File size: 13,855 Bytes
fe6c2e4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import torch
from torch import nn
import torch.nn.functional as F
import math

### --- Positional encoding--- ###
### --- Borrowed from Detr--- ###
class PositionEncodingSine2D(nn.Module):
    """
    This is a more standard version of the position embedding, very similar to the one
    used by the Attention is all you need paper, generalized to work on images.
    """
    def __init__(self, num_pos_feats=64, temperature=10000, normalize=True, scale=None):
        super(PositionEncodingSine2D, self).__init__()
        self.num_pos_feats = num_pos_feats
        self.temperature = temperature
        self.normalize = normalize
        if scale is not None and normalize is False:
            raise ValueError("normalize should be True if scale is passed")
        if scale is None:
            scale = 2 * math.pi
        self.scale = scale

    def forward(self, x, isTarget = False):
        '''
        input x: B, C, H, W
        return pos: B, C, H, W
        
        '''
        not_mask = torch.ones(x.size()[0], x.size()[2], x.size()[3]).to(x.device)
        y_embed = not_mask.cumsum(1, dtype=torch.float32)
        x_embed = not_mask.cumsum(2, dtype=torch.float32)
        
        if self.normalize:
            eps = 1e-6
            ## no diff between source and target
            y_embed = y_embed / (y_embed[:, -1:, :] + eps) * self.scale
            x_embed = x_embed / (x_embed[:, :, -1:] + eps) * self.scale

        dim_t = torch.arange(self.num_pos_feats, dtype=torch.float32, device=x.device)
        dim_t = self.temperature ** (2 * (dim_t // 2) / self.num_pos_feats)

        pos_x = x_embed[:, :, :, None] / dim_t
        pos_y = y_embed[:, :, :, None] / dim_t
        pos_x = torch.stack((pos_x[:, :, :, 0::2].sin(), pos_x[:, :, :, 1::2].cos()), dim=4).flatten(3)
        pos_y = torch.stack((pos_y[:, :, :, 0::2].sin(), pos_y[:, :, :, 1::2].cos()), dim=4).flatten(3)
        pos = torch.cat((pos_y, pos_x), dim=3).permute(0, 3, 1, 2)
        return pos

class EncoderLayerInnerAttention(nn.Module):
    """
    Transformer encoder with all paramters
    """
    def __init__(self, d_model, nhead, dim_feedforward, dropout, activation, pos_weight, feat_weight):
        super(EncoderLayerInnerAttention, self).__init__()
        
        
        self.pos_weight = pos_weight
        self.feat_weight = feat_weight
        self.inner_encoder_layer = nn.TransformerEncoderLayer(d_model=d_model, nhead=nhead, dim_feedforward=dim_feedforward, dropout=dropout, activation = activation)
        self.posEncoder = PositionEncodingSine2D(d_model // 2)
        
        self.cross_encoder_layer = EncoderLayerCrossAttention(d_model=d_model, nhead=nhead, dim_feedforward=dim_feedforward,
                                                                dropout=dropout, activation=activation)
        
    def forward(self, x, y, featmask, x_mask = None, y_mask = None):
        '''
        input x: B, C, H, W
        input y: B, C, H, W
        input x_mask: B, 1, H, W, mask == True will be ignored
        input y_mask: B, 1, H, W, mask == True will be ignored
        '''
        
        # do cross attention on x and featmask
        x = self.cross_encoder_layer(x, featmask, None)[0]

        bx, cx, hx, wx = x.size()
        
        by, cy, hy, wy = y.size()
        
        posx = self.posEncoder(x)
        posy = self.posEncoder(y)
        
        
        featx = self.feat_weight * x + self.pos_weight * posx
        featy = self.feat_weight * y + self.pos_weight * posy
        
        
        ## input of transformer should be : seq_len * batch_size * feat_dim 
        featx = featx.flatten(2).permute(2, 0, 1) 
        featy = featy.flatten(2).permute(2, 0, 1)
        x_mask = x_mask.flatten(2).squeeze(1) if x_mask is not None else torch.cuda.BoolTensor(bx, hx * wx).fill_(False)
        y_mask = y_mask.flatten(2).squeeze(1) if y_mask is not None else torch.cuda.BoolTensor(by, hy * wy).fill_(False)
        
        ## input of transformer: (seq_len*2) * batch_size * feat_dim
        len_seq_x, len_seq_y = featx.size()[0], featy.size()[0]
        
        output = torch.cat([featx, featy], dim=0)
        src_key_padding_mask = torch.cat((x_mask, y_mask), dim=1)
        with torch.no_grad() : 
            src_mask = torch.cuda.BoolTensor(hx * wx + hy * wy, hx * wx + hy * wy).fill_(True)
            src_mask[:hx * wx, :hx * wx] = False
            src_mask[hx * wx :, hx * wx:] = False
        
        output = self.inner_encoder_layer(output, src_mask=src_mask, src_key_padding_mask=src_key_padding_mask)

        outx, outy = output.narrow(0, 0, len_seq_x), output.narrow(0, len_seq_x, len_seq_y)  
        outx, outy = outx.permute(1, 2, 0).view(bx, cx, hx, wx), outy.permute(1, 2, 0).view(by, cy, hy, wy)
        x_mask, y_mask = x_mask.view(bx, 1, hx, wx), y_mask.view(bx, 1, hy, wy)
        
        return  outx, outy, x_mask, y_mask
    
class EncoderLayerCrossAttention(nn.Module):
    """
    Transformer encoder with all paramters
    """
    def __init__(self, d_model, nhead, dim_feedforward, dropout, activation):
        super(EncoderLayerCrossAttention, self).__init__()
        
        self.cross_encoder_layer = nn.TransformerEncoderLayer(d_model=d_model, nhead=nhead, dim_feedforward=dim_feedforward, dropout=dropout, activation = activation)
        
    def forward(self, featx, featy, featmask, x_mask = None, y_mask = None):
        '''
        input x: B, C, H, W
        input y: B, C, H, W
        input x_mask: B, 1, H, W, mask == True will be ignored
        input y_mask: B, 1, H, W, mask == True will be ignored
        '''
        
        bx, cx, hx, wx = featx.size()
        by, cy, hy, wy = featy.size()
        
        ## input of transformer should be : seq_len * batch_size * feat_dim 
        featx = featx.flatten(2).permute(2, 0, 1) 
        featy = featy.flatten(2).permute(2, 0, 1)
        x_mask = x_mask.flatten(2).squeeze(1) if x_mask is not None else torch.cuda.BoolTensor(bx, hx * wx).fill_(False)
        y_mask = y_mask.flatten(2).squeeze(1) if y_mask is not None else torch.cuda.BoolTensor(by, hy * wy).fill_(False)
        
        ## input of transformer: (seq_len*2) * batch_size * feat_dim
        len_seq_x, len_seq_y = featx.size()[0], featy.size()[0]
        
        output = torch.cat([featx, featy], dim=0)
        src_key_padding_mask = torch.cat((x_mask, y_mask), dim=1)
        with torch.no_grad() : 
            src_mask = torch.cuda.BoolTensor(hx * wx + hy * wy, hx * wx + hy * wy).fill_(False)
            src_mask[:hx * wx, :hx * wx] = True
            src_mask[hx * wx :, hx * wx:] = True
            
        output = self.cross_encoder_layer(output, src_mask=src_mask, src_key_padding_mask=src_key_padding_mask)
        
        outx, outy = output.narrow(0, 0, len_seq_x), output.narrow(0, len_seq_x, len_seq_y)  
        outx, outy = outx.permute(1, 2, 0).view(bx, cx, hx, wx), outy.permute(1, 2, 0).view(by, cy, hy, wy)
        x_mask, y_mask = x_mask.view(bx, 1, hx, wx), y_mask.view(bx, 1, hy, wy)
        
        return  outx, outy, x_mask, y_mask
    
class EncoderLayerEmpty(nn.Module):
    """
    Transformer encoder with all paramters
    """
    def __init__(self):
        super(EncoderLayerEmpty, self).__init__()
        
    def forward(self, featx, featy, featmask, x_mask = None, y_mask = None):
        '''
        input x: B, C, H, W
        input y: B, C, H, W
        input x_mask: B, 1, H, W, mask == True will be ignored
        input y_mask: B, 1, H, W, mask == True will be ignored
        '''
        return  featx, featy, x_mask, y_mask
    
class EncoderLayerBlock(nn.Module):
    """
    Transformer encoder with all paramters
    """
    def __init__(self, d_model, nhead, dim_feedforward, dropout, activation, pos_weight, feat_weight, layer_type) :
        super(EncoderLayerBlock, self).__init__()
        
        cross_encoder_layer = EncoderLayerCrossAttention(d_model, nhead, dim_feedforward, dropout, activation)
        att_encoder_layer = EncoderLayerInnerAttention(d_model, nhead, dim_feedforward, dropout, activation, pos_weight, feat_weight)
        
        if layer_type[0] == 'C' :
            self.layer1 = cross_encoder_layer 
        elif layer_type[0] == 'I' :
            self.layer1 = att_encoder_layer 
        elif layer_type[0] == 'N' :
            self.layer1 = EncoderLayerEmpty()
        
        if layer_type[1] == 'C' :
            self.layer2 = cross_encoder_layer 
        elif layer_type[1] == 'I' :
            self.layer2 = att_encoder_layer 
        elif layer_type[1] == 'N' :
            self.layer2 = EncoderLayerEmpty()

    def forward(self, featx, featy, featmask, x_mask = None, y_mask = None):
        '''
        input x: B, C, H, W
        input y: B, C, H, W
        input x_mask: B, 1, H, W, mask == True will be ignored
        input y_mask: B, 1, H, W, mask == True will be ignored
        '''
        
        featx, featy, x_mask, y_mask = self.layer1(featx, featy, featmask, x_mask, y_mask)
        featx, featy, x_mask, y_mask = self.layer2(featx, featy, featmask, x_mask, y_mask)

        return  featx, featy, x_mask, y_mask
    
### --- Transformer Encoder --- ###
class Decoder(nn.Module):

    def __init__(self, in_channels=256, out_channels=3):
        super(Decoder, self).__init__()

        self.deconv1 = nn.ConvTranspose2d(in_channels, 128, 2, stride=2) # 60
        self.relu1 = nn.ReLU()

        self.deconv2 = nn.ConvTranspose2d(128, out_channels, 2, stride=2) # 120

    def forward(self, x):

        x = self.deconv1(x)
        x = self.relu1(x)

        x = self.deconv2(x)

        x = F.interpolate(x, scale_factor=4, mode='bilinear', align_corners=False)

        return x
    
class ClsBranch(nn.Module):
    # branch to predict if the object exists or not.
    def __init__(self, in_dim):
        super(ClsBranch, self).__init__()

        self.conv = nn.Conv2d(in_dim, 1, 3)
        self.relu = nn.ReLU()

        self.mlp = nn.Sequential(*[nn.Linear(28*28, 32), 
                                    nn.ReLU(), 
                                    nn.Linear(32, 1), 
                                    nn.Sigmoid()])
        
    def forward(self, x):

        x = self.conv(x)
        x = self.relu(x)
        x = torch.flatten(x, start_dim=1)
        x = self.mlp(x)
        return x
        
class Encoder(nn.Module):
    """
    Transformer encoder with all paramters
    """
    def __init__(self, feat_dim, pos_weight = 0.1, feat_weight=1, d_model=512, nhead=8, num_layers=6, dim_feedforward=2048, dropout=0.1, activation='relu', layer_type = ['I', 'C', 'I', 'C', 'I', 'C'], drop_feat = 0.1):
        super(Encoder, self).__init__()
        
        self.num_layers = num_layers
        self.feat_proj = nn.Conv2d(feat_dim, d_model, kernel_size=1)
        self.drop_feat = nn.Dropout2d(p=drop_feat)
        self.encoder_blocks = nn.ModuleList([EncoderLayerBlock(d_model, nhead, dim_feedforward, dropout, activation, pos_weight, feat_weight, layer_type[i * 2 : i * 2 + 2]) for i in range(num_layers)])

        self.decoder = Decoder(d_model, 3)
        self.cls_branch = ClsBranch(in_dim=256)
        self.sigmoid = nn.Sigmoid()
        self.eps = 1e-7
        
        
    def forward(self, x, y, fmask, x_mask = None, y_mask = None):
        '''
        input x: B, C, H, W
        input y: B, C, H, W
        input x_mask: B, 1, H, W, mask == True will be ignored
        input y_mask: B, 1, H, W, mask == True will be ignored
        '''
        featx = self.feat_proj (x)
        featx = self.drop_feat(featx)
        
        bx, cx, hx, wx = featx.size()
        
        featy = self.feat_proj (y)
        featy = self.drop_feat(featy)
        
        by, cy, hy, wy = featy.size()

        featmask = self.feat_proj(fmask)

        for i in range(self.num_layers) : 
            featx, featy, x_mask, y_mask = self.encoder_blocks[i](featx, featy, featmask, x_mask, y_mask)
        
        out_cls = self.cls_branch(featy)
        outx = self.sigmoid(self.decoder(featx))
        outy = self.sigmoid(self.decoder(featy))

        outx = torch.clamp(outx, min=self.eps, max=1-self.eps)
        outy = torch.clamp(outy, min=self.eps, max=1-self.eps)
        
        return  outx, outy, out_cls
    
### --- Transformer Encoder --- ###
class TransEncoder(nn.Module):
    """
    Transformer encoder: small and large variants
    """
    def __init__(self, feat_dim=1024, pos_weight = 0.1, feat_weight = 1, dropout=0.1, activation='relu', mode='small', layer_type=['I', 'C', 'I', 'C', 'I', 'N'], drop_feat=0.1):
        super(TransEncoder, self).__init__()
        
        if mode == 'tiny' : 
            d_model=128
            nhead=2
            num_layers=3
            dim_feedforward=256
            
        elif mode == 'small' : 
            d_model=256
            nhead=2
            num_layers=3
            dim_feedforward=256
            
        elif mode == 'base' : 
            d_model=512
            nhead=8
            num_layers=3
            dim_feedforward=2048
            
        elif mode == 'large' : 
            d_model=512
            nhead=8
            num_layers=6
            dim_feedforward=2048
            
        self.net = Encoder(feat_dim, pos_weight, feat_weight, d_model, nhead, num_layers, dim_feedforward, dropout, activation, layer_type, drop_feat)
        
    def forward(self, x, y, fmask, x_mask = None, y_mask = None):
        '''
        input x: B, C, H, W
        input y: B, C, H, W
        
        '''
        outx, outy, out_cls = self.net(x, y, fmask, x_mask, y_mask)

        return  outx, outy, out_cls
    
if __name__ == '__main__' : 
    
    feat_dim = 256
    mode = 'small'
    x = torch.cuda.FloatTensor(2, feat_dim, 10, 10)
    x_mask = torch.cuda.BoolTensor(2, 1, 10, 10)
    
    net = TransEncoder()
    
    print (net)