File size: 9,897 Bytes
2252f3d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import torch.nn as nn
from .net_utils import PosEnSine, softmax_attention, dotproduct_attention, long_range_attention, \
                                   short_range_attention, patch_attention


class OurMultiheadAttention(nn.Module):
    def __init__(self, q_feat_dim, k_feat_dim, out_feat_dim, n_head, d_k=None, d_v=None):
        super(OurMultiheadAttention, self).__init__()
        if d_k is None:
            d_k = out_feat_dim // n_head
        if d_v is None:
            d_v = out_feat_dim // n_head

        self.n_head = n_head
        self.d_k = d_k
        self.d_v = d_v

        # pre-attention projection
        self.w_qs = nn.Conv2d(q_feat_dim, n_head * d_k, 1, bias=False)
        self.w_ks = nn.Conv2d(k_feat_dim, n_head * d_k, 1, bias=False)
        self.w_vs = nn.Conv2d(out_feat_dim, n_head * d_v, 1, bias=False)

        # after-attention combine heads
        self.fc = nn.Conv2d(n_head * d_v, out_feat_dim, 1, bias=False)

    def forward(self, q, k, v, attn_type='softmax', **kwargs):
        # input: b x d x h x w
        d_k, d_v, n_head = self.d_k, self.d_v, self.n_head

        # Pass through the pre-attention projection: b x (nhead*dk) x h x w
        # Separate different heads: b x nhead x dk x h x w
        q = self.w_qs(q).view(q.shape[0], n_head, d_k, q.shape[2], q.shape[3])
        k = self.w_ks(k).view(k.shape[0], n_head, d_k, k.shape[2], k.shape[3])
        v = self.w_vs(v).view(v.shape[0], n_head, d_v, v.shape[2], v.shape[3])

        # -------------- Attention -----------------
        if attn_type == 'softmax':
            q, attn = softmax_attention(q, k, v)    # b x n x dk x h x w --> b x n x dv x h x w
        elif attn_type == 'dotproduct':
            q, attn = dotproduct_attention(q, k, v)
        elif attn_type == 'patch':
            q, attn = patch_attention(q, k, v, P=kwargs['P'])
        elif attn_type == 'sparse_long':
            q, attn = long_range_attention(q, k, v, P_h=kwargs['ah'], P_w=kwargs['aw'])
        elif attn_type == 'sparse_short':
            q, attn = short_range_attention(q, k, v, Q_h=kwargs['ah'], Q_w=kwargs['aw'])
        else:
            raise NotImplementedError(f'Unknown attention type {attn_type}')
        # ------------ end Attention ---------------

        # Concatenate all the heads together: b x (n*dv) x h x w
        q = q.reshape(q.shape[0], -1, q.shape[3], q.shape[4])
        q = self.fc(q)    # b x d x h x w

        return q, attn


class TransformerEncoderUnit(nn.Module):
    def __init__(self, feat_dim, n_head=8, pos_en_flag=True, attn_type='softmax', P=None):
        super(TransformerEncoderUnit, self).__init__()
        self.feat_dim = feat_dim
        self.attn_type = attn_type
        self.pos_en_flag = pos_en_flag
        self.P = P

        self.pos_en = PosEnSine(self.feat_dim // 2)
        self.attn = OurMultiheadAttention(feat_dim, n_head)

        self.linear1 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.linear2 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.activation = nn.ReLU(inplace=True)

        self.norm1 = nn.BatchNorm2d(self.feat_dim)
        self.norm2 = nn.BatchNorm2d(self.feat_dim)

    def forward(self, src):
        if self.pos_en_flag:
            pos_embed = self.pos_en(src)
        else:
            pos_embed = 0

        # multi-head attention
        src2 = self.attn(
            q=src + pos_embed, k=src + pos_embed, v=src, attn_type=self.attn_type, P=self.P
        )[0]
        src = src + src2
        src = self.norm1(src)

        # feed forward
        src2 = self.linear2(self.activation(self.linear1(src)))
        src = src + src2
        src = self.norm2(src)

        return src


class TransformerEncoderUnitSparse(nn.Module):
    def __init__(self, feat_dim, n_head=8, pos_en_flag=True, ahw=None):
        super(TransformerEncoderUnitSparse, self).__init__()
        self.feat_dim = feat_dim
        self.pos_en_flag = pos_en_flag
        self.ahw = ahw    # [Ph, Pw, Qh, Qw]

        self.pos_en = PosEnSine(self.feat_dim // 2)
        self.attn1 = OurMultiheadAttention(feat_dim, n_head)    # long range
        self.attn2 = OurMultiheadAttention(feat_dim, n_head)    # short range

        self.linear1 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.linear2 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.activation = nn.ReLU(inplace=True)

        self.norm1 = nn.BatchNorm2d(self.feat_dim)
        self.norm2 = nn.BatchNorm2d(self.feat_dim)

    def forward(self, src):
        if self.pos_en_flag:
            pos_embed = self.pos_en(src)
        else:
            pos_embed = 0

        # multi-head long-range attention
        src2 = self.attn1(
            q=src + pos_embed,
            k=src + pos_embed,
            v=src,
            attn_type='sparse_long',
            ah=self.ahw[0],
            aw=self.ahw[1]
        )[0]
        src = src + src2    # ? this might be ok to remove

        # multi-head short-range attention
        src2 = self.attn2(
            q=src + pos_embed,
            k=src + pos_embed,
            v=src,
            attn_type='sparse_short',
            ah=self.ahw[2],
            aw=self.ahw[3]
        )[0]
        src = src + src2
        src = self.norm1(src)

        # feed forward
        src2 = self.linear2(self.activation(self.linear1(src)))
        src = src + src2
        src = self.norm2(src)

        return src


class TransformerDecoderUnit(nn.Module):
    def __init__(self, feat_dim, n_head=8, pos_en_flag=True, attn_type='softmax', P=None):
        super(TransformerDecoderUnit, self).__init__()
        self.feat_dim = feat_dim
        self.attn_type = attn_type
        self.pos_en_flag = pos_en_flag
        self.P = P

        self.pos_en = PosEnSine(self.feat_dim // 2)
        self.attn1 = OurMultiheadAttention(feat_dim, n_head)    # self-attention
        self.attn2 = OurMultiheadAttention(feat_dim, n_head)    # cross-attention

        self.linear1 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.linear2 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.activation = nn.ReLU(inplace=True)

        self.norm1 = nn.BatchNorm2d(self.feat_dim)
        self.norm2 = nn.BatchNorm2d(self.feat_dim)
        self.norm3 = nn.BatchNorm2d(self.feat_dim)

    def forward(self, tgt, src):
        if self.pos_en_flag:
            src_pos_embed = self.pos_en(src)
            tgt_pos_embed = self.pos_en(tgt)
        else:
            src_pos_embed = 0
            tgt_pos_embed = 0

        # self-multi-head attention
        tgt2 = self.attn1(
            q=tgt + tgt_pos_embed, k=tgt + tgt_pos_embed, v=tgt, attn_type=self.attn_type, P=self.P
        )[0]
        tgt = tgt + tgt2
        tgt = self.norm1(tgt)

        # cross-multi-head attention
        tgt2 = self.attn2(
            q=tgt + tgt_pos_embed, k=src + src_pos_embed, v=src, attn_type=self.attn_type, P=self.P
        )[0]
        tgt = tgt + tgt2
        tgt = self.norm2(tgt)

        # feed forward
        tgt2 = self.linear2(self.activation(self.linear1(tgt)))
        tgt = tgt + tgt2
        tgt = self.norm3(tgt)

        return tgt


class TransformerDecoderUnitSparse(nn.Module):
    def __init__(self, feat_dim, n_head=8, pos_en_flag=True, ahw=None):
        super(TransformerDecoderUnitSparse, self).__init__()
        self.feat_dim = feat_dim
        self.ahw = ahw    # [Ph_tgt, Pw_tgt, Qh_tgt, Qw_tgt, Ph_src, Pw_src, Qh_tgt, Qw_tgt]
        self.pos_en_flag = pos_en_flag

        self.pos_en = PosEnSine(self.feat_dim // 2)
        self.attn1_1 = OurMultiheadAttention(feat_dim, n_head)    # self-attention: long
        self.attn1_2 = OurMultiheadAttention(feat_dim, n_head)    # self-attention: short

        self.attn2_1 = OurMultiheadAttention(
            feat_dim, n_head
        )    # cross-attention: self-attention-long + cross-attention-short
        self.attn2_2 = OurMultiheadAttention(feat_dim, n_head)

        self.linear1 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.linear2 = nn.Conv2d(self.feat_dim, self.feat_dim, 1)
        self.activation = nn.ReLU(inplace=True)

        self.norm1 = nn.BatchNorm2d(self.feat_dim)
        self.norm2 = nn.BatchNorm2d(self.feat_dim)
        self.norm3 = nn.BatchNorm2d(self.feat_dim)

    def forward(self, tgt, src):
        if self.pos_en_flag:
            src_pos_embed = self.pos_en(src)
            tgt_pos_embed = self.pos_en(tgt)
        else:
            src_pos_embed = 0
            tgt_pos_embed = 0

        # self-multi-head attention: sparse long
        tgt2 = self.attn1_1(
            q=tgt + tgt_pos_embed,
            k=tgt + tgt_pos_embed,
            v=tgt,
            attn_type='sparse_long',
            ah=self.ahw[0],
            aw=self.ahw[1]
        )[0]
        tgt = tgt + tgt2
        # self-multi-head attention: sparse short
        tgt2 = self.attn1_2(
            q=tgt + tgt_pos_embed,
            k=tgt + tgt_pos_embed,
            v=tgt,
            attn_type='sparse_short',
            ah=self.ahw[2],
            aw=self.ahw[3]
        )[0]
        tgt = tgt + tgt2
        tgt = self.norm1(tgt)

        # self-multi-head attention: sparse long
        src2 = self.attn2_1(
            q=src + src_pos_embed,
            k=src + src_pos_embed,
            v=src,
            attn_type='sparse_long',
            ah=self.ahw[4],
            aw=self.ahw[5]
        )[0]
        src = src + src2
        # cross-multi-head attention: sparse short
        tgt2 = self.attn2_2(
            q=tgt + tgt_pos_embed,
            k=src + src_pos_embed,
            v=src,
            attn_type='sparse_short',
            ah=self.ahw[6],
            aw=self.ahw[7]
        )[0]
        tgt = tgt + tgt2
        tgt = self.norm2(tgt)

        # feed forward
        tgt2 = self.linear2(self.activation(self.linear1(tgt)))
        tgt = tgt + tgt2
        tgt = self.norm3(tgt)

        return tgt