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models/transformer.py

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+import copy
+from typing import Optional, List
+
+import torch
+import torch.nn.functional as F
+from torch import nn, Tensor
+
+
+class Transformer_vis(nn.Module):
+
+    def __init__(self, d_model=256, nhead=8, num_encoder_layers=6,dim_feedforward=2048,
+                    dropout=0.1, activation="relu", normalize_before=False):
+        super().__init__()
+
+        encoder_layer = TransformerEncoderLayer(d_model, nhead, dim_feedforward,
+                                                dropout, activation, normalize_before)
+        encoder_norm = nn.LayerNorm(d_model) if normalize_before else None
+        self.encoder = TransformerEncoder(encoder_layer, num_encoder_layers, encoder_norm)
+
+        self._reset_parameters()
+
+        self.d_model = d_model
+        self.nhead = nhead
+
+    def _reset_parameters(self):
+        for p in self.parameters():
+            if p.dim() > 1:
+                nn.init.xavier_uniform_(p)
+
+    def forward(self, src, mask, pos_embed):
+        # flatten NxCxHxW to HWxNxC
+        bs, c, h, w = src.shape
+        src = src.flatten(2).permute(2, 0, 1)
+        pos_embed = pos_embed.flatten(2).permute(2, 0, 1)
+        mask = mask.flatten(1)
+        memory = self.encoder(src, src_key_padding_mask=mask, pos=pos_embed)
+        return memory.permute(1, 2, 0).view(bs, c, h, w)
+
+class Transformer_Decoder(nn.Module):
+    def __init__(self, d_model=512, nhead=8,
+                 num_decoder_layers=6, dim_feedforward=2048, dropout=0.1,
+                 activation="relu", normalize_before=False,
+                 return_intermediate_dec=False):
+        super().__init__()
+
+        decoder_layer = TransformerDecoderLayer(d_model, nhead, dim_feedforward,
+                                                dropout, activation, normalize_before)
+        decoder_norm = nn.LayerNorm(d_model)
+        self.decoder = TransformerDecoder(decoder_layer, num_decoder_layers, decoder_norm,
+                                          return_intermediate=return_intermediate_dec)
+
+        self._reset_parameters()
+
+        self.d_model = d_model
+        self.nhead = nhead
+
+    def _reset_parameters(self):
+        for p in self.parameters():
+            if p.dim() > 1:
+                nn.init.xavier_uniform_(p)
+
+    def forward(self, tgt, memory, mask,pos_embed, query_embed):
+        hs = self.decoder(tgt, memory, memory_key_padding_mask=mask,pos=pos_embed, query_pos=query_embed)
+        return hs
+
+class Transformer(nn.Module):
+
+    def __init__(self, d_model=256, nhead=8, num_encoder_layers=6,
+                 num_decoder_layers=6, dim_feedforward=2048, dropout=0.1,
+                 activation="relu", normalize_before=False,
+                 return_intermediate_dec=False):
+        super().__init__()
+
+        encoder_layer = TransformerEncoderLayer(d_model, nhead, dim_feedforward,
+                                                dropout, activation, normalize_before)
+        encoder_norm = nn.LayerNorm(d_model) if normalize_before else None
+        self.encoder = TransformerEncoder(encoder_layer, num_encoder_layers, encoder_norm)
+
+        self._reset_parameters()
+
+        self.d_model = d_model
+        self.nhead = nhead
+
+    def _reset_parameters(self):
+        for p in self.parameters():
+            if p.dim() > 1:
+                nn.init.xavier_uniform_(p)
+
+    def forward(self, src, mask, pos_embed):
+        # flatten NxCxHxW to HWxNxC
+        # permute NxCxW to WxNxC
+        src = src.permute(2, 0, 1)
+        pos_embed = pos_embed.permute(1, 0, 2)
+        memory = self.encoder(src, src_key_padding_mask=mask, pos=pos_embed)
+        return memory
+
+
+class TransformerEncoder(nn.Module):
+    def __init__(self, encoder_layer, num_layers, norm=None):
+        super().__init__()
+        self.layers = _get_clones(encoder_layer, num_layers)
+        self.num_layers = num_layers
+        self.norm = norm
+
+    def forward(self, src,
+                mask: Optional[Tensor] = None,  # 没有用mask
+                src_key_padding_mask: Optional[Tensor] = None,
+                pos: Optional[Tensor] = None):
+        output = src
+
+        for layer in self.layers:
+            output = layer(output, src_mask=mask,
+                           src_key_padding_mask=src_key_padding_mask, pos=pos)
+
+        if self.norm is not None:
+            output = self.norm(output)
+
+        return output
+
+
+class TransformerDecoder(nn.Module):
+
+    def __init__(self, decoder_layer, num_layers, norm=None, return_intermediate=False):
+        super().__init__()
+        self.layers = _get_clones(decoder_layer, num_layers)
+        self.num_layers = num_layers
+        self.norm = norm
+        self.return_intermediate = return_intermediate
+
+    def forward(self, tgt, memory,
+                tgt_mask: Optional[Tensor] = None,
+                memory_mask: Optional[Tensor] = None,
+                tgt_key_padding_mask: Optional[Tensor] = None,
+                memory_key_padding_mask: Optional[Tensor] = None,
+                pos: Optional[Tensor] = None,
+                query_pos: Optional[Tensor] = None):
+
+        output = tgt
+
+        intermediate = []
+
+        for layer in self.layers:
+            output = layer(output, memory, tgt_mask=tgt_mask,
+                           memory_mask=memory_mask,
+                           tgt_key_padding_mask=tgt_key_padding_mask,
+                           memory_key_padding_mask=memory_key_padding_mask,
+                           pos=pos, query_pos=query_pos)
+            if self.return_intermediate:
+                intermediate.append(self.norm(output))
+
+        if self.norm is not None:
+            output = self.norm(output)
+            if self.return_intermediate:
+                intermediate.pop()
+                intermediate.append(output)
+
+        if self.return_intermediate:
+            return torch.stack(intermediate)
+
+        return output.unsqueeze(0)
+
+
+class TransformerEncoderLayer(nn.Module):
+
+    def __init__(self, d_model, nhead, dim_feedforward=2048, dropout=0.1,
+                 activation="relu", normalize_before=False):
+        super().__init__()
+        self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=dropout)
+        # Implementation of Feedforward model
+        self.linear1 = nn.Linear(d_model, dim_feedforward)
+        self.dropout = nn.Dropout(dropout)
+        self.linear2 = nn.Linear(dim_feedforward, d_model)
+
+        self.norm1 = nn.LayerNorm(d_model)
+        self.norm2 = nn.LayerNorm(d_model)
+        self.dropout1 = nn.Dropout(dropout)
+        self.dropout2 = nn.Dropout(dropout)
+
+        self.activation = _get_activation_fn(activation)
+        self.normalize_before = normalize_before
+
+    def with_pos_embed(self, tensor, pos: Optional[Tensor]):
+        return tensor if pos is None else tensor + pos
+
+    def forward_post(self,
+                     src,
+                     src_mask: Optional[Tensor] = None,
+                     src_key_padding_mask: Optional[Tensor] = None,
+                     pos: Optional[Tensor] = None):
+        q = k = self.with_pos_embed(src, pos)
+        src2 = self.self_attn(q, k, value=src, attn_mask=src_mask,
+                              key_padding_mask=src_key_padding_mask)[0]
+        src = src + self.dropout1(src2)
+        src = self.norm1(src)
+        src2 = self.linear2(self.dropout(self.activation(self.linear1(src))))
+        src = src + self.dropout2(src2)
+        src = self.norm2(src)
+        return src
+
+    def forward_pre(self, src,
+                    src_mask: Optional[Tensor] = None,
+                    src_key_padding_mask: Optional[Tensor] = None,
+                    pos: Optional[Tensor] = None):
+        src2 = self.norm1(src)
+        q = k = self.with_pos_embed(src2, pos)
+        src2 = self.self_attn(q, k, value=src2, attn_mask=src_mask,
+                              key_padding_mask=src_key_padding_mask)[0]
+        src = src + self.dropout1(src2)
+        src2 = self.norm2(src)
+        src2 = self.linear2(self.dropout(self.activation(self.linear1(src2))))
+        src = src + self.dropout2(src2)
+        return src
+
+    def forward(self, src,
+                src_mask: Optional[Tensor] = None,
+                src_key_padding_mask: Optional[Tensor] = None,
+                pos: Optional[Tensor] = None):
+        if self.normalize_before:
+            return self.forward_pre(src, src_mask, src_key_padding_mask, pos)
+        return self.forward_post(src, src_mask, src_key_padding_mask, pos)
+
+
+class TransformerDecoderLayer(nn.Module):
+
+    def __init__(self, d_model, nhead, dim_feedforward=2048, dropout=0.1,
+                 activation="relu", normalize_before=False):
+        super().__init__()
+        self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=dropout)
+        self.multihead_attn = nn.MultiheadAttention(d_model, nhead, dropout=dropout)
+        # Implementation of Feedforward model
+        self.linear1 = nn.Linear(d_model, dim_feedforward)
+        self.dropout = nn.Dropout(dropout)
+        self.linear2 = nn.Linear(dim_feedforward, d_model)
+
+        self.norm1 = nn.LayerNorm(d_model)
+        self.norm2 = nn.LayerNorm(d_model)
+        self.norm3 = nn.LayerNorm(d_model)
+        self.dropout1 = nn.Dropout(dropout)
+        self.dropout2 = nn.Dropout(dropout)
+        self.dropout3 = nn.Dropout(dropout)
+
+        self.activation = _get_activation_fn(activation)
+        self.normalize_before = normalize_before
+
+    def with_pos_embed(self, tensor, pos: Optional[Tensor]):
+        return tensor if pos is None else tensor + pos
+
+    def forward_post(self, tgt, memory,
+                     tgt_mask: Optional[Tensor] = None,
+                     memory_mask: Optional[Tensor] = None,
+                     tgt_key_padding_mask: Optional[Tensor] = None,
+                     memory_key_padding_mask: Optional[Tensor] = None,
+                     pos: Optional[Tensor] = None,
+                     query_pos: Optional[Tensor] = None):
+        q = k = self.with_pos_embed(tgt, query_pos)
+        tgt2 = self.self_attn(q, k, value=tgt, attn_mask=tgt_mask,
+                              key_padding_mask=tgt_key_padding_mask)[0]
+        tgt = tgt + self.dropout1(tgt2)
+        tgt = self.norm1(tgt)
+        tgt2 = self.multihead_attn(query=self.with_pos_embed(tgt, query_pos),
+                                   key=self.with_pos_embed(memory, pos),
+                                   value=memory, attn_mask=memory_mask,
+                                   key_padding_mask=memory_key_padding_mask)[0]
+        tgt = tgt + self.dropout2(tgt2)
+        tgt = self.norm2(tgt)
+        tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt))))
+        tgt = tgt + self.dropout3(tgt2)
+        tgt = self.norm3(tgt)
+        return tgt
+
+    def forward_pre(self, tgt, memory,
+                    tgt_mask: Optional[Tensor] = None,
+                    memory_mask: Optional[Tensor] = None,
+                    tgt_key_padding_mask: Optional[Tensor] = None,
+                    memory_key_padding_mask: Optional[Tensor] = None,
+                    pos: Optional[Tensor] = None,
+                    query_pos: Optional[Tensor] = None):
+        tgt2 = self.norm1(tgt)
+        q = k = self.with_pos_embed(tgt2, query_pos)
+        tgt2 = self.self_attn(q, k, value=tgt2, attn_mask=tgt_mask,
+                              key_padding_mask=tgt_key_padding_mask)[0]
+        tgt = tgt + self.dropout1(tgt2)
+        tgt2 = self.norm2(tgt)
+        tgt2 = self.multihead_attn(query=self.with_pos_embed(tgt2, query_pos),
+                                   key=self.with_pos_embed(memory, pos),
+                                   value=memory, attn_mask=memory_mask,
+                                   key_padding_mask=memory_key_padding_mask)[0]
+        tgt = tgt + self.dropout2(tgt2)
+        tgt2 = self.norm3(tgt)
+        tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt2))))
+        tgt = tgt + self.dropout3(tgt2)
+        return tgt
+
+    def forward(self, tgt, memory,
+                tgt_mask: Optional[Tensor] = None,
+                memory_mask: Optional[Tensor] = None,
+                tgt_key_padding_mask: Optional[Tensor] = None,
+                memory_key_padding_mask: Optional[Tensor] = None,
+                pos: Optional[Tensor] = None,
+                query_pos: Optional[Tensor] = None):
+        if self.normalize_before:
+            return self.forward_pre(tgt, memory, tgt_mask, memory_mask,
+                                    tgt_key_padding_mask, memory_key_padding_mask, pos, query_pos)
+        return self.forward_post(tgt, memory, tgt_mask, memory_mask,
+                                 tgt_key_padding_mask, memory_key_padding_mask, pos, query_pos)
+
+def _get_clones(module, N):
+    return nn.ModuleList([copy.deepcopy(module) for i in range(N)])
+
+
+def build_vis_transformer(args):
+    return Transformer_vis(
+        d_model=args.hidden_dim,
+        dropout=args.dropout,
+        nhead=args.nheads,
+        dim_feedforward=args.dim_feedforward,
+        num_encoder_layers=args.enc_layers,
+        normalize_before=args.pre_norm,
+    )
+
+def build_de(args):
+    return Transformer_Decoder(
+        d_model=args.hidden_dim,
+        dropout=args.dropout,
+        nhead=args.nheads,
+        dim_feedforward=args.dim_feedforward,
+        num_decoder_layers=1,
+        normalize_before=args.pre_norm,
+        return_intermediate_dec=True
+    )
+
+
+def build_transformer(args):
+    return Transformer(
+        d_model=args.hidden_dim,
+        dropout=args.dropout,
+        nhead=args.nheads,
+        dim_feedforward=args.dim_feedforward,
+        num_encoder_layers=args.enc_layers,
+        num_decoder_layers=args.dec_layers,
+        normalize_before=args.pre_norm,
+        # TODO: return_intermediate_dec
+        return_intermediate_dec=True,
+    )
+
+def _get_activation_fn(activation):
+    """Return an activation function given a string"""
+    if activation == "relu":
+        return F.relu
+    if activation == "gelu":
+        return F.gelu
+    if activation == "glu":
+        return F.glu
+    raise RuntimeError(F"activation should be relu/gelu, not {activation}.")