""" Vision Transformer (ViT) in PyTorch A PyTorch implement of Vision Transformers as described in: 'An Image Is Worth 16 x 16 Words: Transformers for Image Recognition at Scale' - https://arxiv.org/abs/2010.11929 `How to train your ViT? Data, Augmentation, and Regularization in Vision Transformers` - https://arxiv.org/abs/2106.10270 The official jax code is released and available at https://github.com/google-research/vision_transformer DeiT model defs and weights from https://github.com/facebookresearch/deit, paper `DeiT: Data-efficient Image Transformers` - https://arxiv.org/abs/2012.12877 Acknowledgments: * The paper authors for releasing code and weights, thanks! * I fixed my class token impl based on Phil Wang's https://github.com/lucidrains/vit-pytorch ... check it out for some einops/einsum fun * Simple transformer style inspired by Andrej Karpathy's https://github.com/karpathy/minGPT * Bert reference code checks against Huggingface Transformers and Tensorflow Bert Hacked together by / Copyright 2021 Ross Wightman """ import math import logging from functools import partial from collections import OrderedDict from copy import deepcopy import torch import torch.nn as nn import torch.nn.functional as F from .layers import PatchEmbed, Mlp, DropPath, to_2tuple, trunc_normal_ from timm.data import IMAGENET_DEFAULT_MEAN, IMAGENET_DEFAULT_STD, IMAGENET_INCEPTION_MEAN, IMAGENET_INCEPTION_STD from .helpers import build_model_with_cfg, named_apply, adapt_input_conv from .layers import PatchEmbed, Mlp, DropPath, trunc_normal_, lecun_normal_ from .registry import register_model _logger = logging.getLogger(__name__) def _cfg(url='', **kwargs): return { 'url': url, 'num_classes': 1000, 'input_size': (3, 224, 224), 'pool_size': None, 'crop_pct': .9, 'interpolation': 'bicubic', 'fixed_input_size': True, 'mean': IMAGENET_INCEPTION_MEAN, 'std': IMAGENET_INCEPTION_STD, 'first_conv': 'patch_embed.proj', 'classifier': 'head', **kwargs } default_cfgs = { # patch models (weights from official Google JAX impl) 'vit_tiny_patch16_224': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'Ti_16-i21k-300ep-lr_0.001-aug_none-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_224.npz'), 'vit_tiny_patch16_384': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'Ti_16-i21k-300ep-lr_0.001-aug_none-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_384.npz', input_size=(3, 384, 384), crop_pct=1.0), 'vit_small_patch32_224': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'S_32-i21k-300ep-lr_0.001-aug_light1-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_224.npz'), 'vit_small_patch32_384': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'S_32-i21k-300ep-lr_0.001-aug_light1-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_384.npz', input_size=(3, 384, 384), crop_pct=1.0), 'vit_small_patch16_224': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'S_16-i21k-300ep-lr_0.001-aug_light1-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_224.npz'), 'vit_small_patch16_384': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'S_16-i21k-300ep-lr_0.001-aug_light1-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_384.npz', input_size=(3, 384, 384), crop_pct=1.0), 'vit_base_patch32_224': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'B_32-i21k-300ep-lr_0.001-aug_medium1-wd_0.03-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_224.npz'), 'vit_base_patch32_384': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'B_32-i21k-300ep-lr_0.001-aug_light1-wd_0.1-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.03-res_384.npz', input_size=(3, 384, 384), crop_pct=1.0), 'vit_base_patch16_224': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'B_16-i21k-300ep-lr_0.001-aug_medium1-wd_0.1-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.01-res_224.npz'), 'vit_base_patch16_384': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'B_16-i21k-300ep-lr_0.001-aug_medium1-wd_0.1-do_0.0-sd_0.0--imagenet2012-steps_20k-lr_0.01-res_384.npz', input_size=(3, 384, 384), crop_pct=1.0), 'vit_large_patch32_224': _cfg( url='', # no official model weights for this combo, only for in21k ), 'vit_large_patch32_384': _cfg( url='https://github.com/rwightman/pytorch-image-models/releases/download/v0.1-vitjx/jx_vit_large_p32_384-9b920ba8.pth', input_size=(3, 384, 384), crop_pct=1.0), 'vit_large_patch16_224': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'L_16-i21k-300ep-lr_0.001-aug_medium1-wd_0.1-do_0.1-sd_0.1--imagenet2012-steps_20k-lr_0.01-res_224.npz'), 'vit_large_patch16_384': _cfg( url='https://storage.googleapis.com/vit_models/augreg/' 'L_16-i21k-300ep-lr_0.001-aug_medium1-wd_0.1-do_0.1-sd_0.1--imagenet2012-steps_20k-lr_0.01-res_384.npz', input_size=(3, 384, 384), crop_pct=1.0), # patch models, imagenet21k (weights from official Google JAX impl) 'vit_tiny_patch16_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/augreg/Ti_16-i21k-300ep-lr_0.001-aug_none-wd_0.03-do_0.0-sd_0.0.npz', num_classes=21843), 'vit_small_patch32_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/augreg/S_32-i21k-300ep-lr_0.001-aug_light1-wd_0.03-do_0.0-sd_0.0.npz', num_classes=21843), 'vit_small_patch16_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/augreg/S_16-i21k-300ep-lr_0.001-aug_light1-wd_0.03-do_0.0-sd_0.0.npz', num_classes=21843), 'vit_base_patch32_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/augreg/B_32-i21k-300ep-lr_0.001-aug_medium1-wd_0.03-do_0.0-sd_0.0.npz', num_classes=21843), 'vit_base_patch16_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/augreg/B_16-i21k-300ep-lr_0.001-aug_medium1-wd_0.1-do_0.0-sd_0.0.npz', num_classes=21843), 'vit_large_patch32_224_in21k': _cfg( url='https://github.com/rwightman/pytorch-image-models/releases/download/v0.1-vitjx/jx_vit_large_patch32_224_in21k-9046d2e7.pth', num_classes=21843), 'vit_large_patch16_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/augreg/L_16-i21k-300ep-lr_0.001-aug_medium1-wd_0.1-do_0.1-sd_0.1.npz', num_classes=21843), 'vit_huge_patch14_224_in21k': _cfg( url='https://storage.googleapis.com/vit_models/imagenet21k/ViT-H_14.npz', hf_hub='timm/vit_huge_patch14_224_in21k', num_classes=21843), # deit models (FB weights) 'deit_tiny_patch16_224': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_tiny_patch16_224-a1311bcf.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD), 'deit_small_patch16_224': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_small_patch16_224-cd65a155.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD), 'deit_base_patch16_224': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_base_patch16_224-b5f2ef4d.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD), 'deit_base_patch16_384': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_base_patch16_384-8de9b5d1.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD, input_size=(3, 384, 384), crop_pct=1.0), 'deit_tiny_distilled_patch16_224': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_tiny_distilled_patch16_224-b40b3cf7.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD, classifier=('head', 'head_dist')), 'deit_small_distilled_patch16_224': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_small_distilled_patch16_224-649709d9.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD, classifier=('head', 'head_dist')), 'deit_base_distilled_patch16_224': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_base_distilled_patch16_224-df68dfff.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD, classifier=('head', 'head_dist')), 'deit_base_distilled_patch16_384': _cfg( url='https://dl.fbaipublicfiles.com/deit/deit_base_distilled_patch16_384-d0272ac0.pth', mean=IMAGENET_DEFAULT_MEAN, std=IMAGENET_DEFAULT_STD, input_size=(3, 384, 384), crop_pct=1.0, classifier=('head', 'head_dist')), # ViT ImageNet-21K-P pretraining by MILL 'vit_base_patch16_224_miil_in21k': _cfg( url='https://miil-public-eu.oss-eu-central-1.aliyuncs.com/model-zoo/ImageNet_21K_P/models/timm/vit_base_patch16_224_in21k_miil.pth', mean=(0, 0, 0), std=(1, 1, 1), crop_pct=0.875, interpolation='bilinear', num_classes=11221, ), 'vit_base_patch16_224_miil': _cfg( url='https://miil-public-eu.oss-eu-central-1.aliyuncs.com/model-zoo/ImageNet_21K_P/models/timm' '/vit_base_patch16_224_1k_miil_84_4.pth', mean=(0, 0, 0), std=(1, 1, 1), crop_pct=0.875, interpolation='bilinear', ), } class CrossAttention(nn.Module): def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None, attn_drop=0., proj_drop=0.): super().__init__() self.num_heads = num_heads head_dim = dim // num_heads self.scale = qk_scale or head_dim ** -0.5 #这行多了个qk_scale #0.125 self.wq = nn.Linear(dim, dim, bias=qkv_bias) self.wk = nn.Linear(dim, dim, bias=qkv_bias) self.wv = nn.Linear(dim, dim, bias=qkv_bias) self.attn_drop = nn.Dropout(attn_drop) self.proj = nn.Linear(dim, dim) self.proj_drop = nn.Dropout(proj_drop) def forward(self, x): B, N, C = x.shape #2 512 768 q = self.wq(x[:, 0:int(N/2), ...]).reshape(B, int(N/2), self.num_heads, C // self.num_heads).permute(0, 2, 1, 3)#2 12 256 64 k = self.wk(x[:, (int(N/2)):, ...]).reshape(B, int(N/2), self.num_heads, C // self.num_heads).permute(0, 2, 1, 3) v = self.wv(x[:, (int(N/2)):, ...]).reshape(B, int(N/2), self.num_heads, C // self.num_heads).permute(0, 2, 1, 3) attn = (q @ k.transpose(-2, -1)) * self.scale attn = attn.softmax(dim=-1) attn = self.attn_drop(attn) x = (attn @ v).transpose(1, 2).reshape(B, int(N/2), C) #变成了B/2 2 256 768 x = self.proj(x) x = self.proj_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.): super().__init__() self.num_heads = num_heads head_dim = dim // num_heads self.scale = qk_scale or head_dim ** -0.5 self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias) self.attn_drop = nn.Dropout(attn_drop) self.proj = nn.Linear(dim, dim) self.proj_drop = nn.Dropout(proj_drop) def forward(self, data): b,c,h = data.shape x,atten_mask = data[:,0:int(c/2),...],data[:,int(c/2):,...] B, N, C = x.shape qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4) q, k, v = qkv[0], qkv[1], qkv[2] #2,12,49,64 # make torchscript happy (cannot use tensor as tuple) attn = (q @ k.transpose(-2, -1)) * self.scale #2,12,49,49 #mask 2,1,49,49 if atten_mask.sum() != 0: atten_mask = atten_mask.unsqueeze(1) # 2,1,49,49 attn = attn + atten_mask attn = attn.softmax(dim=-1) attn = self.attn_drop(attn) x = (attn @ v).transpose(1, 2).reshape(B, N, C) x = self.proj(x) x = self.proj_drop(x) return x class Attention_ori(nn.Module): def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None,attn_drop=0., proj_drop=0.): super().__init__() self.num_heads = num_heads head_dim = dim // num_heads self.scale = qk_scale or head_dim ** -0.5 self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias) self.attn_drop = nn.Dropout(attn_drop) self.proj = nn.Linear(dim, dim) self.proj_drop = nn.Dropout(proj_drop) def forward(self, x): B, N, C = x.shape qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4) q, k, v = qkv[0], qkv[1], qkv[2] #2,12,49,64 # make torchscript happy (cannot use tensor as tuple) attn = (q @ k.transpose(-2, -1)) * self.scale #2,12,49,49 #mask 2,1,49,49 attn = attn.softmax(dim=-1) attn = self.attn_drop(attn) x = (attn @ v).transpose(1, 2).reshape(B, N, C) x = self.proj(x) x = self.proj_drop(x) return x class Block(nn.Module): def __init__(self, dim, num_heads, mlp_ratio=4., qkv_bias=False, drop=0., attn_drop=0., drop_path=0., act_layer=nn.GELU, norm_layer=nn.LayerNorm): super().__init__() self.norm1 = norm_layer(dim) self.attn = Attention(dim, num_heads=num_heads, qkv_bias=qkv_bias, attn_drop=attn_drop, proj_drop=drop) # NOTE: drop path for stochastic depth, we shall see if this is better than dropout here self.drop_path = DropPath(drop_path) if drop_path > 0. else 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) def forward(self, data): b,c,h = data.shape x,mask = data[:,0:int(c/2),...],data[:,int(c/2):,...] x = x + self.drop_path(self.attn(torch.cat([self.norm1(x),mask],dim=1))) x = x + self.drop_path(self.mlp(self.norm2(x))) return torch.cat([x,mask],dim=1) class mask_PatchEmbed(nn.Module): def __init__(self, img_size=224, patch_size=16, in_chans=3, norm_layer=None, flatten=True): 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.grid_size = (img_size[0] // patch_size[0], img_size[1] // patch_size[1]) self.flatten = flatten self.num_patches = self.grid_size[0] * self.grid_size[1] self.proj = nn.Conv2d(in_chans, 1, kernel_size=patch_size, stride=patch_size).requires_grad_(False) nn.init.ones_(self.proj.weight) nn.init.zeros_(self.proj.bias) def forward(self, x): B, C, H, W = x.shape assert H == self.img_size[0] and W == self.img_size[1], \ f"Input image size ({H}*{W}) doesn't match model ({self.img_size[0]}*{self.img_size[1]})." x = self.proj(x) if self.flatten: x = x.flatten(2).transpose(1, 2) # BCHW -> BNC return x class VisionTransformer(nn.Module): """ Vision Transformer A PyTorch impl of : `An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale` - https://arxiv.org/abs/2010.11929 Includes distillation token & head support for `DeiT: Data-efficient Image Transformers` - https://arxiv.org/abs/2012.12877 """ def __init__(self, img_size=224, patch_size=16, in_chans=3, num_classes=1000, embed_dim=768, depth=12, num_heads=12, mlp_ratio=4., qkv_bias=True, representation_size=None, distilled=False, drop_rate=0., attn_drop_rate=0., drop_path_rate=0., embed_layer=PatchEmbed, norm_layer=None, act_layer=None,as_backbone=True, weight_init=''): """ Args: img_size (int, tuple): input image size patch_size (int, tuple): patch size in_chans (int): number of input channels num_classes (int): number of classes for classification head embed_dim (int): embedding dimension depth (int): depth of transformer num_heads (int): number of attention heads mlp_ratio (int): ratio of mlp hidden dim to embedding dim qkv_bias (bool): enable bias for qkv if True representation_size (Optional[int]): enable and set representation layer (pre-logits) to this value if set distilled (bool): model includes a distillation token and head as in DeiT models drop_rate (float): dropout rate attn_drop_rate (float): attention dropout rate drop_path_rate (float): stochastic depth rate embed_layer (nn.Module): patch embedding layer norm_layer: (nn.Module): normalization layer weight_init: (str): weight init scheme """ super().__init__() self.num_classes = num_classes self.num_features = self.embed_dim = embed_dim # num_features for consistency with other models self.num_tokens = 2 if distilled else 1 self.num_heads = num_heads norm_layer = norm_layer or partial(nn.LayerNorm, eps=1e-6) act_layer = act_layer or nn.GELU self.as_backbone = as_backbone #是否分类任务，如果不是，class不加上去 self.patch_embed = embed_layer( img_size=img_size, patch_size=patch_size, in_chans=in_chans, embed_dim=embed_dim) self.mask_embed = mask_PatchEmbed(img_size=img_size, patch_size=patch_size, in_chans=in_chans) num_patches = self.patch_embed.num_patches self.cls_token = nn.Parameter(torch.zeros(1, 1, embed_dim)) self.dist_token = nn.Parameter(torch.zeros(1, 1, embed_dim)) if distilled else None if not self.as_backbone: self.pos_embed = nn.Parameter(torch.zeros(1, num_patches + self.num_tokens, embed_dim)) else: self.pos_embed = nn.Parameter(torch.zeros(1, num_patches, embed_dim)) self.pos_drop = nn.Dropout(p=drop_rate) dpr = [x.item() for x in torch.linspace(0, drop_path_rate, depth)] # stochastic depth decay rule self.blocks = nn.Sequential(*[ Block( dim=embed_dim, num_heads=num_heads, mlp_ratio=mlp_ratio, qkv_bias=qkv_bias, drop=drop_rate, attn_drop=attn_drop_rate, drop_path=dpr[i], norm_layer=norm_layer, act_layer=act_layer) for i in range(depth)]) self.norm = norm_layer(embed_dim) # Representation layer if representation_size and not distilled: self.num_features = representation_size self.pre_logits = nn.Sequential(OrderedDict([ ('fc', nn.Linear(embed_dim, representation_size)), ('act', nn.Tanh()) ])) else: self.pre_logits = nn.Identity() if not self.as_backbone: self.avgpool = nn.AdaptiveAvgPool1d(1) # Classifier head(s) self.head = nn.Linear(self.num_features, num_classes) if num_classes > 0 else nn.Identity() self.head_dist = None if distilled: self.head_dist = nn.Linear(self.embed_dim, self.num_classes) if num_classes > 0 else nn.Identity() self.init_weights(weight_init) def init_weights(self, mode=''): assert mode in ('jax', 'jax_nlhb', 'nlhb', '') head_bias = -math.log(self.num_classes) if 'nlhb' in mode else 0. trunc_normal_(self.pos_embed, std=.02) if self.dist_token is not None: trunc_normal_(self.dist_token, std=.02) if mode.startswith('jax'): # leave cls token as zeros to match jax impl named_apply(partial(_init_vit_weights, head_bias=head_bias, jax_impl=True), self) else: trunc_normal_(self.cls_token, std=.02) self.apply(_init_vit_weights) def _init_weights(self, m): # this fn left here for compat with downstream users _init_vit_weights(m) @torch.jit.ignore() def load_pretrained(self, checkpoint_path, prefix=''): _load_weights(self, checkpoint_path, prefix) @torch.jit.ignore def no_weight_decay(self): return {'pos_embed', 'cls_token', 'dist_token'} def get_classifier(self): if self.dist_token is None: return self.head else: return self.head, self.head_dist 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() if self.num_tokens == 2: self.head_dist = nn.Linear(self.embed_dim, self.num_classes) if num_classes > 0 else nn.Identity() def forward_features(self, data): x,mask = data[:,0,:,:].unsqueeze(1),data[:,1,:,:].unsqueeze(1) x = self.patch_embed(x)#B N C atten_mask = torch.zeros_like(x) # 2 49 768 if mask.sum() != 0: mask = self.mask_embed(mask) ### mask.squeeze_(dim=2) mask[mask != 0] = 1 ### H W数目token C编码长度 k1 = mask[:, None, :] k2 = torch.ones_like(mask)[:, :, None] k3 = k1 * k2 atten_mask = (1.0 - k3) * (-1e6) atten_mask.requires_grad_(True) self.atten_mask = atten_mask cls_token = self.cls_token.expand(x.shape[0], -1, -1) # stole cls_tokens impl from Phil Wang, thanks if not self.as_backbone: if self.dist_token is None: x = torch.cat((cls_token, x), dim=1) else: x = torch.cat((cls_token, self.dist_token.expand(x.shape[0], -1, -1), x), dim=1) x = self.pos_drop(x + self.pos_embed) #2 49 768 x = self.blocks(torch.cat([x,atten_mask],dim=1)) b,c,h = x.shape x = x[:,0:int(c/2),...] x = self.norm(x) if self.as_backbone: # x = self.avgpool(x.transpose(1, 2)) # B C 1 # x = torch.flatten(x, 1) return x if self.dist_token is None: return self.pre_logits(x[:, 0]) else: return x[:, 0], x[:, 1] def forward(self, data): x = self.forward_features(data) #2 49 768 if self.as_backbone: return x else: if self.head_dist is not None: x, x_dist = self.head(x[0]), self.head_dist(x[1]) # x must be a tuple if self.training and not torch.jit.is_scripting(): # during inference, return the average of both classifier predictions return x, x_dist else: return (x + x_dist) / 2 else: x = self.head(x) return x def _init_vit_weights(module: nn.Module, name: str = '', head_bias: float = 0., jax_impl: bool = False): """ ViT weight initialization * When called without n, head_bias, jax_impl args it will behave exactly the same as my original init for compatibility with prev hparam / downstream use cases (ie DeiT). * When called w/ valid n (module name) and jax_impl=True, will (hopefully) match JAX impl """ if isinstance(module, nn.Linear): if name.startswith('head'): nn.init.zeros_(module.weight) nn.init.constant_(module.bias, head_bias) elif name.startswith('pre_logits'): lecun_normal_(module.weight) nn.init.zeros_(module.bias) else: if jax_impl: nn.init.xavier_uniform_(module.weight) if module.bias is not None: if 'mlp' in name: nn.init.normal_(module.bias, std=1e-6) else: nn.init.zeros_(module.bias) else: trunc_normal_(module.weight, std=.02) if module.bias is not None: nn.init.zeros_(module.bias) elif jax_impl and isinstance(module, nn.Conv2d): # NOTE conv was left to pytorch default in my original init lecun_normal_(module.weight) if module.bias is not None: nn.init.zeros_(module.bias) elif isinstance(module, (nn.LayerNorm, nn.GroupNorm, nn.BatchNorm2d)): nn.init.zeros_(module.bias) nn.init.ones_(module.weight) @torch.no_grad() def _load_weights(model: VisionTransformer, checkpoint_path: str, prefix: str = ''): """ Load weights from .npz checkpoints for official Google Brain Flax implementation """ import numpy as np def _n2p(w, t=True): if w.ndim == 4 and w.shape[0] == w.shape[1] == w.shape[2] == 1: w = w.flatten() if t: if w.ndim == 4: w = w.transpose([3, 2, 0, 1]) elif w.ndim == 3: w = w.transpose([2, 0, 1]) elif w.ndim == 2: w = w.transpose([1, 0]) return torch.from_numpy(w) w = np.load(checkpoint_path) if not prefix and 'opt/target/embedding/kernel' in w: prefix = 'opt/target/' if hasattr(model.patch_embed, 'backbone'): # hybrid backbone = model.patch_embed.backbone stem_only = not hasattr(backbone, 'stem') stem = backbone if stem_only else backbone.stem stem.conv.weight.copy_(adapt_input_conv(stem.conv.weight.shape[1], _n2p(w[f'{prefix}conv_root/kernel']))) stem.norm.weight.copy_(_n2p(w[f'{prefix}gn_root/scale'])) stem.norm.bias.copy_(_n2p(w[f'{prefix}gn_root/bias'])) if not stem_only: for i, stage in enumerate(backbone.stages): for j, block in enumerate(stage.blocks): bp = f'{prefix}block{i + 1}/unit{j + 1}/' for r in range(3): getattr(block, f'conv{r + 1}').weight.copy_(_n2p(w[f'{bp}conv{r + 1}/kernel'])) getattr(block, f'norm{r + 1}').weight.copy_(_n2p(w[f'{bp}gn{r + 1}/scale'])) getattr(block, f'norm{r + 1}').bias.copy_(_n2p(w[f'{bp}gn{r + 1}/bias'])) if block.downsample is not None: block.downsample.conv.weight.copy_(_n2p(w[f'{bp}conv_proj/kernel'])) block.downsample.norm.weight.copy_(_n2p(w[f'{bp}gn_proj/scale'])) block.downsample.norm.bias.copy_(_n2p(w[f'{bp}gn_proj/bias'])) embed_conv_w = _n2p(w[f'{prefix}embedding/kernel']) else: embed_conv_w = adapt_input_conv( model.patch_embed.proj.weight.shape[1], _n2p(w[f'{prefix}embedding/kernel'])) model.patch_embed.proj.weight.copy_(embed_conv_w) model.patch_embed.proj.bias.copy_(_n2p(w[f'{prefix}embedding/bias'])) model.cls_token.copy_(_n2p(w[f'{prefix}cls'], t=False)) pos_embed_w = _n2p(w[f'{prefix}Transformer/posembed_input/pos_embedding'], t=False) if pos_embed_w.shape != model.pos_embed.shape: pos_embed_w = resize_pos_embed( # resize pos embedding when different size from pretrained weights pos_embed_w, model.pos_embed, getattr(model, 'num_tokens', 1), model.patch_embed.grid_size) model.pos_embed.copy_(pos_embed_w) model.norm.weight.copy_(_n2p(w[f'{prefix}Transformer/encoder_norm/scale'])) model.norm.bias.copy_(_n2p(w[f'{prefix}Transformer/encoder_norm/bias'])) if isinstance(model.head, nn.Linear) and model.head.bias.shape[0] == w[f'{prefix}head/bias'].shape[-1]: model.head.weight.copy_(_n2p(w[f'{prefix}head/kernel'])) model.head.bias.copy_(_n2p(w[f'{prefix}head/bias'])) if isinstance(getattr(model.pre_logits, 'fc', None), nn.Linear) and f'{prefix}pre_logits/bias' in w: model.pre_logits.fc.weight.copy_(_n2p(w[f'{prefix}pre_logits/kernel'])) model.pre_logits.fc.bias.copy_(_n2p(w[f'{prefix}pre_logits/bias'])) for i, block in enumerate(model.blocks.children()): block_prefix = f'{prefix}Transformer/encoderblock_{i}/' mha_prefix = block_prefix + 'MultiHeadDotProductAttention_1/' block.norm1.weight.copy_(_n2p(w[f'{block_prefix}LayerNorm_0/scale'])) block.norm1.bias.copy_(_n2p(w[f'{block_prefix}LayerNorm_0/bias'])) block.attn.qkv.weight.copy_(torch.cat([ _n2p(w[f'{mha_prefix}{n}/kernel'], t=False).flatten(1).T for n in ('query', 'key', 'value')])) block.attn.qkv.bias.copy_(torch.cat([ _n2p(w[f'{mha_prefix}{n}/bias'], t=False).reshape(-1) for n in ('query', 'key', 'value')])) block.attn.proj.weight.copy_(_n2p(w[f'{mha_prefix}out/kernel']).flatten(1)) block.attn.proj.bias.copy_(_n2p(w[f'{mha_prefix}out/bias'])) for r in range(2): getattr(block.mlp, f'fc{r + 1}').weight.copy_(_n2p(w[f'{block_prefix}MlpBlock_3/Dense_{r}/kernel'])) getattr(block.mlp, f'fc{r + 1}').bias.copy_(_n2p(w[f'{block_prefix}MlpBlock_3/Dense_{r}/bias'])) block.norm2.weight.copy_(_n2p(w[f'{block_prefix}LayerNorm_2/scale'])) block.norm2.bias.copy_(_n2p(w[f'{block_prefix}LayerNorm_2/bias'])) def resize_pos_embed(posemb, posemb_new, num_tokens=1, gs_new=()): # Rescale the grid of position embeddings when loading from state_dict. Adapted from # https://github.com/google-research/vision_transformer/blob/00883dd691c63a6830751563748663526e811cee/vit_jax/checkpoint.py#L224 _logger.info('Resized position embedding: %s to %s', posemb.shape, posemb_new.shape) ntok_new = posemb_new.shape[1] if num_tokens: posemb_tok, posemb_grid = posemb[:, :num_tokens], posemb[0, num_tokens:] ntok_new -= num_tokens else: posemb_tok, posemb_grid = posemb[:, :0], posemb[0] gs_old = int(math.sqrt(len(posemb_grid))) if not len(gs_new): # backwards compatibility gs_new = [int(math.sqrt(ntok_new))] * 2 assert len(gs_new) >= 2 _logger.info('Position embedding grid-size from %s to %s', [gs_old, gs_old], gs_new) posemb_grid = posemb_grid.reshape(1, gs_old, gs_old, -1).permute(0, 3, 1, 2) posemb_grid = F.interpolate(posemb_grid, size=gs_new, mode='bilinear') posemb_grid = posemb_grid.permute(0, 2, 3, 1).reshape(1, gs_new[0] * gs_new[1], -1) posemb = torch.cat([posemb_tok, posemb_grid], dim=1) return posemb def checkpoint_filter_fn(state_dict, model): """ convert patch embedding weight from manual patchify + linear proj to conv""" out_dict = {} if 'model' in state_dict: # For deit models state_dict = state_dict['model'] for k, v in state_dict.items(): if 'patch_embed.proj.weight' in k and len(v.shape) < 4: # For old models that I trained prior to conv based patchification O, I, H, W = model.patch_embed.proj.weight.shape v = v.reshape(O, -1, H, W) elif k == 'pos_embed' and v.shape != model.pos_embed.shape: # To resize pos embedding when using model at different size from pretrained weights v = resize_pos_embed( v, model.pos_embed, getattr(model, 'num_tokens', 1), model.patch_embed.grid_size) out_dict[k] = v return out_dict def _create_vision_transformer(variant, pretrained=False, default_cfg=None, **kwargs): default_cfg = default_cfg or default_cfgs[variant] if kwargs.get('features_only', None): raise RuntimeError('features_only not implemented for Vision Transformer models.') # NOTE this extra code to support handling of repr size for in21k pretrained models default_num_classes = default_cfg['num_classes'] num_classes = kwargs.get('num_classes', default_num_classes) repr_size = kwargs.pop('representation_size', None) if repr_size is not None and num_classes != default_num_classes: # Remove representation layer if fine-tuning. This may not always be the desired action, # but I feel better than doing nothing by default for fine-tuning. Perhaps a better interface? _logger.warning("Removing representation layer for fine-tuning.") repr_size = None model = build_model_with_cfg( VisionTransformer, variant, pretrained, default_cfg=default_cfg, representation_size=repr_size, pretrained_filter_fn=checkpoint_filter_fn, pretrained_custom_load='npz' in default_cfg['url'], **kwargs) return model @register_model def vit_tiny_patch16_224(pretrained=False, **kwargs): """ ViT-Tiny (Vit-Ti/16) """ model_kwargs = dict(patch_size=16, embed_dim=192, depth=12, num_heads=3, **kwargs) model = _create_vision_transformer('vit_tiny_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_tiny_patch16_384(pretrained=False, **kwargs): """ ViT-Tiny (Vit-Ti/16) @ 384x384. """ model_kwargs = dict(patch_size=16, embed_dim=192, depth=12, num_heads=3, **kwargs) model = _create_vision_transformer('vit_tiny_patch16_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_small_patch32_224(pretrained=False, **kwargs): """ ViT-Small (ViT-S/32) """ model_kwargs = dict(patch_size=32, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('vit_small_patch32_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_small_patch32_384(pretrained=False, **kwargs): """ ViT-Small (ViT-S/32) at 384x384. """ model_kwargs = dict(patch_size=32, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('vit_small_patch32_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_small_patch16_224(pretrained=False, **kwargs): """ ViT-Small (ViT-S/16) NOTE I've replaced my previous 'small' model definition and weights with the small variant from the DeiT paper """ model_kwargs = dict(patch_size=16, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('vit_small_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_small_patch16_384(pretrained=False, **kwargs): """ ViT-Small (ViT-S/16) NOTE I've replaced my previous 'small' model definition and weights with the small variant from the DeiT paper """ model_kwargs = dict(patch_size=16, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('vit_small_patch16_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch32_224(pretrained=False, **kwargs): """ ViT-Base (ViT-B/32) from original paper (https://arxiv.org/abs/2010.11929). No pretrained weights. """ model_kwargs = dict(patch_size=32, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('vit_base_patch32_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch32_384(pretrained=False, **kwargs): """ ViT-Base model (ViT-B/32) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-1k weights fine-tuned from in21k @ 384x384, source https://github.com/google-research/vision_transformer. """ model_kwargs = dict(patch_size=32, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('vit_base_patch32_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch16_224(pretrained=False, **kwargs): """ ViT-Base (ViT-B/16) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-1k weights fine-tuned from in21k @ 224x224, source https://github.com/google-research/vision_transformer. """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('vit_base_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch16_384(pretrained=False, **kwargs): """ ViT-Base model (ViT-B/16) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-1k weights fine-tuned from in21k @ 384x384, source https://github.com/google-research/vision_transformer. """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('vit_base_patch16_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_large_patch32_224(pretrained=False, **kwargs): """ ViT-Large model (ViT-L/32) from original paper (https://arxiv.org/abs/2010.11929). No pretrained weights. """ model_kwargs = dict(patch_size=32, embed_dim=1024, depth=24, num_heads=16, **kwargs) model = _create_vision_transformer('vit_large_patch32_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_large_patch32_384(pretrained=False, **kwargs): """ ViT-Large model (ViT-L/32) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-1k weights fine-tuned from in21k @ 384x384, source https://github.com/google-research/vision_transformer. """ model_kwargs = dict(patch_size=32, embed_dim=1024, depth=24, num_heads=16, **kwargs) model = _create_vision_transformer('vit_large_patch32_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_large_patch16_224(pretrained=False, **kwargs): """ ViT-Large model (ViT-L/32) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-1k weights fine-tuned from in21k @ 224x224, source https://github.com/google-research/vision_transformer. """ model_kwargs = dict(patch_size=16, embed_dim=1024, depth=24, num_heads=16, **kwargs) model = _create_vision_transformer('vit_large_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def vit_large_patch16_384(pretrained=False, **kwargs): """ ViT-Large model (ViT-L/16) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-1k weights fine-tuned from in21k @ 384x384, source https://github.com/google-research/vision_transformer. """ model_kwargs = dict(patch_size=16, embed_dim=1024, depth=24, num_heads=16, **kwargs) model = _create_vision_transformer('vit_large_patch16_384', pretrained=pretrained, **model_kwargs) return model @register_model def vit_tiny_patch16_224_in21k(pretrained=False, **kwargs): """ ViT-Tiny (Vit-Ti/16). ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has valid 21k classifier head and no representation (pre-logits) layer """ model_kwargs = dict(patch_size=16, embed_dim=192, depth=12, num_heads=3, **kwargs) model = _create_vision_transformer('vit_tiny_patch16_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_small_patch32_224_in21k(pretrained=False, **kwargs): """ ViT-Small (ViT-S/16) ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has valid 21k classifier head and no representation (pre-logits) layer """ model_kwargs = dict(patch_size=32, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('vit_small_patch32_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_small_patch16_224_in21k(pretrained=False, **kwargs): """ ViT-Small (ViT-S/16) ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has valid 21k classifier head and no representation (pre-logits) layer """ model_kwargs = dict(patch_size=16, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('vit_small_patch16_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch32_224_in21k(pretrained=False, **kwargs): """ ViT-Base model (ViT-B/32) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has valid 21k classifier head and no representation (pre-logits) layer """ model_kwargs = dict( patch_size=32, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('vit_base_patch32_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch16_224_in21k(pretrained=False, **kwargs): """ ViT-Base model (ViT-B/16) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has valid 21k classifier head and no representation (pre-logits) layer """ model_kwargs = dict( patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('vit_base_patch16_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_large_patch32_224_in21k(pretrained=False, **kwargs): """ ViT-Large model (ViT-L/32) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has a representation layer but the 21k classifier head is zero'd out in original weights """ model_kwargs = dict( patch_size=32, embed_dim=1024, depth=24, num_heads=16, representation_size=1024, **kwargs) model = _create_vision_transformer('vit_large_patch32_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_large_patch16_224_in21k(pretrained=False, **kwargs): """ ViT-Large model (ViT-L/16) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has valid 21k classifier head and no representation (pre-logits) layer """ model_kwargs = dict( patch_size=16, embed_dim=1024, depth=24, num_heads=16, **kwargs) model = _create_vision_transformer('vit_large_patch16_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_huge_patch14_224_in21k(pretrained=False, **kwargs): """ ViT-Huge model (ViT-H/14) from original paper (https://arxiv.org/abs/2010.11929). ImageNet-21k weights @ 224x224, source https://github.com/google-research/vision_transformer. NOTE: this model has a representation layer but the 21k classifier head is zero'd out in original weights """ model_kwargs = dict( patch_size=14, embed_dim=1280, depth=32, num_heads=16, representation_size=1280, **kwargs) model = _create_vision_transformer('vit_huge_patch14_224_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def deit_tiny_patch16_224(pretrained=False, **kwargs): """ DeiT-tiny model @ 224x224 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=192, depth=12, num_heads=3, **kwargs) model = _create_vision_transformer('deit_tiny_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def deit_small_patch16_224(pretrained=False, **kwargs): """ DeiT-small model @ 224x224 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer('deit_small_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def deit_base_patch16_224(pretrained=False, **kwargs): """ DeiT base model @ 224x224 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('deit_base_patch16_224', pretrained=pretrained, **model_kwargs) return model @register_model def deit_base_patch16_384(pretrained=False, **kwargs): """ DeiT base model @ 384x384 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer('deit_base_patch16_384', pretrained=pretrained, **model_kwargs) return model @register_model def deit_tiny_distilled_patch16_224(pretrained=False, **kwargs): """ DeiT-tiny distilled model @ 224x224 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=192, depth=12, num_heads=3, **kwargs) model = _create_vision_transformer( 'deit_tiny_distilled_patch16_224', pretrained=pretrained, distilled=True, **model_kwargs) return model @register_model def deit_small_distilled_patch16_224(pretrained=False, **kwargs): """ DeiT-small distilled model @ 224x224 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=384, depth=12, num_heads=6, **kwargs) model = _create_vision_transformer( 'deit_small_distilled_patch16_224', pretrained=pretrained, distilled=True, **model_kwargs) return model @register_model def deit_base_distilled_patch16_224(pretrained=False, **kwargs): """ DeiT-base distilled model @ 224x224 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer( 'deit_base_distilled_patch16_224', pretrained=pretrained, distilled=True, **model_kwargs) return model @register_model def deit_base_distilled_patch16_384(pretrained=False, **kwargs): """ DeiT-base distilled model @ 384x384 from paper (https://arxiv.org/abs/2012.12877). ImageNet-1k weights from https://github.com/facebookresearch/deit. """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, **kwargs) model = _create_vision_transformer( 'deit_base_distilled_patch16_384', pretrained=pretrained, distilled=True, **model_kwargs) return model @register_model def vit_base_patch16_224_miil_in21k(pretrained=False, **kwargs): """ ViT-Base (ViT-B/16) from original paper (https://arxiv.org/abs/2010.11929). Weights taken from: https://github.com/Alibaba-MIIL/ImageNet21K """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, qkv_bias=False, **kwargs) model = _create_vision_transformer('vit_base_patch16_224_miil_in21k', pretrained=pretrained, **model_kwargs) return model @register_model def vit_base_patch16_224_miil(pretrained=False, **kwargs): """ ViT-Base (ViT-B/16) from original paper (https://arxiv.org/abs/2010.11929). Weights taken from: https://github.com/Alibaba-MIIL/ImageNet21K """ model_kwargs = dict(patch_size=16, embed_dim=768, depth=12, num_heads=12, qkv_bias=False, **kwargs) model = _create_vision_transformer('vit_base_patch16_224_miil', pretrained=pretrained, **model_kwargs) return model