| import torch.nn as nn
|
| import torch
|
| import torch.nn.functional as F
|
| import copy
|
|
|
| from contextlib import nullcontext
|
| import math
|
| from typing import Optional, Tuple
|
|
|
|
|
| from einops import rearrange
|
| from easydict import EasyDict as adict
|
|
|
|
|
| from typing import Optional, Tuple, Type
|
| from functools import partial
|
|
|
|
|
|
|
| class MlpProjector(nn.Module):
|
|
|
| def __init__(self, cfg):
|
|
|
| super().__init__()
|
|
|
| self.cfg = cfg
|
|
|
| if cfg.projector_type == "identity":
|
| modules = nn.Identity()
|
|
|
| elif cfg.projector_type == "linear":
|
| modules = nn.Linear(cfg.input_dim, cfg.n_embed)
|
|
|
| elif cfg.projector_type == "mlp_gelu":
|
| mlp_depth = cfg.get("depth", 1)
|
| modules = [nn.Linear(cfg.input_dim, cfg.n_embed)]
|
| for _ in range(1, mlp_depth):
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed, cfg.n_embed))
|
| modules = nn.Sequential(*modules)
|
|
|
| elif cfg.projector_type == "normlayer_downsample_mlp_gelu":
|
| mlp_depth = cfg.get("depth", 1)
|
| mlp_ratio = cfg.get("mlp_ratio", 1)
|
| modules = [
|
| nn.LayerNorm(cfg.input_dim * cfg.downsample_ratio * cfg.downsample_ratio),
|
| nn.Linear(cfg.input_dim * cfg.downsample_ratio * cfg.downsample_ratio, cfg.n_embed * mlp_ratio)
|
| ]
|
| for _ in range(1, mlp_depth - 1):
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed * mlp_ratio))
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed))
|
| modules = nn.Sequential(*modules)
|
|
|
| elif cfg.projector_type == "downsample_mlp_gelu":
|
| mlp_depth = cfg.get("depth", 1)
|
| mlp_ratio = cfg.get("mlp_ratio", 1)
|
| modules = [nn.Linear(cfg.input_dim * cfg.downsample_ratio * cfg.downsample_ratio, cfg.n_embed * mlp_ratio)]
|
| for _ in range(1, mlp_depth - 1):
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed * mlp_ratio))
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed * mlp_ratio, cfg.n_embed))
|
| modules = nn.Sequential(*modules)
|
|
|
| elif cfg.projector_type == "low_high_hybrid_split_mlp_gelu":
|
| mlp_depth = cfg.get("depth", 1)
|
| self.high_up_proj = nn.Linear(cfg.input_dim, cfg.n_embed // 2)
|
| self.low_up_proj = nn.Linear(cfg.input_dim, cfg.n_embed // 2)
|
|
|
| modules = []
|
| for _ in range(1, mlp_depth):
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed, cfg.n_embed))
|
| modules = nn.Sequential(*modules)
|
|
|
| elif cfg.projector_type == "hybrid_split_feature_mlp_gelu":
|
| mlp_depth = cfg.get("depth", 1)
|
| channel_div = cfg.get("channel_div", 0.5)
|
| self.high_up_proj = nn.Linear(cfg.input_dim[0], int(cfg.n_embed * channel_div))
|
| self.low_up_proj = nn.Linear(cfg.input_dim[1], cfg.n_embed - int(cfg.n_embed * channel_div))
|
|
|
| modules = []
|
| for _ in range(1, mlp_depth):
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed, cfg.n_embed))
|
| modules = nn.Sequential(*modules)
|
|
|
| elif cfg.projector_type == "low_high_split_mlp_gelu":
|
| mlp_depth = cfg.get("depth", 1)
|
| modules = []
|
| for _ in range(1, mlp_depth):
|
| modules.append(nn.GELU())
|
| modules.append(nn.Linear(cfg.n_embed // 2, cfg.n_embed // 2))
|
| modules = nn.Sequential(*modules)
|
| self.high_layers = nn.Sequential(*modules)
|
| self.low_layers = copy.deepcopy(modules)
|
|
|
| else:
|
| raise ValueError(f"Unknown projector type: {cfg.projector_type}")
|
|
|
| if cfg.get("token_pooling", False):
|
| self.token_pooling_layer = nn.Linear(cfg.input_dim * 4, cfg.input_dim)
|
|
|
| if cfg.get("conv_fusion_high_low_features", False):
|
| self.fusion_layer = nn.Linear(cfg.input_dim, cfg.input_dim)
|
| self.layers = modules
|
|
|
| def forward(self, x):
|
| if self.cfg.get("token_pooling", False):
|
| batch_size, wxh, channels = x.shape
|
| w = h = int(wxh**0.5)
|
| x = x.view(batch_size, w, h, channels)
|
| x = x.permute(0, 3, 1, 2)
|
|
|
| patches = x.unfold(2, 2, 2).unfold(3, 2, 2)
|
| batch_size, channels, h_patches, w_patches, _, _ = patches.size()
|
|
|
| patches = patches.contiguous().view(batch_size, channels, h_patches * w_patches, -1)
|
|
|
|
|
| patches = patches.permute(0, 2, 1, 3).contiguous()
|
| patches = patches.view(batch_size, h_patches * w_patches, channels * 4)
|
|
|
| x = self.token_pooling_layer(patches)
|
|
|
| if self.cfg.get("conv_fusion_high_low_features", False):
|
| x = self.fusion_layer(x[:, 0]) + x[:, 1]
|
|
|
| if self.cfg.projector_type == 'low_high_hybrid_split_mlp_gelu':
|
| high_x, low_x = x[0], x[1]
|
| high_x = self.high_up_proj(high_x)
|
| low_x = self.low_up_proj(low_x)
|
| x = torch.concat([high_x, low_x], dim=-1)
|
|
|
| if self.cfg.projector_type == 'hybrid_split_feature_mlp_gelu':
|
| high_x = x[...,:self.cfg.input_dim[0]]
|
| low_x = x[...,self.cfg.input_dim[0]:]
|
| high_x = self.high_up_proj(high_x)
|
| low_x = self.low_up_proj(low_x)
|
| x = torch.concat([high_x, low_x], dim=-1)
|
|
|
| if self.cfg.projector_type == 'low_high_split_mlp_gelu':
|
| high_x, low_x = x[0], x[1]
|
| high_x = self.high_layers(high_x)
|
| low_x = self.low_layers(low_x)
|
| x = torch.concat([high_x, low_x], dim=-1)
|
| return x
|
|
|
| if self.cfg.projector_type == 'downsample_mlp_gelu' or self.cfg.projector_type == 'normlayer_downsample_mlp_gelu':
|
| bs, hw, input_dim = x.shape
|
| h = w = int((hw) ** 0.5)
|
|
|
| """compute padding"""
|
| if h % self.cfg.downsample_ratio:
|
| pad = self.cfg.downsample_ratio - h % self.cfg.downsample_ratio
|
| else:
|
| pad = 0
|
| x = x.reshape(bs, h, w, input_dim)
|
| if pad > 0:
|
| x = F.pad(x, (0, 0, 0, pad, 0, pad), "constant", 0)
|
|
|
| """4 to 1 concat"""
|
| x = x.permute(0, 3, 1, 2)
|
| x = F.unfold(x, kernel_size=self.cfg.downsample_ratio, stride=self.cfg.downsample_ratio, padding=0)
|
| x = x.permute(0, 2, 1)
|
|
|
| return self.layers(x)
|
|
|
| @staticmethod
|
| def get_flops_per_sample(cfg):
|
| if cfg.projector_type == "linear":
|
| fwd = 2 * cfg.input_dim * cfg.n_embed
|
|
|
| elif "mlp_gelu" in cfg.projector_type :
|
| mlp_depth = cfg.get("depth", 1)
|
| downsample_ratio = cfg.get("downsample_ratio", 1)
|
| input_dim = sum(cfg.input_dim) if isinstance(cfg.input_dim, list) else cfg.input_dim
|
| input_dim = input_dim * downsample_ratio * downsample_ratio
|
| fwd = 2 * input_dim * cfg.n_embed + (mlp_depth - 1) * 2 * cfg.n_embed * cfg.n_embed
|
| else:
|
| fwd = 0
|
|
|
| return fwd * 3
|
|
|
|
|
|
|
|
|
| class LayerNormfp32(torch.nn.LayerNorm):
|
| """Subclass torch's LayerNorm to handle fp16."""
|
|
|
| def forward(self, x: torch.Tensor):
|
| orig_type = x.dtype
|
| ret = super().forward(x.type(torch.float32))
|
| return ret.type(orig_type)
|
|
|
|
|
| def get_abs_pos(abs_pos, tgt_size):
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| dim = abs_pos.size(-1)
|
|
|
| abs_pos_new = abs_pos.squeeze(0)
|
| cls_token, old_pos_embed = abs_pos_new[:1], abs_pos_new[1:]
|
|
|
|
|
|
|
| src_size = int(math.sqrt(abs_pos_new.shape[0] - 1))
|
| tgt_size = int(math.sqrt(tgt_size))
|
| dtype = abs_pos.dtype
|
|
|
| if src_size != tgt_size:
|
| old_pos_embed = old_pos_embed.view(1, src_size, src_size, dim).permute(0, 3, 1,
|
| 2).contiguous()
|
| old_pos_embed = old_pos_embed.to(torch.float32)
|
| new_pos_embed = F.interpolate(
|
| old_pos_embed,
|
| size=(tgt_size, tgt_size),
|
| mode='bicubic',
|
| antialias=True,
|
| align_corners=False,
|
| ).to(dtype)
|
| new_pos_embed = new_pos_embed.permute(0, 2, 3, 1)
|
| new_pos_embed = new_pos_embed.view(tgt_size * tgt_size, dim)
|
| vision_pos_embed = torch.cat([cls_token, new_pos_embed], dim=0)
|
| vision_pos_embed = vision_pos_embed.view(1, tgt_size * tgt_size + 1, dim)
|
| return vision_pos_embed
|
| else:
|
| return abs_pos
|
|
|
| @torch.jit.script
|
| def quick_gelu(x):
|
| return x * torch.sigmoid(1.702 * x)
|
|
|
|
|
|
|
| class CLIPVisionEmbeddings(nn.Module):
|
| def __init__(self, hidden_size=1024, image_size=224, patch_size=14, num_channels=3):
|
| super().__init__()
|
| self.embed_dim = hidden_size
|
| self.image_size = image_size
|
| self.patch_size = patch_size
|
|
|
| self.class_embedding = torch.nn.Parameter(torch.randn(self.embed_dim))
|
|
|
| self.patch_embedding = torch.nn.Conv2d(
|
| in_channels=num_channels,
|
| out_channels=self.embed_dim,
|
| kernel_size=self.patch_size,
|
| stride=self.patch_size,
|
| bias=False,
|
| )
|
|
|
| self.num_patches = (self.image_size // self.patch_size) ** 2
|
| self.num_positions = self.num_patches + 1
|
| self.position_embedding = torch.nn.Embedding(self.num_positions, self.embed_dim)
|
| self.register_buffer(
|
| "position_ids", torch.arange(self.num_positions).expand((1, -1))
|
| )
|
|
|
| def forward(self, pixel_values, patch_embeds):
|
| batch_size = pixel_values.shape[0]
|
|
|
|
|
|
|
|
|
|
|
| if patch_embeds is not None:
|
| patch_embeds = patch_embeds
|
|
|
| else:
|
| patch_embeds = self.patch_embedding(pixel_values)
|
|
|
|
|
|
|
|
|
| patch_embeds = patch_embeds.flatten(2).transpose(1, 2)
|
|
|
|
|
| class_embeds = self.class_embedding.expand(batch_size, 1, -1)
|
| embeddings = torch.cat([class_embeds, patch_embeds], dim=1)
|
|
|
|
|
| embeddings = embeddings + get_abs_pos(self.position_embedding(self.position_ids), embeddings.size(1))
|
|
|
| return embeddings
|
|
|
|
|
| class NoTPFeedForward(nn.Module):
|
| def __init__(
|
| self,
|
| cfg,
|
| dim: int,
|
| hidden_dim: int,
|
| ):
|
| super().__init__()
|
|
|
| self.fc1 = torch.nn.Linear(dim, hidden_dim, bias=True)
|
| self.fc2 = torch.nn.Linear(hidden_dim, dim, bias=True)
|
|
|
| def forward(self, x):
|
| output = self.fc2(quick_gelu(self.fc1(x)))
|
| return output
|
|
|
|
|
|
|
|
|
| class NoTPAttention(torch.nn.Module):
|
| def __init__(self, cfg):
|
| super().__init__()
|
| self.num_heads = cfg.num_attention_heads
|
| self.n_local_heads = cfg.num_attention_heads
|
| self.head_dim = cfg.hidden_size // cfg.num_attention_heads
|
| self.max_seq_len = cfg.seq_length
|
| self.use_flash_attention = cfg.use_flash_attn
|
|
|
| self.qkv_proj = torch.nn.Linear(cfg.hidden_size, cfg.hidden_size * 3, bias=True)
|
| self.out_proj = torch.nn.Linear(cfg.hidden_size, cfg.hidden_size, bias=True)
|
|
|
|
|
|
|
| self.attn_drop = cfg.attention_dropout
|
|
|
| def forward(
|
| self,
|
| x: torch.Tensor,
|
| ):
|
| bsz, seqlen, _ = x.shape
|
| xqkv = self.qkv_proj(x)
|
| xqkv = xqkv.view(bsz, seqlen, 3, self.num_heads, self.head_dim)
|
|
|
| if self.use_flash_attention:
|
|
|
| xq, xk, xv = torch.split(xqkv, 1, dim=2)
|
| xq = xq.squeeze(2)
|
| xk = xk.squeeze(2)
|
| xv = xv.squeeze(2)
|
|
|
|
|
|
|
| xq = xq.permute(0, 2, 1, 3)
|
| xk = xk.permute(0, 2, 1, 3)
|
| xv = xv.permute(0, 2, 1, 3)
|
|
|
| output = torch.nn.functional.scaled_dot_product_attention(xq, xk, xv, attn_mask=None)
|
| output = output.permute(0, 2, 1, 3).reshape(bsz, seqlen, -1)
|
|
|
| else:
|
|
|
| xq, xk, xv = torch.split(xqkv, 1, dim=2)
|
| xq = xq.squeeze(2)
|
| xk = xk.squeeze(2)
|
| xv = xv.squeeze(2)
|
|
|
|
|
|
|
| xq = xq.permute(0, 2, 1, 3)
|
| xk = xk.permute(0, 2, 1, 3)
|
| xv = xv.permute(0, 2, 1, 3)
|
|
|
| output = torch.nn.functional.scaled_dot_product_attention(xq, xk, xv, attn_mask=None)
|
| output = output.permute(0, 2, 1, 3).reshape(bsz, seqlen, -1)
|
|
|
| output = self.out_proj(output)
|
| return output
|
|
|
| class NoTPTransformerBlock(nn.Module):
|
| def __init__(self, cfg, layer_id: int, multiple_of=256):
|
| super().__init__()
|
|
|
| self.n_heads = cfg.num_attention_heads
|
| self.dim = cfg.hidden_size
|
| self.head_dim = cfg.hidden_size // cfg.num_attention_heads
|
| self.self_attn = NoTPAttention(cfg)
|
| self.mlp = NoTPFeedForward(
|
| cfg, dim=cfg.hidden_size, hidden_dim=cfg.ffn_hidden_size
|
| )
|
| self.layer_id = layer_id
|
| self.layer_norm1 = torch.nn.LayerNorm(
|
| cfg.hidden_size, eps=cfg.layernorm_epsilon
|
| )
|
| self.layer_norm2 = torch.nn.LayerNorm(
|
| cfg.hidden_size, eps=cfg.layernorm_epsilon
|
| )
|
|
|
| def forward(self, x: torch.Tensor):
|
| residual = self.self_attn.forward(self.layer_norm1(x))
|
| h = x + residual
|
| out = h + self.mlp.forward(self.layer_norm2(h))
|
| return out
|
|
|
|
|
| class NoTPTransformer(nn.Module):
|
| def __init__(self, cfg):
|
| super().__init__()
|
|
|
| self.cfg = cfg
|
|
|
| self.num_layers = cfg.num_layers
|
|
|
| self.layers = torch.nn.ModuleList()
|
| for layer_id in range(self.num_layers):
|
| self.layers.append(
|
| NoTPTransformerBlock(
|
| cfg,
|
| layer_id + 1,
|
| )
|
| )
|
|
|
| def forward(
|
| self,
|
| hidden_states,
|
| ):
|
|
|
| for lid, layer in enumerate(self.layers):
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| hidden_states = layer(hidden_states)
|
|
|
| return hidden_states
|
|
|
|
|
|
|
|
|
| class VitModel(nn.Module):
|
| def __init__(
|
| self,
|
| cfg,
|
| freeze_embed=False,
|
| freeze_pre_norm=False
|
| ) -> None:
|
| super().__init__()
|
|
|
| self.embeddings = CLIPVisionEmbeddings(hidden_size=cfg.hidden_size, image_size=cfg.image_size, patch_size=cfg.patch_size)
|
|
|
| if freeze_embed:
|
| for name, param in self.embeddings.named_parameters():
|
| param.requires_grad = False
|
|
|
| self.transformer = NoTPTransformer(cfg=cfg)
|
|
|
| if cfg.get("fp32norm", False):
|
| logger.info("Load fp32 layernorm for ViT.")
|
| self.pre_layrnorm = LayerNormfp32(
|
| cfg.hidden_size,
|
| eps=cfg.get("pre_layernorm_epsilon", 1e-5),
|
| )
|
| else:
|
| self.pre_layrnorm = torch.nn.LayerNorm(
|
| cfg.hidden_size,
|
| eps=cfg.get("pre_layernorm_epsilon", 1e-5),
|
| )
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| if freeze_pre_norm:
|
| for name, param in self.pre_layrnorm.named_parameters():
|
| param.requires_grad = False
|
|
|
| for p in self.parameters():
|
| p.micro_dp = True
|
|
|
| def set_input_tensor(self, input_tensor):
|
| if not isinstance(input_tensor, list):
|
| input_tensor = [input_tensor]
|
| self.transformer.set_input_tensor(input_tensor[0])
|
|
|
| def __str__(self) -> str:
|
| return "open_clip"
|
|
|
| def forward(
|
| self,
|
| x,
|
| patch_embeds
|
| ):
|
| x = self.embeddings(x, patch_embeds)
|
| hidden_states = self.pre_layrnorm(x)
|
|
|
|
|
| output = self.transformer(hidden_states)
|
|
|
|
|
|
|
| return output
|
|
|
|
|
| vit_model_cfg = adict(
|
| num_layers=24,
|
| hidden_size=1024,
|
| num_heads = 16,
|
| num_attention_heads=16,
|
| ffn_hidden_size=4096,
|
| seq_length=256,
|
| max_position_embeddings=256,
|
| use_flash_attn=False,
|
| understand_projector_stride=2,
|
| hidden_dropout = 0.0,
|
| attention_dropout = 0.0,
|
| no_persist_layer_norm = False,
|
| layernorm_epsilon = 1e-5,
|
| pre_layernorm_epsilon = 1e-5,
|
| image_size = 224,
|
| patch_size = 14,
|
| recompute_list = []
|
| )
|
|
|
| def build_clip_l():
|
| return VitModel(
|
| cfg=vit_model_cfg,
|
| freeze_embed=False,
|
| freeze_pre_norm=False,
|
| )
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| def get_abs_pos_sam(abs_pos, tgt_size):
|
|
|
| dtype = abs_pos.dtype
|
|
|
| src_size = abs_pos.size(1)
|
|
|
| if src_size != tgt_size:
|
| old_pos_embed = abs_pos.permute(0, 3, 1, 2)
|
| old_pos_embed = old_pos_embed.to(torch.float32)
|
| new_pos_embed = F.interpolate(
|
| old_pos_embed,
|
| size=(tgt_size, tgt_size),
|
| mode='bicubic',
|
| antialias=True,
|
| align_corners=False,
|
| ).to(dtype)
|
| new_pos_embed = new_pos_embed.permute(0, 2, 3, 1)
|
| return new_pos_embed
|
| else:
|
| return abs_pos
|
|
|
|
|
|
|
|
|
| class MLPBlock(nn.Module):
|
| def __init__(
|
| self,
|
| embedding_dim: int,
|
| mlp_dim: int,
|
| act: Type[nn.Module] = nn.GELU,
|
| ) -> None:
|
| super().__init__()
|
| self.lin1 = nn.Linear(embedding_dim, mlp_dim)
|
| self.lin2 = nn.Linear(mlp_dim, embedding_dim)
|
| self.act = act()
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| return self.lin2(self.act(self.lin1(x)))
|
|
|
|
|
|
|
|
|
| class LayerNorm2d(nn.Module):
|
| def __init__(self, num_channels: int, eps: float = 1e-6) -> None:
|
| super().__init__()
|
| self.weight = nn.Parameter(torch.ones(num_channels))
|
| self.bias = nn.Parameter(torch.zeros(num_channels))
|
| self.eps = eps
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| u = x.mean(1, keepdim=True)
|
| s = (x - u).pow(2).mean(1, keepdim=True)
|
| x = (x - u) / torch.sqrt(s + self.eps)
|
| x = self.weight[:, None, None] * x + self.bias[:, None, None]
|
| return x
|
|
|
|
|
|
|
| class ImageEncoderViT(nn.Module):
|
| def __init__(
|
| self,
|
| img_size: int = 1024,
|
| patch_size: int = 16,
|
| in_chans: int = 3,
|
| embed_dim: int = 768,
|
| depth: int = 12,
|
| num_heads: int = 12,
|
| mlp_ratio: float = 4.0,
|
| out_chans: int = 256,
|
| qkv_bias: bool = True,
|
| norm_layer: Type[nn.Module] = nn.LayerNorm,
|
| act_layer: Type[nn.Module] = nn.GELU,
|
| use_abs_pos: bool = True,
|
| use_rel_pos: bool = False,
|
| rel_pos_zero_init: bool = True,
|
| window_size: int = 0,
|
| global_attn_indexes: Tuple[int, ...] = (),
|
| ) -> None:
|
| """
|
| Args:
|
| img_size (int): Input image size.
|
| patch_size (int): Patch size.
|
| in_chans (int): Number of input image channels.
|
| embed_dim (int): Patch embedding dimension.
|
| depth (int): Depth of ViT.
|
| num_heads (int): Number of attention heads in each ViT block.
|
| mlp_ratio (float): Ratio of mlp hidden dim to embedding dim.
|
| qkv_bias (bool): If True, add a learnable bias to query, key, value.
|
| norm_layer (nn.Module): Normalization layer.
|
| act_layer (nn.Module): Activation layer.
|
| use_abs_pos (bool): If True, use absolute positional embeddings.
|
| use_rel_pos (bool): If True, add relative positional embeddings to the attention map.
|
| rel_pos_zero_init (bool): If True, zero initialize relative positional parameters.
|
| window_size (int): Window size for window attention blocks.
|
| global_attn_indexes (list): Indexes for blocks using global attention.
|
| """
|
| super().__init__()
|
| self.img_size = img_size
|
|
|
| self.patch_embed = PatchEmbed(
|
| kernel_size=(patch_size, patch_size),
|
| stride=(patch_size, patch_size),
|
| in_chans=in_chans,
|
| embed_dim=embed_dim,
|
| )
|
|
|
| self.pos_embed: Optional[nn.Parameter] = None
|
| if use_abs_pos:
|
|
|
| self.pos_embed = nn.Parameter(
|
| torch.zeros(1, img_size // patch_size, img_size // patch_size, embed_dim)
|
| )
|
|
|
| self.blocks = nn.ModuleList()
|
| for i in range(depth):
|
| block = Block(
|
| dim=embed_dim,
|
| num_heads=num_heads,
|
| mlp_ratio=mlp_ratio,
|
| qkv_bias=qkv_bias,
|
| norm_layer=norm_layer,
|
| act_layer=act_layer,
|
| use_rel_pos=use_rel_pos,
|
| rel_pos_zero_init=rel_pos_zero_init,
|
| window_size=window_size if i not in global_attn_indexes else 0,
|
| input_size=(img_size // patch_size, img_size // patch_size),
|
| )
|
| self.blocks.append(block)
|
|
|
| self.neck = nn.Sequential(
|
| nn.Conv2d(
|
| embed_dim,
|
| out_chans,
|
| kernel_size=1,
|
| bias=False,
|
| ),
|
| LayerNorm2d(out_chans),
|
| nn.Conv2d(
|
| out_chans,
|
| out_chans,
|
| kernel_size=3,
|
| padding=1,
|
| bias=False,
|
| ),
|
| LayerNorm2d(out_chans),
|
| )
|
|
|
| self.net_2 = nn.Conv2d(256, 512, kernel_size=3, stride=2, padding=1, bias=False)
|
| self.net_3 = nn.Conv2d(512, 1024, kernel_size=3, stride=2, padding=1, bias=False)
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| x = self.patch_embed(x)
|
| if self.pos_embed is not None:
|
|
|
| x = x + get_abs_pos_sam(self.pos_embed, x.size(1))
|
|
|
| for blk in self.blocks:
|
| x = blk(x)
|
|
|
| x = self.neck(x.permute(0, 3, 1, 2))
|
| x2 = self.net_2(x)
|
| x3 = self.net_3(x2.clone())
|
|
|
| return x3
|
|
|
|
|
| class Block(nn.Module):
|
| """Transformer blocks with support of window attention and residual propagation blocks"""
|
|
|
| def __init__(
|
| self,
|
| dim: int,
|
| num_heads: int,
|
| mlp_ratio: float = 4.0,
|
| qkv_bias: bool = True,
|
| norm_layer: Type[nn.Module] = nn.LayerNorm,
|
| act_layer: Type[nn.Module] = nn.GELU,
|
| use_rel_pos: bool = False,
|
| rel_pos_zero_init: bool = True,
|
| window_size: int = 0,
|
| input_size: Optional[Tuple[int, int]] = None,
|
| ) -> None:
|
| """
|
| Args:
|
| dim (int): Number of input channels.
|
| num_heads (int): Number of attention heads in each ViT block.
|
| mlp_ratio (float): Ratio of mlp hidden dim to embedding dim.
|
| qkv_bias (bool): If True, add a learnable bias to query, key, value.
|
| norm_layer (nn.Module): Normalization layer.
|
| act_layer (nn.Module): Activation layer.
|
| use_rel_pos (bool): If True, add relative positional embeddings to the attention map.
|
| rel_pos_zero_init (bool): If True, zero initialize relative positional parameters.
|
| window_size (int): Window size for window attention blocks. If it equals 0, then
|
| use global attention.
|
| input_size (tuple(int, int) or None): Input resolution for calculating the relative
|
| positional parameter size.
|
| """
|
| super().__init__()
|
| self.norm1 = norm_layer(dim)
|
| self.attn = Attention(
|
| dim,
|
| num_heads=num_heads,
|
| qkv_bias=qkv_bias,
|
| use_rel_pos=use_rel_pos,
|
| rel_pos_zero_init=rel_pos_zero_init,
|
| input_size=input_size if window_size == 0 else (window_size, window_size),
|
| )
|
|
|
| self.norm2 = norm_layer(dim)
|
| self.mlp = MLPBlock(embedding_dim=dim, mlp_dim=int(dim * mlp_ratio), act=act_layer)
|
|
|
| self.window_size = window_size
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| shortcut = x
|
| x = self.norm1(x)
|
|
|
| if self.window_size > 0:
|
| H, W = x.shape[1], x.shape[2]
|
| x, pad_hw = window_partition(x, self.window_size)
|
|
|
| x = self.attn(x)
|
|
|
| if self.window_size > 0:
|
| x = window_unpartition(x, self.window_size, pad_hw, (H, W))
|
|
|
| x = shortcut + x
|
| x = x + self.mlp(self.norm2(x))
|
|
|
| return x
|
|
|
|
|
| class Attention(nn.Module):
|
| """Multi-head Attention block with relative position embeddings."""
|
|
|
| def __init__(
|
| self,
|
| dim: int,
|
| num_heads: int = 8,
|
| qkv_bias: bool = True,
|
| use_rel_pos: bool = False,
|
| rel_pos_zero_init: bool = True,
|
| input_size: Optional[Tuple[int, int]] = None,
|
| ) -> None:
|
| """
|
| Args:
|
| dim (int): Number of input channels.
|
| num_heads (int): Number of attention heads.
|
| qkv_bias (bool): If True, add a learnable bias to query, key, value.
|
| rel_pos (bool): If True, add relative positional embeddings to the attention map.
|
| rel_pos_zero_init (bool): If True, zero initialize relative positional parameters.
|
| input_size (tuple(int, int) or None): Input resolution for calculating the relative
|
| positional parameter size.
|
| """
|
| super().__init__()
|
| self.num_heads = num_heads
|
| head_dim = dim // num_heads
|
| self.scale = head_dim**-0.5
|
|
|
| self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
|
| self.proj = nn.Linear(dim, dim)
|
|
|
| self.use_rel_pos = use_rel_pos
|
| if self.use_rel_pos:
|
| assert (
|
| input_size is not None
|
| ), "Input size must be provided if using relative positional encoding."
|
|
|
| self.rel_pos_h = nn.Parameter(torch.zeros(2 * input_size[0] - 1, head_dim))
|
| self.rel_pos_w = nn.Parameter(torch.zeros(2 * input_size[1] - 1, head_dim))
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| B, H, W, _ = x.shape
|
|
|
| qkv = self.qkv(x).reshape(B, H * W, 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)
|
|
|
| q, k, v = qkv.reshape(3, B * self.num_heads, H * W, -1).unbind(0)
|
|
|
| rel_h, rel_w = None, None
|
| if self.use_rel_pos:
|
| rel_h, rel_w = add_decomposed_rel_pos(q, self.rel_pos_h, self.rel_pos_w, (H, W), (H, W))
|
|
|
| q = q.view(B, self.num_heads, H * W, -1)
|
| k = k.view(B, self.num_heads, H * W, -1)
|
| v = v.view(B, self.num_heads, H * W, -1)
|
|
|
| if self.use_rel_pos:
|
| rel_h = rel_h.view(B, self.num_heads, rel_h.size(1), rel_h.size(2), rel_h.size(3))
|
| rel_w = rel_w.view(B, self.num_heads, rel_w.size(1), rel_w.size(2), rel_w.size(3))
|
| attn_bias = (rel_h + rel_w).view(B, self.num_heads, rel_h.size(2), rel_h.size(3) * rel_w.size(4))
|
| x = torch.nn.functional.scaled_dot_product_attention(q, k, v, attn_mask=attn_bias)
|
|
|
| else:
|
| x = torch.nn.functional.scaled_dot_product_attention(q, k, v)
|
|
|
| x = x.view(B, self.num_heads, H, W, -1).permute(0, 2, 3, 1, 4).reshape(B, H, W, -1)
|
|
|
| x = self.proj(x)
|
|
|
| return x
|
|
|
|
|
| def window_partition(x: torch.Tensor, window_size: int) -> Tuple[torch.Tensor, Tuple[int, int]]:
|
| """
|
| Partition into non-overlapping windows with padding if needed.
|
| Args:
|
| x (tensor): input tokens with [B, H, W, C].
|
| window_size (int): window size.
|
|
|
| Returns:
|
| windows: windows after partition with [B * num_windows, window_size, window_size, C].
|
| (Hp, Wp): padded height and width before partition
|
| """
|
| B, H, W, C = x.shape
|
|
|
| pad_h = (window_size - H % window_size) % window_size
|
| pad_w = (window_size - W % window_size) % window_size
|
| if pad_h > 0 or pad_w > 0:
|
| x = F.pad(x, (0, 0, 0, pad_w, 0, pad_h))
|
| Hp, Wp = H + pad_h, W + pad_w
|
|
|
| x = x.view(B, Hp // window_size, window_size, Wp // window_size, window_size, C)
|
| windows = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, window_size, window_size, C)
|
| return windows, (Hp, Wp)
|
|
|
|
|
| def window_unpartition(
|
| windows: torch.Tensor, window_size: int, pad_hw: Tuple[int, int], hw: Tuple[int, int]
|
| ) -> torch.Tensor:
|
| """
|
| Window unpartition into original sequences and removing padding.
|
| Args:
|
| windows (tensor): input tokens with [B * num_windows, window_size, window_size, C].
|
| window_size (int): window size.
|
| pad_hw (Tuple): padded height and width (Hp, Wp).
|
| hw (Tuple): original height and width (H, W) before padding.
|
|
|
| Returns:
|
| x: unpartitioned sequences with [B, H, W, C].
|
| """
|
| Hp, Wp = pad_hw
|
| H, W = hw
|
| B = windows.shape[0] // (Hp * Wp // window_size // window_size)
|
| x = windows.view(B, Hp // window_size, Wp // window_size, window_size, window_size, -1)
|
| x = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, Hp, Wp, -1)
|
|
|
| if Hp > H or Wp > W:
|
| x = x[:, :H, :W, :].contiguous()
|
| return x
|
|
|
|
|
| def get_rel_pos(q_size: int, k_size: int, rel_pos: torch.Tensor) -> torch.Tensor:
|
| """
|
| Get relative positional embeddings according to the relative positions of
|
| query and key sizes.
|
| Args:
|
| q_size (int): size of query q.
|
| k_size (int): size of key k.
|
| rel_pos (Tensor): relative position embeddings (L, C).
|
|
|
| Returns:
|
| Extracted positional embeddings according to relative positions.
|
| """
|
| max_rel_dist = int(2 * max(q_size, k_size) - 1)
|
|
|
| if rel_pos.shape[0] != max_rel_dist:
|
|
|
| dtype = rel_pos.dtype
|
| rel_pos = rel_pos.to(torch.float32)
|
| rel_pos_resized = F.interpolate(
|
| rel_pos.reshape(1, rel_pos.shape[0], -1).permute(0, 2, 1),
|
| size=max_rel_dist,
|
| mode="linear",
|
| ).to(dtype)
|
| rel_pos_resized = rel_pos_resized.reshape(-1, max_rel_dist).permute(1, 0)
|
| else:
|
| rel_pos_resized = rel_pos
|
|
|
|
|
| q_coords = torch.arange(q_size, device=rel_pos.device)[:, None] * max(k_size / q_size, 1.0)
|
| k_coords = torch.arange(k_size, device=rel_pos.device)[None, :] * max(q_size / k_size, 1.0)
|
| relative_coords = (q_coords - k_coords) + (k_size - 1) * max(q_size / k_size, 1.0)
|
|
|
| return rel_pos_resized[relative_coords.long()]
|
|
|
|
|
| def add_decomposed_rel_pos(
|
| q: torch.Tensor,
|
| rel_pos_h: torch.Tensor,
|
| rel_pos_w: torch.Tensor,
|
| q_size: Tuple[int, int],
|
| k_size: Tuple[int, int],
|
| ) -> torch.Tensor:
|
| """
|
| Calculate decomposed Relative Positional Embeddings from :paper:`mvitv2`.
|
| https://github.com/facebookresearch/mvit/blob/19786631e330df9f3622e5402b4a419a263a2c80/mvit/models/attention.py # noqa B950
|
| Args:
|
| q (Tensor): query q in the attention layer with shape (B, q_h * q_w, C).
|
| rel_pos_h (Tensor): relative position embeddings (Lh, C) for height axis.
|
| rel_pos_w (Tensor): relative position embeddings (Lw, C) for width axis.
|
| q_size (Tuple): spatial sequence size of query q with (q_h, q_w).
|
| k_size (Tuple): spatial sequence size of key k with (k_h, k_w).
|
|
|
| Returns:
|
| attn (Tensor): attention map with added relative positional embeddings.
|
| """
|
| q_h, q_w = q_size
|
| k_h, k_w = k_size
|
| Rh = get_rel_pos(q_h, k_h, rel_pos_h)
|
| Rw = get_rel_pos(q_w, k_w, rel_pos_w)
|
|
|
| B, _, dim = q.shape
|
| r_q = q.reshape(B, q_h, q_w, dim)
|
| rel_h = torch.einsum("bhwc,hkc->bhwk", r_q, Rh)
|
| rel_w = torch.einsum("bhwc,wkc->bhwk", r_q, Rw)
|
| rel_h = rel_h.unsqueeze(-1)
|
| rel_w = rel_w.unsqueeze(-2)
|
| rel_h = rel_h.reshape(B, q_h * q_w, k_h, 1)
|
| rel_w = rel_w.reshape(B, q_h * q_w, 1, k_w)
|
|
|
| return rel_h, rel_w
|
|
|
|
|
| class PatchEmbed(nn.Module):
|
| """
|
| Image to Patch Embedding.
|
| """
|
|
|
| def __init__(
|
| self,
|
| kernel_size: Tuple[int, int] = (16, 16),
|
| stride: Tuple[int, int] = (16, 16),
|
| padding: Tuple[int, int] = (0, 0),
|
| in_chans: int = 3,
|
| embed_dim: int = 768,
|
| ) -> None:
|
| """
|
| Args:
|
| kernel_size (Tuple): kernel size of the projection layer.
|
| stride (Tuple): stride of the projection layer.
|
| padding (Tuple): padding size of the projection layer.
|
| in_chans (int): Number of input image channels.
|
| embed_dim (int): Patch embedding dimension.
|
| """
|
| super().__init__()
|
|
|
| self.proj = nn.Conv2d(
|
| in_chans, embed_dim, kernel_size=kernel_size, stride=stride, padding=padding
|
| )
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| x = self.proj(x)
|
|
|
| x = x.permute(0, 2, 3, 1)
|
| return x
|
|
|
|
|
| def build_sam_vit_b(checkpoint=None):
|
| return _build_sam(
|
| encoder_embed_dim=768,
|
| encoder_depth=12,
|
| encoder_num_heads=12,
|
| encoder_global_attn_indexes=[2, 5, 8, 11],
|
| checkpoint=checkpoint,
|
| )
|
|
|
| def build_sam_fast_vit_b(checkpoint=None, compile_mode='max-autotune', dtype=torch.bfloat16):
|
| image_encoder = build_sam_vit_b(checkpoint).eval().to(dtype)
|
|
|
| image_encoder = torch.compile(image_encoder, mode=compile_mode)
|
| return image_encoder
|
|
|
|
|
| def _build_sam(
|
| encoder_embed_dim,
|
| encoder_depth,
|
| encoder_num_heads,
|
| encoder_global_attn_indexes,
|
| checkpoint=None,
|
| ):
|
| prompt_embed_dim = 256
|
| image_size = 1024
|
| vit_patch_size = 16
|
| image_embedding_size = image_size // vit_patch_size
|
| image_encoder=ImageEncoderViT(
|
| depth=encoder_depth,
|
| embed_dim=encoder_embed_dim,
|
| img_size=image_size,
|
| mlp_ratio=4,
|
| norm_layer=partial(torch.nn.LayerNorm, eps=1e-6),
|
| num_heads=encoder_num_heads,
|
| patch_size=vit_patch_size,
|
| qkv_bias=True,
|
| use_rel_pos=True,
|
| global_attn_indexes=encoder_global_attn_indexes,
|
| window_size=14,
|
| out_chans=prompt_embed_dim,
|
| )
|
| image_encoder.eval()
|
| if checkpoint is not None:
|
|
|
| state_dict = torch.load(checkpoint)
|
|
|
|
|
|
|
|
|
|
|
|
|
| image_encoder.load_state_dict({k[30:]: v for k, v in state_dict.items() if 'vision_tower_high' in k}, strict=True)
|
| print(checkpoint)
|
| return image_encoder |