# 2022.06.08-Changed for implementation of TokenFusion # Huawei Technologies Co., Ltd. # --------------------------------------------------------------- # Copyright (c) 2021, NVIDIA Corporation. All rights reserved. # # This work is licensed under the NVIDIA Source Code License # --------------------------------------------------------------- import math import torch import torch.nn as nn import torch.nn.functional as F from functools import partial from timm.models.layers import DropPath, to_2tuple, trunc_normal_ from .modules import ModuleParallel, LayerNormParallel, num_parallel class Mlp(nn.Module): def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.GELU, drop=0.): super().__init__() out_features = out_features or in_features hidden_features = hidden_features or in_features self.fc1 = ModuleParallel(nn.Linear(in_features, hidden_features)) self.dwconv = DWConv(hidden_features) self.act = ModuleParallel(act_layer()) self.fc2 = ModuleParallel(nn.Linear(hidden_features, out_features)) self.drop = ModuleParallel(nn.Dropout(drop)) self.apply(self._init_weights) def _init_weights(self, m): if isinstance(m, nn.Linear): trunc_normal_(m.weight, std=.02) if isinstance(m, nn.Linear) and m.bias is not None: nn.init.constant_(m.bias, 0) elif isinstance(m, nn.LayerNorm): nn.init.constant_(m.bias, 0) nn.init.constant_(m.weight, 1.0) elif isinstance(m, nn.Conv2d): fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels fan_out //= m.groups m.weight.data.normal_(0, math.sqrt(2.0 / fan_out)) if m.bias is not None: m.bias.data.zero_() def forward(self, x, H, W): x = self.fc1(x) x = [self.dwconv(x[0], H, W)] x = self.act(x) x = self.drop(x) x = self.fc2(x) x = self.drop(x) return x class Attention(nn.Module): def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None, attn_drop=0., proj_drop=0., sr_ratio=1): super().__init__() assert dim % num_heads == 0, f"dim {dim} should be divided by num_heads {num_heads}." self.dim = dim self.num_heads = num_heads head_dim = dim // num_heads self.scale = qk_scale or head_dim ** -0.5 self.q = ModuleParallel(nn.Linear(dim, dim, bias=qkv_bias)) self.kv = ModuleParallel(nn.Linear(dim, dim * 2, bias=qkv_bias)) self.attn_drop = ModuleParallel(nn.Dropout(attn_drop)) self.proj = ModuleParallel(nn.Linear(dim, dim)) self.proj_drop = ModuleParallel(nn.Dropout(proj_drop)) self.sr_ratio = sr_ratio if sr_ratio > 1: self.sr = ModuleParallel(nn.Conv2d(dim, dim, kernel_size=sr_ratio, stride=sr_ratio)) self.norm = LayerNormParallel(dim) self.apply(self._init_weights) def _init_weights(self, m): if isinstance(m, nn.Linear): trunc_normal_(m.weight, std=.02) if isinstance(m, nn.Linear) and m.bias is not None: nn.init.constant_(m.bias, 0) elif isinstance(m, nn.LayerNorm): nn.init.constant_(m.bias, 0) nn.init.constant_(m.weight, 1.0) elif isinstance(m, nn.Conv2d): fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels fan_out //= m.groups m.weight.data.normal_(0, math.sqrt(2.0 / fan_out)) if m.bias is not None: m.bias.data.zero_() def forward(self, x, H, W): B, N, C = x[0].shape q = self.q(x) q = [q_.reshape(B, N, self.num_heads, C // self.num_heads).permute(0, 2, 1, 3) for q_ in q] if self.sr_ratio > 1: x = [x_.permute(0, 2, 1).reshape(B, C, H, W) for x_ in x] x = self.sr(x) x = [x_.reshape(B, C, -1).permute(0, 2, 1) for x_ in x] x = self.norm(x) kv = self.kv(x) kv = [kv_.reshape(B, -1, 2, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4) for kv_ in kv] else: kv = self.kv(x) kv = [kv_.reshape(B, -1, 2, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4) for kv_ in kv] # k, v = [kv[0][0], kv[1][0]], [kv[0][1], kv[1][1]] k, v = [kv[0][0]], [kv[0][1]] attn = [(q_ @ k_.transpose(-2, -1)) * self.scale for (q_, k_) in zip(q, k)] attn = [attn_.softmax(dim=-1) for attn_ in attn] attn = self.attn_drop(attn) x = [(attn_ @ v_).transpose(1, 2).reshape(B, N, C) for (attn_, v_) in zip(attn, v)] x = self.proj(x) x = self.proj_drop(x) return x # class PredictorLG(nn.Module): # """ Image to Patch Embedding from DydamicVit # """ # def __init__(self, embed_dim=384): # super().__init__() # self.score_nets = nn.ModuleList([nn.Sequential( # nn.LayerNorm(embed_dim), # nn.Linear(embed_dim, embed_dim), # nn.GELU(), # nn.Linear(embed_dim, embed_dim // 2), # nn.GELU(), # nn.Linear(embed_dim // 2, embed_dim // 4), # nn.GELU(), # nn.Linear(embed_dim // 4, 2), # nn.LogSoftmax(dim=-1) # ) for _ in range(num_parallel)]) # def forward(self, x): # x = [self.score_nets[i](x[i]) for i in range(num_parallel)] # return x class Block(nn.Module): def __init__(self, dim, num_heads, mlp_ratio=4., qkv_bias=False, qk_scale=None, drop=0., attn_drop=0., drop_path=0., act_layer=nn.GELU, norm_layer=LayerNormParallel, sr_ratio=1): super().__init__() self.norm1 = norm_layer(dim) # self.score = PredictorLG(dim) self.attn = Attention( dim, num_heads=num_heads, qkv_bias=qkv_bias, qk_scale=qk_scale, attn_drop=attn_drop, proj_drop=drop, sr_ratio=sr_ratio) # NOTE: drop path for stochastic depth, we shall see if this is better than dropout here self.drop_path = ModuleParallel(DropPath(drop_path)) if drop_path > 0. else ModuleParallel(nn.Identity()) self.norm2 = norm_layer(dim) mlp_hidden_dim = int(dim * mlp_ratio) self.mlp = Mlp(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop) # self.exchange = TokenExchange() self.apply(self._init_weights) def _init_weights(self, m): if isinstance(m, nn.Linear): trunc_normal_(m.weight, std=.02) if isinstance(m, nn.Linear) and m.bias is not None: nn.init.constant_(m.bias, 0) elif isinstance(m, nn.LayerNorm): nn.init.constant_(m.bias, 0) nn.init.constant_(m.weight, 1.0) elif isinstance(m, nn.Conv2d): fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels fan_out //= m.groups m.weight.data.normal_(0, math.sqrt(2.0 / fan_out)) if m.bias is not None: m.bias.data.zero_() def forward(self, x, H, W): B = x[0].shape[0] # norm1 = self.norm1(x) # score = self.score(norm1) # mask = [F.gumbel_softmax(score_.reshape(B, -1, 2), hard=True)[:, :, 0] for score_ in score] # if mask is not None: # norm = [norm_ * mask_.unsqueeze(2) for (norm_, mask_) in zip(norm, mask)] f = self.drop_path(self.attn(self.norm1(x), H, W)) x = [x_ + f_ for (x_, f_) in zip (x, f)] f = self.drop_path(self.mlp(self.norm2(x), H, W)) x = [x_ + f_ for (x_, f_) in zip (x, f)] # if mask is not None: # x = self.exchange(x, mask, mask_threshold=0.02) return x class OverlapPatchEmbed(nn.Module): """ Image to Patch Embedding """ def __init__(self, img_size=224, patch_size=7, stride=4, in_chans=3, embed_dim=768): super().__init__() img_size = to_2tuple(img_size) patch_size = to_2tuple(patch_size) self.img_size = img_size self.patch_size = patch_size self.H, self.W = img_size[0] // patch_size[0], img_size[1] // patch_size[1] self.num_patches = self.H * self.W self.proj = ModuleParallel(nn.Conv2d(in_chans, embed_dim, kernel_size=patch_size, stride=stride, padding=(patch_size[0] // 2, patch_size[1] // 2))) self.norm = LayerNormParallel(embed_dim) self.apply(self._init_weights) def _init_weights(self, m): if isinstance(m, nn.Linear): trunc_normal_(m.weight, std=.02) if isinstance(m, nn.Linear) and m.bias is not None: nn.init.constant_(m.bias, 0) elif isinstance(m, nn.LayerNorm): nn.init.constant_(m.bias, 0) nn.init.constant_(m.weight, 1.0) elif isinstance(m, nn.Conv2d): fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels fan_out //= m.groups m.weight.data.normal_(0, math.sqrt(2.0 / fan_out)) if m.bias is not None: m.bias.data.zero_() def forward(self, x): x = self.proj(x) _, _, H, W = x[0].shape x = [x_.flatten(2).transpose(1, 2) for x_ in x] x = self.norm(x) return x, H, W class MixVisionTransformer(nn.Module): def __init__(self, img_size=224, patch_size=16, in_chans=3, num_classes=1000, embed_dims=[64, 128, 256, 512], num_heads=[1, 2, 4, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=False, qk_scale=None, drop_rate=0., attn_drop_rate=0., drop_path_rate=0., norm_layer=LayerNormParallel, depths=[3, 4, 6, 3], sr_ratios=[8, 4, 2, 1]): super().__init__() self.num_classes = num_classes self.depths = depths self.embed_dims = embed_dims # patch_embed self.patch_embed1 = OverlapPatchEmbed(img_size=img_size, patch_size=7, stride=4, in_chans=in_chans, embed_dim=embed_dims[0]) self.patch_embed2 = OverlapPatchEmbed(img_size=img_size // 4, patch_size=3, stride=2, in_chans=embed_dims[0], embed_dim=embed_dims[1]) self.patch_embed3 = OverlapPatchEmbed(img_size=img_size // 8, patch_size=3, stride=2, in_chans=embed_dims[1], embed_dim=embed_dims[2]) self.patch_embed4 = OverlapPatchEmbed(img_size=img_size // 16, patch_size=3, stride=2, in_chans=embed_dims[2], embed_dim=embed_dims[3]) # predictor_list = [PredictorLG(embed_dims[i]) for i in range(len(depths))] # transformer encoder dpr = [x.item() for x in torch.linspace(0, drop_path_rate, sum(depths))] # stochastic depth decay rule cur = 0 self.block1 = nn.ModuleList([Block( dim=embed_dims[0], num_heads=num_heads[0], mlp_ratio=mlp_ratios[0], qkv_bias=qkv_bias, qk_scale=qk_scale, drop=drop_rate, attn_drop=attn_drop_rate, drop_path=dpr[cur + i], norm_layer=norm_layer, sr_ratio=sr_ratios[0]) for i in range(depths[0])]) self.norm1 = norm_layer(embed_dims[0]) cur += depths[0] self.block2 = nn.ModuleList([Block( dim=embed_dims[1], num_heads=num_heads[1], mlp_ratio=mlp_ratios[1], qkv_bias=qkv_bias, qk_scale=qk_scale, drop=drop_rate, attn_drop=attn_drop_rate, drop_path=dpr[cur + i], norm_layer=norm_layer, sr_ratio=sr_ratios[1]) for i in range(depths[1])]) self.norm2 = norm_layer(embed_dims[1]) cur += depths[1] self.block3 = nn.ModuleList([Block( dim=embed_dims[2], num_heads=num_heads[2], mlp_ratio=mlp_ratios[2], qkv_bias=qkv_bias, qk_scale=qk_scale, drop=drop_rate, attn_drop=attn_drop_rate, drop_path=dpr[cur + i], norm_layer=norm_layer, sr_ratio=sr_ratios[2]) for i in range(depths[2])]) self.norm3 = norm_layer(embed_dims[2]) cur += depths[2] self.block4 = nn.ModuleList([Block( dim=embed_dims[3], num_heads=num_heads[3], mlp_ratio=mlp_ratios[3], qkv_bias=qkv_bias, qk_scale=qk_scale, drop=drop_rate, attn_drop=attn_drop_rate, drop_path=dpr[cur + i], norm_layer=norm_layer, sr_ratio=sr_ratios[3]) for i in range(depths[3])]) self.norm4 = norm_layer(embed_dims[3]) # classification head # self.head = nn.Linear(embed_dims[3], num_classes) if num_classes > 0 else nn.Identity() self.apply(self._init_weights) def _init_weights(self, m): if isinstance(m, nn.Linear): trunc_normal_(m.weight, std=.02) if isinstance(m, nn.Linear) and m.bias is not None: nn.init.constant_(m.bias, 0) elif isinstance(m, nn.LayerNorm): nn.init.constant_(m.bias, 0) nn.init.constant_(m.weight, 1.0) elif isinstance(m, nn.Conv2d): fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels fan_out //= m.groups m.weight.data.normal_(0, math.sqrt(2.0 / fan_out)) if m.bias is not None: m.bias.data.zero_() ''' def init_weights(self, pretrained=None): if isinstance(pretrained, str): logger = get_root_logger() load_checkpoint(self, pretrained, map_location='cpu', strict=False, logger=logger) ''' def reset_drop_path(self, drop_path_rate): dpr = [x.item() for x in torch.linspace(0, drop_path_rate, sum(self.depths))] cur = 0 for i in range(self.depths[0]): self.block1[i].drop_path.drop_prob = dpr[cur + i] cur += self.depths[0] for i in range(self.depths[1]): self.block2[i].drop_path.drop_prob = dpr[cur + i] cur += self.depths[1] for i in range(self.depths[2]): self.block3[i].drop_path.drop_prob = dpr[cur + i] cur += self.depths[2] for i in range(self.depths[3]): self.block4[i].drop_path.drop_prob = dpr[cur + i] def freeze_patch_emb(self): self.patch_embed1.requires_grad = False @torch.jit.ignore def no_weight_decay(self): return {'pos_embed1', 'pos_embed2', 'pos_embed3', 'pos_embed4', 'cls_token'} # has pos_embed may be better def get_classifier(self): return self.head def reset_classifier(self, num_classes, global_pool=''): self.num_classes = num_classes self.head = nn.Linear(self.embed_dim, num_classes) if num_classes > 0 else nn.Identity() def forward_features(self, x): B = x[0].shape[0] outs0 = [] # stage 1 x, H, W = self.patch_embed1(x) for i, blk in enumerate(self.block1): x = blk(x, H, W) x = self.norm1(x) x = [x_.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous() for x_ in x] outs0.append(x[0]) # stage 2 x, H, W = self.patch_embed2(x) for i, blk in enumerate(self.block2): x = blk(x, H, W) x = self.norm2(x) x = [x_.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous() for x_ in x] outs0.append(x[0]) # stage 3 x, H, W = self.patch_embed3(x) for i, blk in enumerate(self.block3): x = blk(x, H, W) x = self.norm3(x) x = [x_.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous() for x_ in x] outs0.append(x[0]) # stage 4 x, H, W = self.patch_embed4(x) for i, blk in enumerate(self.block4): x = blk(x, H, W) x = self.norm4(x) x = [x_.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous() for x_ in x] outs0.append(x[0]) return [outs0] def forward(self, x): x = self.forward_features(x) return x class DWConv(nn.Module): def __init__(self, dim=768): super(DWConv, self).__init__() self.dwconv = nn.Conv2d(dim, dim, 3, 1, 1, bias=True, groups=dim) def forward(self, x, H, W): B, N, C = x.shape x = x.transpose(1, 2).contiguous().view(B, C, H, W) x = self.dwconv(x) x = x.flatten(2).transpose(1, 2).contiguous() return x class mit_b0(MixVisionTransformer): def __init__(self, **kwargs): super(mit_b0, self).__init__( patch_size=4, embed_dims=[32, 64, 160, 256], num_heads=[1, 2, 5, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=True, norm_layer=LayerNormParallel, depths=[2, 2, 2, 2], sr_ratios=[8, 4, 2, 1], drop_rate=0.0, drop_path_rate=0.1) class mit_b1(MixVisionTransformer): def __init__(self, **kwargs): super(mit_b1, self).__init__( patch_size=4, embed_dims=[64, 128, 320, 512], num_heads=[1, 2, 5, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=True, norm_layer=LayerNormParallel, depths=[2, 2, 2, 2], sr_ratios=[8, 4, 2, 1], drop_rate=0.0, drop_path_rate=0.1) class mit_b2(MixVisionTransformer): def __init__(self, **kwargs): super(mit_b2, self).__init__( patch_size=4, embed_dims=[64, 128, 320, 512], num_heads=[1, 2, 5, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=True, norm_layer=LayerNormParallel, depths=[3, 4, 6, 3], sr_ratios=[8, 4, 2, 1], drop_rate=0.0, drop_path_rate=0.1) class mit_b3(MixVisionTransformer): def __init__(self, **kwargs): super(mit_b3, self).__init__( patch_size=4, embed_dims=[64, 128, 320, 512], num_heads=[1, 2, 5, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=True, norm_layer=LayerNormParallel, depths=[3, 4, 18, 3], sr_ratios=[8, 4, 2, 1], drop_rate=0.0, drop_path_rate=0.1) class mit_b4(MixVisionTransformer): def __init__(self, **kwargs): super(mit_b4, self).__init__( patch_size=4, embed_dims=[64, 128, 320, 512], num_heads=[1, 2, 5, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=True, norm_layer=LayerNormParallel, depths=[3, 8, 27, 3], sr_ratios=[8, 4, 2, 1], drop_rate=0.0, drop_path_rate=0.1) class mit_b5(MixVisionTransformer): def __init__(self, **kwargs): super(mit_b5, self).__init__( patch_size=4, embed_dims=[64, 128, 320, 512], num_heads=[1, 2, 5, 8], mlp_ratios=[4, 4, 4, 4], qkv_bias=True, norm_layer=LayerNormParallel, depths=[3, 6, 40, 3], sr_ratios=[8, 4, 2, 1], drop_rate=0.0, drop_path_rate=0.1)