| import torch.nn as nn |
| import torch |
| import torch.nn.functional as F |
| import copy |
|
|
|
|
| from typing import Optional, Tuple |
|
|
| |
|
|
| import transformers |
|
|
|
|
| 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 CustomQwen2Decoder(nn.Module): |
| """ |
| Qwen2 visual encoder |
| non-causal attention + causal attention |
| token_type_ids :0=non-causal, 1=causal |
| """ |
| |
| def __init__( |
| self, |
| decoder_layer: int = 24, |
| max_position_embeddings: int = 131072, |
| hidden_dimension: int = 896, |
| num_attention_heads: int = 14, |
| num_key_value_heads: int = 2, |
| intermediate_size: int = 4864, |
| vocab_size: int = 151936, |
| attn_implementation: str = "sdpa", |
| rms_norm_eps: float = 1e-06, |
| rope_theta: float = 1000000.0, |
| attention_dropout: float = 0.0, |
| hidden_act: str = "silu", |
| initializer_range: float = 0.02, |
| ): |
| super().__init__() |
| |
| |
| if attn_implementation == "flash_attention_2": |
| raise ValueError( |
| "CustomQwen2Decoder do not support flash_attention_2," |
| "new attention mask needs 'sdpa' or 'eager'" |
| ) |
| |
| |
| Qwen2Model = getattr(transformers.models.qwen2.modeling_qwen2, 'Qwen2Model') |
| Qwen2Config = getattr(transformers, 'Qwen2Config') |
| |
| |
| config = Qwen2Config( |
| hidden_size=hidden_dimension, |
| num_hidden_layers=decoder_layer, |
| num_attention_heads=num_attention_heads, |
| num_key_value_heads=num_key_value_heads, |
| intermediate_size=intermediate_size, |
| max_position_embeddings=max_position_embeddings, |
| vocab_size=vocab_size, |
| rms_norm_eps=rms_norm_eps, |
| rope_theta=rope_theta, |
| attention_dropout=attention_dropout, |
| hidden_act=hidden_act, |
| initializer_range=initializer_range, |
| _attn_implementation=attn_implementation, |
| ) |
| |
| |
| self.model = self._create_custom_model(Qwen2Model, config) |
|
|
| del self.model.embed_tokens |
| |
| def _create_custom_model(self, Qwen2Model, config): |
| """ Qwen2Model """ |
| |
| class CustomQwen2ModelInner(Qwen2Model): |
|
|
| |
| def forward( |
| self, |
| input_ids=None, |
| attention_mask=None, |
| position_ids=None, |
| past_key_values=None, |
| inputs_embeds=None, |
| token_type_ids=None, |
| use_cache=None, |
| output_attentions=None, |
| output_hidden_states=None, |
| return_dict=None, |
| cache_position=None, |
| ): |
| |
| self._current_token_type_ids = token_type_ids |
| |
| outputs = super().forward( |
| input_ids=input_ids, |
| attention_mask=attention_mask, |
| position_ids=position_ids, |
| past_key_values=past_key_values, |
| inputs_embeds=inputs_embeds, |
| use_cache=use_cache, |
| output_attentions=output_attentions, |
| output_hidden_states=output_hidden_states, |
| return_dict=return_dict, |
| cache_position=cache_position, |
| ) |
| |
| return outputs |
| |
| def _update_causal_mask( |
| self, |
| attention_mask, |
| input_tensor, |
| cache_position, |
| past_key_values, |
| output_attentions, |
| ): |
| dtype, device = input_tensor.dtype, input_tensor.device |
| min_dtype = torch.finfo(dtype).min |
| batch_size, sequence_length = input_tensor.shape[0], input_tensor.shape[1] |
| |
| token_type_ids = self._current_token_type_ids |
| |
| |
| causal_mask = self._create_custom_4d_mask( |
| sequence_length=sequence_length, |
| dtype=dtype, |
| device=device, |
| batch_size=batch_size, |
| token_type_ids=token_type_ids, |
| ) |
| |
| |
| if attention_mask is not None and attention_mask.dim() == 2: |
| padding_mask = attention_mask[:, None, None, :].to(dtype=dtype) |
| padding_mask = (1.0 - padding_mask) * min_dtype |
| causal_mask = causal_mask + padding_mask |
| |
| return causal_mask |
| |
| def _create_custom_4d_mask( |
| self, |
| sequence_length, |
| dtype, |
| device, |
| batch_size, |
| token_type_ids, |
| ): |
| min_dtype = torch.finfo(dtype).min |
| |
| masks = [] |
| for b in range(batch_size): |
| mask = torch.full( |
| (sequence_length, sequence_length), |
| fill_value=min_dtype, |
| dtype=dtype, |
| device=device |
| ) |
| |
| type_ids = token_type_ids[b] |
| |
| image_positions = (type_ids == 0).nonzero(as_tuple=True)[0] |
| text_positions = (type_ids == 1).nonzero(as_tuple=True)[0] |
| |
| |
| if len(image_positions) > 0: |
| mask[image_positions[:, None], image_positions] = 0.0 |
| |
| |
| for i, text_pos in enumerate(text_positions): |
| if len(image_positions) > 0: |
| mask[text_pos, image_positions] = 0.0 |
| mask[text_pos, text_positions[:i+1]] = 0.0 |
| |
| masks.append(mask) |
| |
| mask = torch.stack(masks, dim=0).unsqueeze(1) |
| return mask |
| |
| return CustomQwen2ModelInner(config) |
| |
| def forward( |
| self, |
| inputs_embeds, |
| token_type_ids, |
| attention_mask=None, |
| **kwargs |
| ): |
| """ |
| Args: |
| inputs_embeds: [batch_size, seq_len, hidden_dim] |
| token_type_ids: [batch_size, seq_len], 0=non-causal, 1=causal |
| attention_mask: [batch_size, seq_len], optional |
| """ |
| return self.model( |
| inputs_embeds=inputs_embeds, |
| token_type_ids=token_type_ids, |
| attention_mask=attention_mask, |
| **kwargs |
| ) |
|
|
|
|
|
|
|
|
|
|
| |
| |
|
|
| |
| |
| |
| |
| |
|
|
| |
| |
| |
| |
| |
|
|
|
|
|
|
| class Qwen2Decoder2Encoder(nn.Module): |
| """ |
| Decoder based on Multilingual BART |
| Set the initial weights and configuration with a pretrained multilingual BART model, |
| and modify the detailed configurations as a Nougat decoder |
| """ |
|
|
| def __init__( |
| self, |
| decoder_layer: int, |
| hidden_dimension: int, |
| num_attention_heads: int, |
| num_key_value_heads: int, |
| intermediate_size: int, |
| max_query: int, |
| ): |
| super().__init__() |
|
|
| self.model = CustomQwen2Decoder( |
| decoder_layer=decoder_layer, |
| hidden_dimension=hidden_dimension, |
| num_attention_heads=num_attention_heads, |
| num_key_value_heads=num_key_value_heads, |
| intermediate_size=intermediate_size, |
| attn_implementation="sdpa", |
| ) |
|
|
|
|
|
|
|
|
| self.query_768 = nn.Embedding(144, hidden_dimension) |
| self.query_1024 = nn.Embedding(256, hidden_dimension) |
|
|
|
|
| |
|
|
|
|
| def forward(self, x: torch.Tensor) -> torch.Tensor: |
| x = x.flatten(2).transpose(1, 2) |
|
|
| bs, n_query, _ = x.shape |
|
|
| if n_query == 144: |
| param_img = self.query_768.weight |
| elif n_query == 256: |
| param_img = self.query_1024.weight |
|
|
| batch_query_imgs = param_img.unsqueeze(0).expand( |
| bs, -1, -1 |
| ) |
|
|
|
|
|
|
| x_combined = torch.cat([x, batch_query_imgs], dim=1) |
|
|
| token_type_ids = torch.cat([ |
| torch.zeros(bs, n_query, dtype=torch.long), |
| torch.ones(bs, n_query, dtype=torch.long), |
| ], dim=1) |
|
|
|
|
| y = self.model(x_combined, token_type_ids)[0] |
|
|
|
|
| y = y[:, n_query:, :] |
|
|
|
|
| return y |
|
|
|
|
| def build_qwen2_decoder_as_encoder( |
| decoder_layer=24, |
| hidden_dimension=896, |
| num_attention_heads=14, |
| num_key_value_heads=2, |
| intermediate_size=4864, |
| max_query = 400, |
| checkpoint=None, |
| ): |
|
|
| decoder_as_encoder = Qwen2Decoder2Encoder( |
| decoder_layer=decoder_layer, |
| hidden_dimension = hidden_dimension, |
| num_attention_heads = num_attention_heads, |
| num_key_value_heads = num_key_value_heads, |
| intermediate_size = intermediate_size, |
| max_query = max_query |
| ) |
|
|
|
|
|
|
| |
| if checkpoint is not None: |
| |
| state_dict = torch.load(checkpoint) |
|
|
| decoder_as_encoder.load_state_dict(state_dict, strict=True) |
| |
| print(checkpoint) |
| return decoder_as_encoder |
|
|
|
|
|
|
|
|
| |
|
|
|
|
| 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, 896, 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 |