feats = self.conv3x3_ocr(feats)

            context = self.ocr_gather_head(feats, out_aux)
            feats = self.ocr_distri_head(feats, context)
            out = self.cls_head(feats)
            return [out, out_aux]
        else:
            return [self.cls_head(feats), None]

    def compute_hrnet_feats(self, x, additional_features):
        x = self.compute_pre_stage_features(x, additional_features)
        x = self.layer1(x)

        x_list = []
        for i in range(self.stage2_num_branches):
            if self.transition1[i] is not None:
                x_list.append(self.transition1[i](x))
            else:
                x_list.append(x)
        y_list = self.stage2(x_list)

        x_list = []
        for i in range(self.stage3_num_branches):
            if self.transition2[i] is not None:
                if i < self.stage2_num_branches:
                    x_list.append(self.transition2[i](y_list[i]))
                else:
                    x_list.append(self.transition2[i](y_list[-1]))
            else:
                x_list.append(y_list[i])
        y_list = self.stage3(x_list)

        x_list = []
        for i in range(self.stage4_num_branches):
            if self.transition3[i] is not None:
                if i < self.stage3_num_branches:
                    x_list.append(self.transition3[i](y_list[i]))
                else:
                    x_list.append(self.transition3[i](y_list[-1]))
            else:
                x_list.append(y_list[i])
        x = self.stage4(x_list)

        return self.aggregate_hrnet_features(x)

    def compute_pre_stage_features(self, x, additional_features):
        x = self.conv1(x)
        x = self.bn1(x)
        x = self.relu(x)
        if additional_features is not None:
            x = x + additional_features
        x = self.conv2(x)
        x = self.bn2(x)
        return self.relu(x)

    def aggregate_hrnet_features(self, x):
        # Upsampling
        x0_h, x0_w = x[0].size(2), x[0].size(3)
        x1 = F.interpolate(x[1], size=(x0_h, x0_w),
                           mode='bilinear', align_corners=self.align_corners)
        x2 = F.interpolate(x[2], size=(x0_h, x0_w),
                           mode='bilinear', align_corners=self.align_corners)
        x3 = F.interpolate(x[3], size=(x0_h, x0_w),
                           mode='bilinear', align_corners=self.align_corners)

        return torch.cat([x[0], x1, x2, x3], 1)

    def load_pretrained_weights(self, pretrained_path=''):
        model_dict = self.state_dict()

        if not os.path.exists(pretrained_path):
            print(f'\nFile "{pretrained_path}" does not exist.')
            print('You need to specify the correct path to the pre-trained weights.\n'
                  'You can download the weights for HRNet from the repository:\n'
                  'https://github.com/HRNet/HRNet-Image-Classification')
            exit(1)
        pretrained_dict = torch.load(pretrained_path, map_location={'cuda:0': 'cpu'})
        pretrained_dict = {k.replace('last_layer', 'aux_head').replace('model.', ''): v for k, v in
                           pretrained_dict.items()}

        pretrained_dict = {k: v for k, v in pretrained_dict.items()
                           if k in model_dict.keys()}

        model_dict.update(pretrained_dict)
        self.load_state_dict(model_dict)