# Copyright 2023 The Intel Labs Team Authors, The Microsoft Research Team Authors and HuggingFace Inc. team. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """PyTorch BridgeTower Model""" from collections import OrderedDict from collections.abc import Callable from dataclasses import dataclass import torch from torch import nn from torch.nn import CrossEntropyLoss from ... import initialization as init from ...activations import ACT2FN, QuickGELUActivation from ...cache_utils import Cache, DynamicCache, EncoderDecoderCache from ...masking_utils import create_bidirectional_mask, create_causal_mask from ...modeling_layers import GradientCheckpointingLayer from ...modeling_outputs import ( BaseModelOutputWithPastAndCrossAttentions, BaseModelOutputWithPoolingAndCrossAttentions, MaskedLMOutput, ModelOutput, SequenceClassifierOutput, ) from ...modeling_utils import ALL_ATTENTION_FUNCTIONS, PreTrainedModel from ...processing_utils import Unpack from ...pytorch_utils import apply_chunking_to_forward from ...utils import TransformersKwargs, auto_docstring, logging, torch_int from ...utils.generic import can_return_tuple from .configuration_bridgetower import BridgeTowerConfig, BridgeTowerTextConfig, BridgeTowerVisionConfig logger = logging.get_logger(__name__) _TOKENIZER_FOR_DOC = "RobertaTokenizer" @dataclass @auto_docstring( custom_intro=""" Output type of [`BridgeTowerModel`]. """ ) class BridgeTowerModelOutput(ModelOutput): r""" text_features (`torch.FloatTensor` of shape `(batch_size, text_sequence_length, hidden_size)`): Sequence of hidden-states at the text output of the last layer of the model. image_features (`torch.FloatTensor` of shape `(batch_size, image_sequence_length, hidden_size)`): Sequence of hidden-states at the image output of the last layer of the model. pooler_output (`torch.FloatTensor` of shape `(batch_size, hidden_size x 2)`): Concatenation of last layer hidden-state of the first token of the text and image sequence (classification token), respectively, after further processing through layers used for auxiliary pretraining tasks. """ text_features: torch.FloatTensor | None = None image_features: torch.FloatTensor | None = None pooler_output: torch.FloatTensor | None = None hidden_states: tuple[torch.FloatTensor] | None = None attentions: tuple[torch.FloatTensor] | None = None @dataclass @auto_docstring( custom_intro=""" Output type of ['BridgeTowerForContrastiveLearning'] """ ) class BridgeTowerContrastiveOutput(ModelOutput): r""" loss (`torch.FloatTensor` of shape `(1,)`, *optional*, returned when `return_loss` is `True`): Image-text contrastive loss. logits (`torch.FloatTensor` of shape `(batch_size, sequence_length, config.vocab_size)`): Prediction scores of the language modeling head (scores for each vocabulary token before SoftMax). text_embeds (`torch.FloatTensor)`, *optional*, returned when model is initialized with `with_projection=True`): The text embeddings obtained by applying the projection layer to the pooler_output. image_embeds (`torch.FloatTensor)`, *optional*, returned when model is initialized with `with_projection=True`): The image embeddings obtained by applying the projection layer to the pooler_output. cross_embeds (`torch.FloatTensor)`, *optional*, returned when model is initialized with `with_projection=True`): The text-image cross-modal embeddings obtained by applying the projection layer to the pooler_output. attentions (`tuple(torch.FloatTensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`): Tuple of `torch.FloatTensor` (one for each layer) of shape `(batch_size, num_heads, sequence_length, sequence_length)`. """ loss: torch.FloatTensor | None = None logits: torch.FloatTensor | None = None text_embeds: tuple[torch.FloatTensor] | None = None image_embeds: tuple[torch.FloatTensor] | None = None cross_embeds: tuple[torch.FloatTensor] | None = None hidden_states: tuple[torch.FloatTensor] | None = None attentions: tuple[torch.FloatTensor] | None = None class BridgeTowerResidualAttention(nn.Module): def __init__(self, config): super().__init__() self.attn = nn.MultiheadAttention(config.hidden_size, config.hidden_size // 64) self.ln_1 = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.mlp = nn.ModuleDict( OrderedDict( [ ("c_fc", nn.Linear(config.hidden_size, config.hidden_size * 4)), ("gelu", QuickGELUActivation()), ("c_proj", nn.Linear(config.hidden_size * 4, config.hidden_size)), ] ) ) self.ln_2 = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.attn_mask = None def attention(self, hidden_state: torch.Tensor, attention_mask: torch.Tensor): if attention_mask is not None: attention_mask = attention_mask.to(dtype=torch.bool, device=hidden_state.device) self.attn_mask = ( self.attn_mask.to(dtype=hidden_state.dtype, device=hidden_state.device) if self.attn_mask is not None else None ) return self.attn( hidden_state, hidden_state, hidden_state, need_weights=False, attn_mask=self.attn_mask, key_padding_mask=attention_mask, )[0] def forward(self, hidden_state: torch.Tensor, attention_mask: torch.Tensor | None = None): residual_state = hidden_state + self.attention(self.ln_1(hidden_state), attention_mask) hidden_state = self.ln_2(residual_state) for layer in self.mlp.values(): hidden_state = layer(hidden_state) hidden_state = residual_state + hidden_state return hidden_state class BridgeTowerTransformer(nn.Module): def __init__(self, config): super().__init__() self.hidden_size = config.hidden_size self.num_hidden_layers = config.num_hidden_layers if config.remove_last_layer: self.resblocks = nn.ModuleList( [BridgeTowerResidualAttention(config) for _ in range(self.num_hidden_layers - 1)] ) else: self.resblocks = nn.ModuleList( [BridgeTowerResidualAttention(config) for _ in range(self.num_hidden_layers)] ) self.stop_gradient = config.stop_gradient def forward(self, hidden_state: torch.Tensor, attention_mask: torch.Tensor | None = None): hidden_states = [] for block in self.resblocks: hidden_state = block(hidden_state, attention_mask) if self.stop_gradient: hidden_states.append(hidden_state.detach()) else: hidden_states.append(hidden_state) return hidden_states # Copied from transformers.models.clip.modeling_clip.CLIPVisionEmbeddings with CLIP->BridgeTower class BridgeTowerVisionEmbeddings(nn.Module): def __init__(self, config: BridgeTowerVisionConfig): super().__init__() self.config = config self.embed_dim = config.hidden_size self.image_size = config.image_size self.patch_size = config.patch_size self.class_embedding = nn.Parameter(torch.randn(self.embed_dim)) self.patch_embedding = nn.Conv2d( in_channels=config.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 = nn.Embedding(self.num_positions, self.embed_dim) self.register_buffer("position_ids", torch.arange(self.num_positions).expand((1, -1)), persistent=False) def interpolate_pos_encoding(self, embeddings: torch.Tensor, height: int, width: int) -> torch.Tensor: """ This method allows to interpolate the pre-trained position encodings, to be able to use the model on higher resolution images. This method is also adapted to support torch.jit tracing. Adapted from: - https://github.com/facebookresearch/dino/blob/de9ee3df6cf39fac952ab558447af1fa1365362a/vision_transformer.py#L174-L194, and - https://github.com/facebookresearch/dinov2/blob/e1277af2ba9496fbadf7aec6eba56e8d882d1e35/dinov2/models/vision_transformer.py#L179-L211 """ num_patches = embeddings.shape[1] - 1 position_embedding = self.position_embedding.weight.unsqueeze(0) num_positions = position_embedding.shape[1] - 1 # always interpolate when tracing to ensure the exported model works for dynamic input shapes if not torch.jit.is_tracing() and num_patches == num_positions and height == width: return self.position_embedding(self.position_ids) class_pos_embed = position_embedding[:, :1] patch_pos_embed = position_embedding[:, 1:] dim = embeddings.shape[-1] new_height = height // self.patch_size new_width = width // self.patch_size sqrt_num_positions = torch_int(num_positions**0.5) patch_pos_embed = patch_pos_embed.reshape(1, sqrt_num_positions, sqrt_num_positions, dim) patch_pos_embed = patch_pos_embed.permute(0, 3, 1, 2) patch_pos_embed = nn.functional.interpolate( patch_pos_embed, size=(new_height, new_width), mode="bicubic", align_corners=False, ) patch_pos_embed = patch_pos_embed.permute(0, 2, 3, 1).view(1, -1, dim) return torch.cat((class_pos_embed, patch_pos_embed), dim=1) def forward(self, pixel_values: torch.FloatTensor, interpolate_pos_encoding=False) -> torch.Tensor: batch_size, _, height, width = pixel_values.shape if not interpolate_pos_encoding and (height != self.image_size or width != self.image_size): raise ValueError( f"Input image size ({height}*{width}) doesn't match model ({self.image_size}*{self.image_size})." ) target_dtype = self.patch_embedding.weight.dtype patch_embeds = self.patch_embedding(pixel_values.to(dtype=target_dtype)) # shape = [*, width, grid, grid] 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) if interpolate_pos_encoding: embeddings = embeddings + self.interpolate_pos_encoding(embeddings, height, width) else: embeddings = embeddings + self.position_embedding(self.position_ids) return embeddings class BridgeTowerVisionTransformer(nn.Module): def __init__(self, config): super().__init__() self.embeddings = BridgeTowerVisionEmbeddings(config) self.ln_pre = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.transformer = BridgeTowerTransformer(config) self.ln_post = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.share_layernorm = config.share_layernorm if not config.share_layernorm: self.ln_separate = nn.ModuleList( [nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) for _ in range(config.num_hidden_layers)] ) def forward( self, pixel_values: torch.Tensor, attention_mask, interpolate_pos_encoding: bool = False, ): hidden_states = self.embeddings(pixel_values, interpolate_pos_encoding) hidden_states = self.ln_pre(hidden_states) # NLD -> LND hidden_states = hidden_states.permute(1, 0, 2) hidden_states = self.transformer(hidden_states, attention_mask) # shape = [num_hidden_layers, hidden_size, *, grid ** 2] hidden_states = torch.stack(hidden_states, dim=0) # shape = [num_hidden_layers, *, hidden_size, grid ** 2] hidden_states = hidden_states.permute(0, 2, 1, 3) if self.share_layernorm: hidden_states = self.ln_post(hidden_states) else: hidden_states_stack = [] for hidden_states, ln in zip(hidden_states, self.ln_separate): hidden_states = ln(hidden_states) hidden_states_stack.append(hidden_states) # shape = [num_hidden_layers, *, hidden_size, grid ** 2] hidden_states = torch.stack(hidden_states_stack, dim=0) return hidden_states def forward_pre( self, pixel_values: torch.Tensor, interpolate_pos_encoding: bool = False, ): hidden_states = self.embeddings(pixel_values, interpolate_pos_encoding=interpolate_pos_encoding) hidden_states = self.ln_pre(hidden_states) # NLD -> LND hidden_states = hidden_states.permute(1, 0, 2) return hidden_states def forward_post(self, hidden_state: torch.Tensor): visual_output_post = hidden_state.permute(1, 0, 2) visual_output_post = self.ln_post(visual_output_post) return visual_output_post class BridgeTowerLinkTower(nn.Module): def __init__(self, config): super().__init__() self.link_tower_type = config.link_tower_type self.hidden_size = config.hidden_size if config.link_tower_type in ["add", "scaled_add", "interpolate"]: if config.link_tower_type == "scaled_add": self.scaled_factor = nn.Parameter(torch.tensor(1.0)) elif config.link_tower_type == "interpolate": self.beta = nn.Parameter(torch.tensor(0.5)) self.LayerNorm = nn.LayerNorm(self.hidden_size, eps=config.layer_norm_eps) else: raise NotImplementedError(f"link_tower_type {config.link_tower_type} is not implemented") def forward(self, hidden_states, cross_modal_hidden_states, attention_mask): if self.link_tower_type == "add": return self.LayerNorm(hidden_states + cross_modal_hidden_states) elif self.link_tower_type == "scaled_add": return self.LayerNorm(hidden_states * self.scaled_factor + cross_modal_hidden_states) elif self.link_tower_type == "interpolate": return self.LayerNorm(hidden_states * (1 - self.beta) + cross_modal_hidden_states * self.beta) else: raise NotImplementedError(f"link_tower_type {self.link_tower_type} is not implemented") # Copied from transformers.models.bert.modeling_bert.BertSelfOutput with Bert->BridgeTower class BridgeTowerSelfOutput(nn.Module): def __init__(self, config): super().__init__() self.dense = nn.Linear(config.hidden_size, config.hidden_size) self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.dropout = nn.Dropout(config.hidden_dropout_prob) def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor: hidden_states = self.dense(hidden_states) hidden_states = self.dropout(hidden_states) hidden_states = self.LayerNorm(hidden_states + input_tensor) return hidden_states # Copied from transformers.models.bert.modeling_bert.BertIntermediate with Bert->BridgeTower class BridgeTowerIntermediate(nn.Module): def __init__(self, config): super().__init__() self.dense = nn.Linear(config.hidden_size, config.intermediate_size) if isinstance(config.hidden_act, str): self.intermediate_act_fn = ACT2FN[config.hidden_act] else: self.intermediate_act_fn = config.hidden_act def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: hidden_states = self.dense(hidden_states) hidden_states = self.intermediate_act_fn(hidden_states) return hidden_states # Copied from transformers.models.bert.modeling_bert.BertOutput with Bert->BridgeTower class BridgeTowerOutput(nn.Module): def __init__(self, config): super().__init__() self.dense = nn.Linear(config.intermediate_size, config.hidden_size) self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.dropout = nn.Dropout(config.hidden_dropout_prob) def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor: hidden_states = self.dense(hidden_states) hidden_states = self.dropout(hidden_states) hidden_states = self.LayerNorm(hidden_states + input_tensor) return hidden_states # Copied from transformers.models.bert.modeling_bert.BertPooler with Bert->BridgeTower class BridgeTowerPooler(nn.Module): def __init__(self, config): super().__init__() self.dense = nn.Linear(config.hidden_size, config.hidden_size) self.activation = nn.Tanh() def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: # We "pool" the model by simply taking the hidden state corresponding # to the first token. first_token_tensor = hidden_states[:, 0] pooled_output = self.dense(first_token_tensor) pooled_output = self.activation(pooled_output) return pooled_output # Copied from transformers.models.bert.modeling_bert.eager_attention_forward def eager_attention_forward( module: nn.Module, query: torch.Tensor, key: torch.Tensor, value: torch.Tensor, attention_mask: torch.Tensor | None, scaling: float | None = None, dropout: float = 0.0, **kwargs: Unpack[TransformersKwargs], ): if scaling is None: scaling = query.size(-1) ** -0.5 # Take the dot product between "query" and "key" to get the raw attention scores. attn_weights = torch.matmul(query, key.transpose(2, 3)) * scaling if attention_mask is not None: attention_mask = attention_mask[:, :, :, : key.shape[-2]] attn_weights = attn_weights + attention_mask attn_weights = nn.functional.softmax(attn_weights, dim=-1) attn_weights = nn.functional.dropout(attn_weights, p=dropout, training=module.training) attn_output = torch.matmul(attn_weights, value) attn_output = attn_output.transpose(1, 2).contiguous() return attn_output, attn_weights # Copied from transformers.models.roberta.modeling_roberta.RobertaSelfAttention with Roberta->BridgeTower class BridgeTowerSelfAttention(nn.Module): def __init__(self, config, is_causal=False, layer_idx=None): super().__init__() if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"): raise ValueError( f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention " f"heads ({config.num_attention_heads})" ) self.config = config self.num_attention_heads = config.num_attention_heads self.attention_head_size = int(config.hidden_size / config.num_attention_heads) self.all_head_size = self.num_attention_heads * self.attention_head_size self.scaling = self.attention_head_size**-0.5 self.query = nn.Linear(config.hidden_size, self.all_head_size) self.key = nn.Linear(config.hidden_size, self.all_head_size) self.value = nn.Linear(config.hidden_size, self.all_head_size) self.dropout = nn.Dropout(config.attention_probs_dropout_prob) self.is_decoder = config.is_decoder self.is_causal = is_causal self.layer_idx = layer_idx def forward( self, hidden_states: torch.Tensor, attention_mask: torch.FloatTensor | None = None, past_key_values: Cache | None = None, cache_position: torch.Tensor | None = None, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor]: input_shape = hidden_states.shape[:-1] hidden_shape = (*input_shape, -1, self.attention_head_size) # get all proj query_layer = self.query(hidden_states).view(*hidden_shape).transpose(1, 2) key_layer = self.key(hidden_states).view(*hidden_shape).transpose(1, 2) value_layer = self.value(hidden_states).view(*hidden_shape).transpose(1, 2) if past_key_values is not None: # decoder-only roberta can have a simple dynamic cache for example current_past_key_values = past_key_values if isinstance(past_key_values, EncoderDecoderCache): current_past_key_values = past_key_values.self_attention_cache # save all key/value_layer to cache to be re-used for fast auto-regressive generation key_layer, value_layer = current_past_key_values.update( key_layer, value_layer, self.layer_idx, {"cache_position": cache_position}, ) attention_interface: Callable = ALL_ATTENTION_FUNCTIONS.get_interface( self.config._attn_implementation, eager_attention_forward ) attn_output, attn_weights = attention_interface( self, query_layer, key_layer, value_layer, attention_mask, dropout=0.0 if not self.training else self.dropout.p, scaling=self.scaling, **kwargs, ) attn_output = attn_output.reshape(*input_shape, -1).contiguous() return attn_output, attn_weights # Copied from transformers.models.roberta.modeling_roberta.RobertaCrossAttention with Roberta->BridgeTower class BridgeTowerCrossAttention(nn.Module): def __init__(self, config, is_causal=False, layer_idx=None): super().__init__() if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"): raise ValueError( f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention " f"heads ({config.num_attention_heads})" ) self.config = config self.num_attention_heads = config.num_attention_heads self.attention_head_size = int(config.hidden_size / config.num_attention_heads) self.all_head_size = self.num_attention_heads * self.attention_head_size self.scaling = self.attention_head_size**-0.5 self.query = nn.Linear(config.hidden_size, self.all_head_size) self.key = nn.Linear(config.hidden_size, self.all_head_size) self.value = nn.Linear(config.hidden_size, self.all_head_size) self.dropout = nn.Dropout(config.attention_probs_dropout_prob) self.is_causal = is_causal self.layer_idx = layer_idx def forward( self, hidden_states: torch.Tensor, encoder_hidden_states: torch.FloatTensor | None = None, attention_mask: torch.FloatTensor | None = None, past_key_values: EncoderDecoderCache | None = None, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor]: # determine input shapes bsz, tgt_len = hidden_states.shape[:-1] src_len = encoder_hidden_states.shape[1] q_input_shape = (bsz, tgt_len, -1, self.attention_head_size) kv_input_shape = (bsz, src_len, -1, self.attention_head_size) # get query proj query_layer = self.query(hidden_states).view(*q_input_shape).transpose(1, 2) is_updated = past_key_values.is_updated.get(self.layer_idx) if past_key_values is not None else False if past_key_values is not None and is_updated: # reuse k,v, cross_attentions key_layer = past_key_values.cross_attention_cache.layers[self.layer_idx].keys value_layer = past_key_values.cross_attention_cache.layers[self.layer_idx].values else: key_layer = self.key(encoder_hidden_states).view(*kv_input_shape).transpose(1, 2) value_layer = self.value(encoder_hidden_states).view(*kv_input_shape).transpose(1, 2) if past_key_values is not None: # save all states to the cache key_layer, value_layer = past_key_values.cross_attention_cache.update( key_layer, value_layer, self.layer_idx ) # set flag that curr layer for cross-attn is already updated so we can re-use in subsequent calls past_key_values.is_updated[self.layer_idx] = True attention_interface: Callable = ALL_ATTENTION_FUNCTIONS.get_interface( self.config._attn_implementation, eager_attention_forward ) attn_output, attn_weights = attention_interface( self, query_layer, key_layer, value_layer, attention_mask, dropout=0.0 if not self.training else self.dropout.p, scaling=self.scaling, **kwargs, ) attn_output = attn_output.reshape(bsz, tgt_len, -1).contiguous() return attn_output, attn_weights # Copied from transformers.models.bert.modeling_bert.BertAttention with Bert->BridgeTower,BERT->BRIDGE_TOWER class BridgeTowerAttention(nn.Module): def __init__(self, config, is_causal=False, layer_idx=None, is_cross_attention=False): super().__init__() self.is_cross_attention = is_cross_attention attention_class = BridgeTowerCrossAttention if is_cross_attention else BridgeTowerSelfAttention self.self = attention_class(config, is_causal=is_causal, layer_idx=layer_idx) self.output = BridgeTowerSelfOutput(config) def forward( self, hidden_states: torch.Tensor, attention_mask: torch.FloatTensor | None = None, encoder_hidden_states: torch.FloatTensor | None = None, encoder_attention_mask: torch.FloatTensor | None = None, past_key_values: Cache | None = None, cache_position: torch.Tensor | None = None, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor]: attention_mask = attention_mask if not self.is_cross_attention else encoder_attention_mask attention_output, attn_weights = self.self( hidden_states, encoder_hidden_states=encoder_hidden_states, attention_mask=attention_mask, past_key_values=past_key_values, cache_position=cache_position, **kwargs, ) attention_output = self.output(attention_output, hidden_states) return attention_output, attn_weights class BridgeTowerBertCrossLayer(nn.Module): def __init__(self, config, layer_idx=None): super().__init__() self.chunk_size_feed_forward = config.chunk_size_feed_forward self.seq_len_dim = 1 self.attention = BridgeTowerAttention(config, is_causal=True, layer_idx=layer_idx) self.is_decoder = config.is_decoder self.add_cross_attention = config.add_cross_attention self.crossattention = BridgeTowerAttention( config, is_causal=False, layer_idx=layer_idx, is_cross_attention=True, ) self.intermediate = BridgeTowerIntermediate(config) self.output = BridgeTowerOutput(config) def forward( self, hidden_states, encoder_hidden_states, attention_mask=None, encoder_attention_mask=None, past_key_values=None, **kwargs: Unpack[TransformersKwargs], ): self_attention_output, self_attn_weights = self.attention( hidden_states, attention_mask=attention_mask, past_key_values=None, **kwargs, ) attention_output = self_attention_output cross_attention_output, cross_attn_weights = self.crossattention( attention_output, attention_mask=attention_mask, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, past_key_values=past_key_values, **kwargs, ) attention_output = cross_attention_output layer_output = apply_chunking_to_forward( self.feed_forward_chunk, self.chunk_size_feed_forward, self.seq_len_dim, attention_output ) return ( layer_output, self_attn_weights, cross_attn_weights, ) def feed_forward_chunk(self, attention_output): intermediate_output = self.intermediate(attention_output) layer_output = self.output(intermediate_output, attention_output) return layer_output class BridgeTowerTextLayer(GradientCheckpointingLayer): def __init__(self, config, layer_idx=None): super().__init__() self.chunk_size_feed_forward = config.chunk_size_feed_forward self.seq_len_dim = 1 self.attention = BridgeTowerAttention(config, is_causal=config.is_decoder, layer_idx=layer_idx) self.is_decoder = config.is_decoder self.add_cross_attention = config.add_cross_attention if self.add_cross_attention: if not self.is_decoder: raise ValueError(f"{self} should be used as a decoder model if cross attention is added") self.crossattention = BridgeTowerAttention( config, is_causal=False, layer_idx=layer_idx, is_cross_attention=True, ) self.intermediate = BridgeTowerIntermediate(config) self.output = BridgeTowerOutput(config) # copied from transformers.models.bert.modeling_bert.BertLayer.forward def forward( self, hidden_states: torch.Tensor, attention_mask: torch.FloatTensor | None = None, encoder_hidden_states: torch.FloatTensor | None = None, encoder_attention_mask: torch.FloatTensor | None = None, past_key_values: Cache | None = None, cache_position: torch.Tensor | None = None, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor]: outputs = () self_attention_output, self_attn_weights = self.attention( hidden_states, attention_mask, past_key_values=past_key_values, cache_position=cache_position, **kwargs, ) attention_output = self_attention_output if self.is_decoder and encoder_hidden_states is not None: if not hasattr(self, "crossattention"): raise ValueError( f"If `encoder_hidden_states` are passed, {self} has to be instantiated with cross-attention layers" " by setting `config.add_cross_attention=True`" ) cross_attention_output, cross_attn_weights = self.crossattention( self_attention_output, None, # attention_mask encoder_hidden_states, encoder_attention_mask, past_key_values=past_key_values, **kwargs, ) attention_output = cross_attention_output outputs = (cross_attn_weights,) layer_output = apply_chunking_to_forward( self.feed_forward_chunk, self.chunk_size_feed_forward, self.seq_len_dim, attention_output ) return outputs + ( layer_output, self_attn_weights, ) def feed_forward_chunk(self, attention_output): intermediate_output = self.intermediate(attention_output) layer_output = self.output(intermediate_output, attention_output) return layer_output # copied from transformers.models.roberta.modeling_roberta.RobertaEncoder with Roberta->BridgeTowerText class BridgeTowerTextEncoder(nn.Module): def __init__(self, config): super().__init__() self.config = config self.layer = nn.ModuleList( [BridgeTowerTextLayer(config, layer_idx=i) for i in range(config.num_hidden_layers)] ) def forward( self, hidden_states: torch.Tensor, attention_mask: torch.FloatTensor | None = None, encoder_hidden_states: torch.FloatTensor | None = None, encoder_attention_mask: torch.FloatTensor | None = None, past_key_values: Cache | None = None, use_cache: bool | None = None, output_attentions: bool | None = False, output_hidden_states: bool | None = False, cache_position: torch.Tensor | None = None, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor] | BaseModelOutputWithPastAndCrossAttentions: all_hidden_states = () if output_hidden_states else None all_self_attentions = () if output_attentions else None all_cross_attentions = () if output_attentions and self.config.add_cross_attention else None for i, layer_module in enumerate(self.layer): layer_outputs = layer_module( hidden_states, attention_mask, encoder_hidden_states, # as a positional argument for gradient checkpointing encoder_attention_mask=encoder_attention_mask, past_key_values=past_key_values, cache_position=cache_position, **kwargs, ) hidden_states = layer_outputs[0] if output_attentions: all_self_attentions = all_self_attentions + (layer_outputs[1],) if self.config.add_cross_attention: all_cross_attentions = all_cross_attentions + (layer_outputs[2],) if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) return BaseModelOutputWithPastAndCrossAttentions( last_hidden_state=hidden_states, past_key_values=past_key_values if use_cache else None, hidden_states=all_hidden_states, attentions=all_self_attentions, cross_attentions=all_cross_attentions, ) # Copied from transformers.models.roberta.modeling_roberta.RobertaEmbeddings with Roberta->BridgeTowerText class BridgeTowerTextEmbeddings(nn.Module): """Construct the embeddings from word, position and token_type embeddings.""" def __init__(self, config): super().__init__() self.word_embeddings = nn.Embedding(config.vocab_size, config.hidden_size, padding_idx=config.pad_token_id) self.token_type_embeddings = nn.Embedding(config.type_vocab_size, config.hidden_size) self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.dropout = nn.Dropout(config.hidden_dropout_prob) # position_ids (1, len position emb) is contiguous in memory and exported when serialized self.register_buffer( "position_ids", torch.arange(config.max_position_embeddings).expand((1, -1)), persistent=False ) self.register_buffer( "token_type_ids", torch.zeros(self.position_ids.size(), dtype=torch.long), persistent=False ) self.padding_idx = config.pad_token_id self.position_embeddings = nn.Embedding( config.max_position_embeddings, config.hidden_size, padding_idx=self.padding_idx ) def forward( self, input_ids: torch.LongTensor | None = None, token_type_ids: torch.LongTensor | None = None, position_ids: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, past_key_values_length: int = 0, ) -> torch.Tensor: if position_ids is None: if input_ids is not None: # Create the position ids from the input token ids. Any padded tokens remain padded. position_ids = self.create_position_ids_from_input_ids( input_ids, self.padding_idx, past_key_values_length ) else: position_ids = self.create_position_ids_from_inputs_embeds(inputs_embeds, self.padding_idx) if input_ids is not None: input_shape = input_ids.size() else: input_shape = inputs_embeds.size()[:-1] batch_size, seq_length = input_shape # Setting the token_type_ids to the registered buffer in constructor where it is all zeros, which usually occurs # when its auto-generated, registered buffer helps users when tracing the model without passing token_type_ids, solves # issue #5664 if token_type_ids is None: if hasattr(self, "token_type_ids"): # NOTE: We assume either pos ids to have bsz == 1 (broadcastable) or bsz == effective bsz (input_shape[0]) buffered_token_type_ids = self.token_type_ids.expand(position_ids.shape[0], -1) buffered_token_type_ids = torch.gather(buffered_token_type_ids, dim=1, index=position_ids) token_type_ids = buffered_token_type_ids.expand(batch_size, seq_length) else: token_type_ids = torch.zeros(input_shape, dtype=torch.long, device=self.position_ids.device) if inputs_embeds is None: inputs_embeds = self.word_embeddings(input_ids) token_type_embeddings = self.token_type_embeddings(token_type_ids) embeddings = inputs_embeds + token_type_embeddings position_embeddings = self.position_embeddings(position_ids) embeddings = embeddings + position_embeddings embeddings = self.LayerNorm(embeddings) embeddings = self.dropout(embeddings) return embeddings @staticmethod def create_position_ids_from_inputs_embeds(inputs_embeds, padding_idx): """ We are provided embeddings directly. We cannot infer which are padded so just generate sequential position ids. Args: inputs_embeds: torch.Tensor Returns: torch.Tensor """ input_shape = inputs_embeds.size()[:-1] sequence_length = input_shape[1] position_ids = torch.arange( padding_idx + 1, sequence_length + padding_idx + 1, dtype=torch.long, device=inputs_embeds.device ) return position_ids.unsqueeze(0).expand(input_shape) @staticmethod def create_position_ids_from_input_ids(input_ids, padding_idx, past_key_values_length=0): """ Replace non-padding symbols with their position numbers. Position numbers begin at padding_idx+1. Padding symbols are ignored. This is modified from fairseq's `utils.make_positions`. Args: x: torch.Tensor x: Returns: torch.Tensor """ # The series of casts and type-conversions here are carefully balanced to both work with ONNX export and XLA. mask = input_ids.ne(padding_idx).int() incremental_indices = (torch.cumsum(mask, dim=1).type_as(mask) + past_key_values_length) * mask return incremental_indices.long() + padding_idx @auto_docstring class BridgeTowerPreTrainedModel(PreTrainedModel): config: BridgeTowerConfig base_model_prefix = "bridgetower" input_modalities = ("image", "text") supports_gradient_checkpointing = False _no_split_modules = ["BridgeTowerSelfAttention", "BridgeTowerResidualAttention"] _skip_keys_device_placement = "past_key_values" @torch.no_grad() def _init_weights(self, module: nn.Module): std = self.config.initializer_factor if isinstance(module, BridgeTowerVisionTransformer): proj_std = (self.config.hidden_size**-0.5) * ((2 * self.config.num_hidden_layers) ** -0.5) attn_std = self.config.hidden_size**-0.5 fc_std = (2 * self.config.hidden_size) ** -0.5 for block in module.transformer.resblocks: init.normal_(block.attn.in_proj_weight, std=attn_std * std) init.zeros_(block.attn.in_proj_bias) init.normal_(block.attn.out_proj.weight, std=proj_std * std) init.normal_(block.mlp.c_fc.weight, std=fc_std * std) init.normal_(block.mlp.c_proj.weight, std=proj_std * std) init.normal_(module.embeddings.class_embedding, std=attn_std * std) init.normal_(module.embeddings.position_embedding.weight, std=attn_std * std) elif isinstance(module, (nn.Linear, nn.Conv2d, nn.Embedding)): init.normal_(module.weight, mean=0.0, std=0.05 * std) elif isinstance(module, nn.LayerNorm): init.zeros_(module.bias) init.ones_(module.weight) elif isinstance(module, BridgeTowerForContrastiveLearning): init.constant_(module.logit_scale, self.config.logit_scale_init_value) elif isinstance(module, BridgeTowerVisionEmbeddings): init.copy_(module.position_ids, torch.arange(module.num_positions).expand((1, -1))) elif isinstance(module, BridgeTowerTextEmbeddings): init.copy_(module.position_ids, torch.arange(module.position_ids.shape[-1]).expand((1, -1))) init.zeros_(module.token_type_ids) if isinstance(module, (nn.Linear, BridgeTowerMLMHead)) and module.bias is not None: init.zeros_(module.bias) class BridgeTowerVisionModel(BridgeTowerPreTrainedModel): config: BridgeTowerVisionConfig input_modalities = ("image",) def __init__(self, config): super().__init__(config) self.visual = BridgeTowerVisionTransformer(config) self.post_init() @property def dtype(self): return self.visual.embeddings.patch_embedding.weight.dtype def forward(self, image, image_mask=None, interpolate_pos_encoding=False, **kwargs): return self.visual(image.type(self.dtype), image_mask, interpolate_pos_encoding) @auto_docstring( custom_intro=""" The model can behave as an encoder (with only self-attention) as well as a decoder, in which case a layer of cross-attention is added between the self-attention layers, following the architecture described in *Attention is all you need*_ by Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N. Gomez, Lukasz Kaiser and Illia Polosukhin. To behave as an decoder the model needs to be initialized with the `is_decoder` argument of the configuration set to `True`. To be used in a Seq2Seq model, the model needs to initialized with both `is_decoder` argument and `add_cross_attention` set to `True`; an `encoder_hidden_states` is then expected as an input to the forward pass. .. _*Attention is all you need*: https://huggingface.co/papers/1706.03762 """ ) class BridgeTowerTextModel(BridgeTowerPreTrainedModel): config: BridgeTowerTextConfig input_modalities = ("text",) def __init__(self, config, add_pooling_layer=True): r""" add_pooling_layer (bool, *optional*, defaults to `True`): Whether to add a pooling layer """ super().__init__(config) self.config = config self.gradient_checkpointing = False self.embeddings = BridgeTowerTextEmbeddings(config) self.encoder = BridgeTowerTextEncoder(config) self.pooler = BridgeTowerPooler(config) if add_pooling_layer else None # Initialize weights and apply final processing self.post_init() def get_input_embeddings(self): return self.embeddings.word_embeddings def set_input_embeddings(self, value): self.embeddings.word_embeddings = value @can_return_tuple @auto_docstring # NOTE: bridgetower with its multimodality has a more complicated scheme making records harder # for now we skip the copies from bert but stay close to the original # copied from transformers.models.bert.modeling_bert.BertModel.forward def forward( self, input_ids: torch.Tensor | None = None, attention_mask: torch.Tensor | None = None, token_type_ids: torch.Tensor | None = None, position_ids: torch.Tensor | None = None, inputs_embeds: torch.Tensor | None = None, encoder_hidden_states: torch.Tensor | None = None, encoder_attention_mask: torch.Tensor | None = None, past_key_values: Cache | None = None, use_cache: bool | None = None, output_attentions: bool | None = None, output_hidden_states: bool | None = None, cache_position: torch.Tensor | None = None, **kwargs: Unpack[TransformersKwargs], ) -> tuple[torch.Tensor] | BaseModelOutputWithPoolingAndCrossAttentions: output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) if self.config.is_decoder: use_cache = use_cache if use_cache is not None else self.config.use_cache else: use_cache = False if self.gradient_checkpointing and self.training: if use_cache: logger.warning_once( "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..." ) use_cache = False if use_cache and past_key_values is None: past_key_values = EncoderDecoderCache(DynamicCache(config=self.config), DynamicCache(config=self.config)) if (input_ids is None) ^ (inputs_embeds is not None): raise ValueError("You must specify exactly one of input_ids or inputs_embeds") if input_ids is not None: device = input_ids.device input_shape = input_ids.shape else: device = inputs_embeds.device input_shape = inputs_embeds.shape[:-1] seq_length = input_shape[1] past_key_values_length = past_key_values.get_seq_length() if past_key_values is not None else 0 if cache_position is None: cache_position = torch.arange(past_key_values_length, past_key_values_length + seq_length, device=device) embedding_output = self.embeddings( input_ids=input_ids, position_ids=position_ids, token_type_ids=token_type_ids, inputs_embeds=inputs_embeds, past_key_values_length=past_key_values_length, ) attention_mask, encoder_attention_mask = self._create_attention_masks( attention_mask=attention_mask, encoder_attention_mask=encoder_attention_mask, embedding_output=embedding_output, encoder_hidden_states=encoder_hidden_states, cache_position=cache_position, past_key_values=past_key_values, ) encoder_outputs = self.encoder( embedding_output, attention_mask=attention_mask, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, past_key_values=past_key_values, use_cache=use_cache, output_attentions=output_attentions, output_hidden_states=output_hidden_states, cache_position=cache_position, position_ids=position_ids, **kwargs, ) sequence_output = encoder_outputs[0] pooled_output = self.pooler(sequence_output) if self.pooler is not None else None return BaseModelOutputWithPoolingAndCrossAttentions( last_hidden_state=sequence_output, pooler_output=pooled_output, past_key_values=encoder_outputs.past_key_values, hidden_states=encoder_outputs.hidden_states, attentions=encoder_outputs.attentions, cross_attentions=encoder_outputs.cross_attentions, ) # Copied from transformers.models.bert.modeling_bert.BertModel._create_attention_masks def _create_attention_masks( self, attention_mask, encoder_attention_mask, embedding_output, encoder_hidden_states, cache_position, past_key_values, ): if self.config.is_decoder: attention_mask = create_causal_mask( config=self.config, input_embeds=embedding_output, attention_mask=attention_mask, cache_position=cache_position, past_key_values=past_key_values, ) else: attention_mask = create_bidirectional_mask( config=self.config, input_embeds=embedding_output, attention_mask=attention_mask, ) if encoder_attention_mask is not None: encoder_attention_mask = create_bidirectional_mask( config=self.config, input_embeds=embedding_output, attention_mask=encoder_attention_mask, encoder_hidden_states=encoder_hidden_states, ) return attention_mask, encoder_attention_mask @auto_docstring( custom_intro=""" The bare BridgeTower Model transformer outputting BridgeTowerModelOutput object without any specific head on """ ) class BridgeTowerModel(BridgeTowerPreTrainedModel): def __init__(self, config): super().__init__(config) self.config = config vision_config = config.vision_config text_config = config.text_config if config.share_cross_modal_transformer_layers: self.cross_modal_text_transform = nn.Linear(text_config.hidden_size, config.hidden_size) self.cross_modal_image_transform = nn.Linear(vision_config.hidden_size, config.hidden_size) else: self.cross_modal_text_transform = nn.ModuleList( [nn.Linear(text_config.hidden_size, config.hidden_size) for _ in range(config.num_hidden_layers)] ) self.cross_modal_image_transform = nn.ModuleList( [nn.Linear(vision_config.hidden_size, config.hidden_size) for _ in range(config.num_hidden_layers)] ) self.token_type_embeddings = nn.Embedding(2, config.hidden_size) self.vision_model = BridgeTowerVisionModel(vision_config) self.text_model = BridgeTowerTextModel(text_config) if not vision_config.share_layernorm and config.init_layernorm_from_vision_encoder: for ln in self.vision_model.visual.cross_modal_ln_separate: ln.weight.data = self.vision_model.visual.ln_post.weight.data ln.bias.data = self.vision_model.visual.ln_post.bias.data self.cross_modal_image_layers = nn.ModuleList( [BridgeTowerBertCrossLayer(text_config) for _ in range(config.num_hidden_layers)] ) self.cross_modal_text_layers = nn.ModuleList( [BridgeTowerBertCrossLayer(text_config) for _ in range(config.num_hidden_layers)] ) # Class token => Linear => Tanh self.cross_modal_image_pooler = BridgeTowerPooler(config) self.cross_modal_text_pooler = BridgeTowerPooler(config) # Initialize BridgeTower Components self.cross_modal_text_layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) self.cross_modal_image_layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) if config.share_link_tower_layers: self.cross_modal_text_link_tower = BridgeTowerLinkTower(config) self.cross_modal_image_link_tower = BridgeTowerLinkTower(config) else: self.cross_modal_text_link_tower = nn.ModuleList( [BridgeTowerLinkTower(config) for _ in range(config.num_hidden_layers - 1)] ) self.cross_modal_image_link_tower = nn.ModuleList( [BridgeTowerLinkTower(config) for _ in range(config.num_hidden_layers - 1)] ) self.post_init() def get_input_embeddings(self): return self.text_model.get_input_embeddings() def set_input_embeddings(self, value): self.text_model.set_input_embeddings(value) @auto_docstring def forward( self, input_ids: torch.LongTensor | None = None, attention_mask: torch.FloatTensor | None = None, token_type_ids: torch.LongTensor | None = None, pixel_values: torch.FloatTensor | None = None, pixel_mask: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, image_embeds: torch.FloatTensor | None = None, image_token_type_idx: int | None = None, output_attentions: bool | None = None, output_hidden_states: bool | None = None, return_dict: bool | None = None, labels: torch.LongTensor | None = None, interpolate_pos_encoding: bool = False, **kwargs, ) -> tuple[torch.Tensor] | BridgeTowerModelOutput: r""" image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*): Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation. This is useful if you want more control over how to convert `pixel_values` into patch embeddings. image_token_type_idx (`int`, *optional*): - The token type ids for images. output_hidden_states (`bool`, *optional*): If set to `True`, hidden states are returned as a list containing the hidden states of text, image, and cross-modal components respectively. i.e. `(hidden_states_text, hidden_states_image, hidden_states_cross_modal)` where each element is a list of the hidden states of the corresponding modality. `hidden_states_txt/img` are a list of tensors corresponding to unimodal hidden states and `hidden_states_cross_modal` is a list of tuples containing `cross_modal_text_hidden_states` and `cross_modal_image_hidden_states` of each brdige layer. labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*): Labels are currently not supported. Examples: ```python >>> from transformers import BridgeTowerProcessor, BridgeTowerModel >>> from PIL import Image >>> import httpx >>> from io import BytesIO >>> # prepare image and text >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" >>> with httpx.stream("GET", url) as response: ... image = Image.open(BytesIO(response.read())) >>> text = "hello world" >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-base") >>> model = BridgeTowerModel.from_pretrained("BridgeTower/bridgetower-base") >>> inputs = processor(image, text, return_tensors="pt") >>> outputs = model(**inputs) >>> outputs.keys() odict_keys(['text_features', 'image_features', 'pooler_output']) ```""" output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) all_hidden_states_text = () if output_hidden_states else None all_hidden_states_image = () if output_hidden_states else None all_hidden_states_cross = () if output_hidden_states else None all_hidden_states = () if output_hidden_states else None all_self_attentions = () if output_attentions else None if inputs_embeds is not None and input_ids is None: raise NotImplementedError( "BridgeTowerModel does not use `inputs_embeds`. Make sure to pass in `input_ids` instead." ) return_dict = return_dict if return_dict is not None else self.config.use_return_dict image_token_type_idx = image_token_type_idx or 1 input_shape = input_ids.size() text_embeds = self.text_model.embeddings(input_ids=input_ids) if output_hidden_states: all_hidden_states_text += (text_embeds,) if attention_mask is None: attention_mask = torch.ones(input_shape, dtype=torch.long, device=input_ids.device) extend_text_masks = self.text_model.get_extended_attention_mask(attention_mask, input_shape).to( input_ids.device ) # The split_index determines how many layers of the uni-modal encoder are applied before the cross-modal encoder split_index = len(self.text_model.encoder.layer) - self.config.num_hidden_layers + 1 # Run the first 'split_index' layers of the textual encoder for layer in self.text_model.encoder.layer[:split_index]: text_embeds = layer(text_embeds, extend_text_masks)[0] if output_hidden_states: all_hidden_states_text += (text_embeds,) if image_embeds is None: image_embeds = self.vision_model.visual.forward_pre( pixel_values.type(self.vision_model.dtype), interpolate_pos_encoding=interpolate_pos_encoding ) else: # Permute as BridgeTowerResidualAttention has batch_first=True image_embeds = image_embeds.permute(1, 0, 2) if output_hidden_states: all_hidden_states_image += (image_embeds,) # Run the first 'split_index' layers of the visual encoder for block in self.vision_model.visual.transformer.resblocks[:split_index]: image_embeds = block(image_embeds) if output_hidden_states: all_hidden_states_image += (image_embeds,) image_embeds_with_ln = self.vision_model.visual.forward_post(image_embeds.type(self.vision_model.dtype)) # first layer is a special case because we don't have the output from the cross-encoder yet cross_modal_text = self.cross_modal_text_transform(text_embeds) text_token_type_embeddings = self.token_type_embeddings( torch.zeros(1, dtype=torch.long, device=input_ids.device) ).expand_as(cross_modal_text) cross_modal_text = self.cross_modal_text_layernorm(cross_modal_text + text_token_type_embeddings) image_embeds_with_ln = self.cross_modal_image_transform(image_embeds_with_ln) image_token_type_embeddings = self.token_type_embeddings( torch.full((1,), image_token_type_idx, dtype=torch.long, device=input_ids.device) ).expand_as(image_embeds_with_ln) image_embeds_with_ln = image_embeds_with_ln + image_token_type_embeddings cross_modal_image = self.cross_modal_image_layernorm(image_embeds_with_ln) pixel_mask = torch.ones( (cross_modal_image.size(0), cross_modal_image.size(1)), dtype=torch.long, device=input_ids.device, ) extend_image_masks = self.text_model.get_extended_attention_mask(pixel_mask, pixel_mask.size()).to( input_ids.device ) layer_outputs_text = self.cross_modal_text_layers[0]( cross_modal_text, cross_modal_image, attention_mask=extend_text_masks, encoder_attention_mask=extend_image_masks, output_attentions=output_attentions, ) cross_text_features = layer_outputs_text[0] layer_outputs_image = self.cross_modal_image_layers[0]( cross_modal_image, cross_modal_text, attention_mask=extend_image_masks, encoder_attention_mask=extend_text_masks, output_attentions=output_attentions, ) cross_image_features = layer_outputs_image[0] if output_hidden_states: all_hidden_states_cross += ((cross_text_features, cross_image_features),) if output_attentions: all_self_attentions += ((layer_outputs_text[1], layer_outputs_image[1]),) link_layer_index = 0 # Each of the top 6 layers of the visual and textual encoders ([split_index:]) is connected to each layer of # the cross-modal encoder via bridge layers, which brings bottom-up alignment and fusion to the cross-modal encoder. for i in range(split_index, len(self.text_model.encoder.layer)): text_embeds = self.text_model.encoder.layer[i](text_embeds, extend_text_masks)[0] image_embeds = self.vision_model.visual.transformer.resblocks[i](image_embeds).type( self.vision_model.dtype ) image_embeds_with_ln = ( self.cross_modal_image_transform(self.vision_model.visual.forward_post(image_embeds)) + image_token_type_embeddings ) text_link_tower = self.cross_modal_text_link_tower[link_layer_index] image_link_tower = self.cross_modal_image_link_tower[link_layer_index] # Bridge layers for textual and visual encoders cross_text_features_ = text_link_tower( self.cross_modal_text_transform(text_embeds) + text_token_type_embeddings, cross_text_features, extend_text_masks, ) cross_image_features_ = image_link_tower(image_embeds_with_ln, cross_image_features, extend_image_masks) # Cross-modal encoder via bridge layers of textual and visual encoders layer_outputs_text = self.cross_modal_text_layers[link_layer_index + 1]( cross_text_features_, cross_image_features_, attention_mask=extend_text_masks, encoder_attention_mask=extend_image_masks, output_attentions=output_attentions, ) cross_text_features = layer_outputs_text[0] layer_outputs_image = self.cross_modal_image_layers[link_layer_index + 1]( cross_image_features_, cross_text_features_, attention_mask=extend_image_masks, encoder_attention_mask=extend_text_masks, output_attentions=output_attentions, ) cross_image_features = layer_outputs_image[0] link_layer_index += 1 if output_hidden_states: all_hidden_states_text += (text_embeds,) all_hidden_states_image += (image_embeds,) all_hidden_states_cross += ((cross_text_features, cross_image_features),) if output_attentions: all_self_attentions += ((layer_outputs_text[1], layer_outputs_image[1]),) # Concatenate the cls token of the text and image features to get the final represtation text_features, image_features = cross_text_features, cross_image_features cls_features = self.get_cls_features(text_features, image_features) if output_hidden_states: all_hidden_states = (all_hidden_states_text, all_hidden_states_image, all_hidden_states_cross) if not return_dict: return tuple( v for v in [text_features, image_features, cls_features, all_hidden_states, all_self_attentions] if v is not None ) return BridgeTowerModelOutput( text_features=text_features, image_features=image_features, pooler_output=cls_features, hidden_states=all_hidden_states, attentions=all_self_attentions, ) def get_cls_features(self, text_features, image_features): cls_features_text = self.cross_modal_text_pooler(text_features) cls_features_image = self.cross_modal_image_pooler(image_features) return torch.cat([cls_features_text, cls_features_image], dim=-1) # Copied from transformers.models.vilt.modeling_vilt.ViltPredictionHeadTransform with Vilt->BridgeTower class BridgeTowerPredictionHeadTransform(nn.Module): def __init__(self, config): super().__init__() self.dense = nn.Linear(config.hidden_size, config.hidden_size) if isinstance(config.hidden_act, str): self.transform_act_fn = ACT2FN[config.hidden_act] else: self.transform_act_fn = config.hidden_act self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) def forward(self, hidden_states): hidden_states = self.dense(hidden_states) hidden_states = self.transform_act_fn(hidden_states) hidden_states = self.LayerNorm(hidden_states) return hidden_states class BridgeTowerMLMHead(nn.Module): def __init__(self, config, weight=None): super().__init__() self.config = config self.transform = BridgeTowerPredictionHeadTransform(config) self.decoder = nn.Linear(config.hidden_size, config.text_config.vocab_size, bias=False) self.bias = nn.Parameter(torch.zeros(config.text_config.vocab_size)) if weight is not None: self.decoder.weight = weight def forward(self, x): mlm_score = self.transform(x) mlm_score = self.decoder(mlm_score) + self.bias return mlm_score class BridgeTowerITMHead(nn.Module): def __init__(self, hidden_size): super().__init__() self.fc = nn.Linear(hidden_size, 2) def forward(self, x): itm_score = self.fc(x) return itm_score @auto_docstring( custom_intro=""" BridgeTower Model with a language modeling head on top as done during pretraining. """ ) class BridgeTowerForMaskedLM(BridgeTowerPreTrainedModel): _tied_weights_keys = {"mlm_score.decoder.weight": "bridgetower.text_model.embeddings.word_embeddings.weight"} def __init__(self, config): super().__init__(config) self.bridgetower = BridgeTowerModel(config) self.mlm_score = BridgeTowerMLMHead(config) # Initialize weights and apply final processing self.post_init() def get_output_embeddings(self): return self.mlm_score.decoder def set_output_embeddings(self, new_embeddings): self.mlm_score.decoder = new_embeddings @auto_docstring def forward( self, input_ids: torch.LongTensor | None = None, attention_mask: torch.FloatTensor | None = None, token_type_ids: torch.LongTensor | None = None, pixel_values: torch.FloatTensor | None = None, pixel_mask: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, image_embeds: torch.FloatTensor | None = None, output_attentions: bool | None = None, output_hidden_states: bool | None = None, return_dict: bool | None = None, labels: torch.LongTensor | None = None, **kwargs, ) -> MaskedLMOutput | tuple[torch.FloatTensor]: r""" image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*): Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation. This is useful if you want more control over how to convert `pixel_values` into patch embeddings. labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*): Labels for computing the masked language modeling loss. Indices should be in `[-100, 0, ..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are ignored (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]` Examples: ```python >>> from transformers import BridgeTowerProcessor, BridgeTowerForMaskedLM >>> from PIL import Image >>> import httpx >>> from io import BytesIO >>> url = "http://images.cocodataset.org/val2017/000000360943.jpg" >>> with httpx.stream("GET", url) as response: ... image = Image.open(BytesIO(response.read())).convert("RGB") >>> text = "a looking out of the window" >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-base-itm-mlm") >>> model = BridgeTowerForMaskedLM.from_pretrained("BridgeTower/bridgetower-base-itm-mlm") >>> # prepare inputs >>> encoding = processor(image, text, return_tensors="pt") >>> # forward pass >>> outputs = model(**encoding) >>> results = processor.decode(outputs.logits.argmax(dim=-1).squeeze(0).tolist()) >>> print(results) .a cat looking out of the window. ```""" return_dict = return_dict if return_dict is not None else self.config.use_return_dict outputs = self.bridgetower( input_ids, attention_mask=attention_mask, token_type_ids=token_type_ids, pixel_values=pixel_values, pixel_mask=pixel_mask, inputs_embeds=inputs_embeds, image_embeds=image_embeds, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict, ) mlm_logits = self.mlm_score(outputs.text_features if return_dict else outputs[0]) masked_lm_loss = None if labels is not None: loss_fct = CrossEntropyLoss() # -100 index = padding token labels = labels.to(mlm_logits.device) masked_lm_loss = loss_fct(mlm_logits.view(-1, self.config.text_config.vocab_size), labels.view(-1)) if not return_dict: output = tuple(mlm_logits) return ((masked_lm_loss,) + output) if masked_lm_loss is not None else output return MaskedLMOutput( loss=masked_lm_loss, logits=mlm_logits, hidden_states=outputs.hidden_states, attentions=outputs.attentions, ) @auto_docstring( custom_intro=""" BridgeTower Model transformer with a classifier head on top (a linear layer on top of the final hidden state of the [CLS] token) for image-to-text matching. """ ) class BridgeTowerForImageAndTextRetrieval(BridgeTowerPreTrainedModel): def __init__(self, config): super().__init__(config) self.bridgetower = BridgeTowerModel(config) self.itm_score = BridgeTowerITMHead(config.hidden_size * 2) # Initialize weights and apply final processing self.post_init() @auto_docstring def forward( self, input_ids: torch.LongTensor | None = None, attention_mask: torch.FloatTensor | None = None, token_type_ids: torch.LongTensor | None = None, pixel_values: torch.FloatTensor | None = None, pixel_mask: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, image_embeds: torch.FloatTensor | None = None, output_attentions: bool | None = None, output_hidden_states: bool | None = None, return_dict: bool | None = None, labels: torch.LongTensor | None = None, **kwargs, ) -> SequenceClassifierOutput | tuple[torch.FloatTensor]: r""" image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*): Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation. This is useful if you want more control over how to convert `pixel_values` into patch embeddings. labels (`torch.LongTensor` of shape `(batch_size, 1)`, *optional*): Labels for computing the image-text matching loss. 0 means the pairs don't match and 1 means they match. The pairs with 0 will be skipped for calculation. Examples: ```python >>> from transformers import BridgeTowerProcessor, BridgeTowerForImageAndTextRetrieval >>> import httpx >>> from io import BytesIO >>> from PIL import Image >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" >>> with httpx.stream("GET", url) as response: ... image = Image.open(BytesIO(response.read())) >>> texts = ["An image of two cats chilling on a couch", "A football player scoring a goal"] >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-base-itm-mlm") >>> model = BridgeTowerForImageAndTextRetrieval.from_pretrained("BridgeTower/bridgetower-base-itm-mlm") >>> # forward pass >>> scores = dict() >>> for text in texts: ... # prepare inputs ... encoding = processor(image, text, return_tensors="pt") ... outputs = model(**encoding) ... scores[text] = outputs.logits[0, 1].item() ```""" return_dict = return_dict if return_dict is not None else self.config.use_return_dict outputs = self.bridgetower( input_ids, attention_mask=attention_mask, token_type_ids=token_type_ids, pixel_values=pixel_values, pixel_mask=pixel_mask, inputs_embeds=inputs_embeds, image_embeds=image_embeds, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict, ) pooler_output = outputs.pooler_output if return_dict else outputs[2] logits = self.itm_score(pooler_output) itm_loss = None if labels is not None: loss_fct = CrossEntropyLoss() labels = labels.to(logits.device) itm_loss = loss_fct(logits, labels) if not return_dict: output = tuple(logits) return ((itm_loss,) + output) if itm_loss is not None else output return SequenceClassifierOutput( loss=itm_loss, logits=logits, hidden_states=outputs.hidden_states, attentions=outputs.attentions, ) class BridgeTowerContrastiveHead(nn.Module): def __init__(self, hidden_size, embed_size): super().__init__() self.fc = nn.Linear(hidden_size, embed_size) def forward(self, x): x = self.fc(x) return x @auto_docstring( custom_intro=""" BridgeTower Model with a image-text contrastive head on top computing image-text contrastive loss. """ ) class BridgeTowerForContrastiveLearning(BridgeTowerPreTrainedModel): def __init__(self, config): super().__init__(config) self.bridgetower = BridgeTowerModel(config) self.itc_text_head = BridgeTowerContrastiveHead(config.hidden_size, config.contrastive_hidden_size) self.itc_image_head = BridgeTowerContrastiveHead(config.hidden_size, config.contrastive_hidden_size) self.itc_cross_modal_head = BridgeTowerContrastiveHead(config.hidden_size * 2, config.contrastive_hidden_size) self.logit_scale = nn.Parameter(torch.tensor(self.config.logit_scale_init_value)) # Initialize weights and apply final processing self.post_init() @auto_docstring def forward( self, input_ids: torch.LongTensor | None = None, attention_mask: torch.FloatTensor | None = None, token_type_ids: torch.LongTensor | None = None, pixel_values: torch.FloatTensor | None = None, pixel_mask: torch.LongTensor | None = None, inputs_embeds: torch.FloatTensor | None = None, image_embeds: torch.FloatTensor | None = None, output_attentions: bool | None = None, output_hidden_states: bool | None = True, return_dict: bool | None = None, return_loss: bool | None = None, **kwargs, ) -> BridgeTowerContrastiveOutput | tuple[torch.FloatTensor]: r""" image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*): Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation. This is useful if you want more control over how to convert `pixel_values` into patch embeddings. return_loss (`bool`, *optional*): Whether or not to return the contrastive loss. Examples: ```python >>> from transformers import BridgeTowerProcessor, BridgeTowerForContrastiveLearning >>> import httpx >>> from io import BytesIO >>> from PIL import Image >>> import torch >>> image_urls = [ ... "https://farm4.staticflickr.com/3395/3428278415_81c3e27f15_z.jpg", ... "http://images.cocodataset.org/val2017/000000039769.jpg", ... ] >>> texts = ["two dogs in a car", "two cats sleeping on a couch"] >>> with httpx.stream("GET", urls[0]) as response: ... image1 = Image.open(BytesIO(response.read())) >>> with httpx.stream("GET", urls[1]) as response: ... image2 = Image.open(BytesIO(response.read())) >>> images = [image1, image2] >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-large-itm-mlm-itc") >>> model = BridgeTowerForContrastiveLearning.from_pretrained("BridgeTower/bridgetower-large-itm-mlm-itc") >>> inputs = processor(images, texts, padding=True, return_tensors="pt") >>> loss = model(**inputs, return_loss=True).loss >>> inputs = processor(images, texts[::-1], padding=True, return_tensors="pt") >>> loss_swapped = model(**inputs, return_loss=True).loss >>> print("Loss", round(loss.item(), 4)) Loss 0.0019 >>> print("Loss with swapped images", round(loss_swapped.item(), 4)) Loss with swapped images 2.126 ```""" return_dict = return_dict if return_dict is not None else self.config.use_return_dict outputs = self.bridgetower( input_ids, attention_mask=attention_mask, token_type_ids=token_type_ids, pixel_values=pixel_values, pixel_mask=pixel_mask, inputs_embeds=inputs_embeds, image_embeds=image_embeds, output_attentions=output_attentions, output_hidden_states=True, return_dict=return_dict, ) pooler_output = outputs.pooler_output if return_dict else outputs[2] hidden_states_txt, hidden_states_img, hidden_states_cross_modal = ( outputs.hidden_states if return_dict else outputs[3] ) text_embeds = hidden_states_txt[-1] image_embeds = hidden_states_img[-1] image_embeds_with_ln = self.bridgetower.vision_model.visual.forward_post(image_embeds) image_token_type_embeddings = self.bridgetower.token_type_embeddings( torch.full((1,), 1, dtype=torch.long, device=self.bridgetower.token_type_embeddings.weight.device) ).expand_as(image_embeds_with_ln) image_embeds = self.bridgetower.cross_modal_image_transform(image_embeds_with_ln) + image_token_type_embeddings # normalized features text_embeds = nn.functional.normalize(self.itc_text_head(text_embeds[:, 0, :]), dim=-1, p=2) image_embeds = nn.functional.normalize(self.itc_image_head(image_embeds[:, 0, :]), dim=-1, p=2).to( device=text_embeds.device ) cross_embeds = nn.functional.normalize(self.itc_cross_modal_head(pooler_output), dim=-1, p=2).to( device=text_embeds.device ) logits = torch.stack([text_embeds, image_embeds, cross_embeds], dim=-2) logit_scale = self.logit_scale.exp().to(device=text_embeds.device) logits_text_to_image = torch.matmul(text_embeds, image_embeds.t()) * logit_scale logits_text_to_cross = torch.matmul(text_embeds, cross_embeds.t()) * logit_scale logits_image_to_cross = torch.matmul(image_embeds, cross_embeds.t()) * logit_scale itc_loss = None if return_loss: labels = torch.arange(len(logits), device=logits.device) text_to_image_loss = nn.functional.cross_entropy(logits_text_to_image, labels) text_to_cross_loss = nn.functional.cross_entropy(logits_text_to_cross, labels) image_to_cross_loss = nn.functional.cross_entropy(logits_image_to_cross, labels) itc_loss = (text_to_image_loss + text_to_cross_loss + image_to_cross_loss) / 3.0 if not return_dict: output = (logits, text_embeds, image_embeds, cross_embeds) + outputs[3:] return ((itc_loss,) + output) if itc_loss is not None else output return BridgeTowerContrastiveOutput( loss=itc_loss, logits=logits, text_embeds=text_embeds, image_embeds=image_embeds, cross_embeds=cross_embeds, hidden_states=outputs.hidden_states, attentions=outputs.attentions, ) __all__ = [ "BridgeTowerForContrastiveLearning", "BridgeTowerForImageAndTextRetrieval", "BridgeTowerForMaskedLM", "BridgeTowerModel", "BridgeTowerPreTrainedModel", ]