diff --git "a/docs/transformers/src/transformers/models/blip_2/modeling_blip_2.py" "b/docs/transformers/src/transformers/models/blip_2/modeling_blip_2.py" new file mode 100644--- /dev/null +++ "b/docs/transformers/src/transformers/models/blip_2/modeling_blip_2.py" @@ -0,0 +1,2643 @@ +# coding=utf-8 +# Copyright 2023 The Salesforce Authors and The HuggingFace 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 BLIP-2 model.""" + +import math +from dataclasses import dataclass +from typing import Any, Optional, Tuple, Union + +import torch +import torch.utils.checkpoint +from torch import nn +from torch.nn import CrossEntropyLoss + +from ...activations import ACT2FN +from ...generation import GenerationMixin +from ...modeling_outputs import ( + BaseModelOutput, + BaseModelOutputWithPastAndCrossAttentions, + BaseModelOutputWithPooling, + BaseModelOutputWithPoolingAndCrossAttentions, +) +from ...modeling_utils import PreTrainedModel +from ...pytorch_utils import apply_chunking_to_forward, find_pruneable_heads_and_indices, prune_linear_layer +from ...utils import ( + ModelOutput, + add_start_docstrings, + add_start_docstrings_to_model_forward, + logging, + replace_return_docstrings, + torch_int, +) +from ..auto import AutoModelForCausalLM, AutoModelForSeq2SeqLM +from .configuration_blip_2 import Blip2Config, Blip2QFormerConfig, Blip2VisionConfig + + +logger = logging.get_logger(__name__) + +_CHECKPOINT_FOR_DOC = "Salesforce/blip2-opt-2.7b" + + +@dataclass +class Blip2ForConditionalGenerationModelOutput(ModelOutput): + """ + Class defining the outputs of [`Blip2ForConditionalGeneration`]. + + Args: + loss (`torch.FloatTensor`, *optional*, returned when `labels` is provided, `torch.FloatTensor` of shape `(1,)`): + Language modeling loss from the language model. + logits (`torch.FloatTensor` of shape `(batch_size, sequence_length, config.vocab_size)`): + Prediction scores of the language modeling head of the language model. + vision_outputs (`BaseModelOutputWithPooling`): + Outputs of the vision encoder. + qformer_outputs (`BaseModelOutputWithPoolingAndCrossAttentions`): + Outputs of the Q-Former (Querying Transformer). + language_model_outputs (`CausalLMOutputWithPast` or `Seq2SeqLMOutput`): + Outputs of the language model. + """ + + loss: Optional[Tuple[torch.FloatTensor]] = None + logits: Optional[Tuple[torch.FloatTensor]] = None + vision_outputs: Optional[torch.FloatTensor] = None + qformer_outputs: Optional[Tuple[torch.FloatTensor]] = None + language_model_outputs: Optional[Tuple[torch.FloatTensor]] = None + + def to_tuple(self) -> Tuple[Any]: + return tuple( + self[k] + if k not in ["vision_outputs", "qformer_outputs", "language_model_outputs"] + else getattr(self, k).to_tuple() + for k in self.keys() + ) + + +@dataclass +class Blip2ImageTextMatchingModelOutput(ModelOutput): + """ + Args: + loss (`torch.FloatTensor` of shape `(1,)`, *optional*, returned when `return_loss` is `True`): + Contrastive loss for image-text similarity. + logits_per_image (`torch.FloatTensor` of shape `(image_batch_size, text_batch_size)`): + The scaled dot product scores between `image_embeds` and `text_embeds`. This represents the image-text + similarity scores. + logits_per_text (`torch.FloatTensor` of shape `(text_batch_size, image_batch_size)`): + The scaled dot product scores between `text_embeds` and `image_embeds`. This represents the text-image + similarity scores. + text_embeds (`torch.FloatTensor` of shape `(batch_size, output_dim`): + The text embeddings obtained by applying the projection layer to the pooled output. + image_embeds (`torch.FloatTensor` of shape `(batch_size, output_dim`): + The image embeddings obtained by applying the projection layer to the pooled output. + text_model_output (`BaseModelOutputWithPooling`): + The output of the [`Blip2QFormerModel`]. + vision_model_output (`BaseModelOutputWithPooling`): + The output of the [`Blip2VisionModel`]. + """ + + loss: Optional[torch.FloatTensor] = None + logits_per_image: Optional[torch.FloatTensor] = None + logits_per_text: Optional[torch.FloatTensor] = None + text_embeds: Optional[torch.FloatTensor] = None + image_embeds: Optional[torch.FloatTensor] = None + text_model_output: BaseModelOutputWithPooling = None + vision_model_output: BaseModelOutputWithPooling = None + + def to_tuple(self) -> Tuple[Any]: + return tuple( + self[k] if k not in ["text_model_output", "vision_model_output"] else getattr(self, k).to_tuple() + for k in self.keys() + ) + + +@dataclass +# Copied from transformers.models.clip.modeling_clip.CLIPTextModelOutput with CLIP->Blip2 +class Blip2TextModelOutput(ModelOutput): + """ + Base class for text model's outputs that also contains a pooling of the last hidden states. + + Args: + text_embeds (`torch.FloatTensor` of shape `(batch_size, output_dim)` *optional* returned when model is initialized with `with_projection=True`): + The text embeddings obtained by applying the projection layer to the pooler_output. + last_hidden_state (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`): + Sequence of hidden-states at the output of the last layer of the model. + hidden_states (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`): + Tuple of `torch.FloatTensor` (one for the output of the embeddings, if the model has an embedding layer, + + one for the output of each layer) of shape `(batch_size, sequence_length, hidden_size)`. + + Hidden-states of the model at the output of each layer plus the optional initial embedding outputs. + 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)`. + + Attentions weights after the attention softmax, used to compute the weighted average in the self-attention + heads. + """ + + text_embeds: Optional[torch.FloatTensor] = None + last_hidden_state: Optional[torch.FloatTensor] = None + hidden_states: Optional[Tuple[torch.FloatTensor, ...]] = None + attentions: Optional[Tuple[torch.FloatTensor, ...]] = None + + +@dataclass +# Copied from transformers.models.clip.modeling_clip.CLIPVisionModelOutput with CLIP->Blip2 +class Blip2VisionModelOutput(ModelOutput): + """ + Base class for vision model's outputs that also contains image embeddings of the pooling of the last hidden states. + + Args: + image_embeds (`torch.FloatTensor` of shape `(batch_size, output_dim)` *optional* returned when model is initialized with `with_projection=True`): + The image embeddings obtained by applying the projection layer to the pooler_output. + last_hidden_state (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`): + Sequence of hidden-states at the output of the last layer of the model. + hidden_states (`tuple(torch.FloatTensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`): + Tuple of `torch.FloatTensor` (one for the output of the embeddings, if the model has an embedding layer, + + one for the output of each layer) of shape `(batch_size, sequence_length, hidden_size)`. + + Hidden-states of the model at the output of each layer plus the optional initial embedding outputs. + 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)`. + + Attentions weights after the attention softmax, used to compute the weighted average in the self-attention + heads. + """ + + image_embeds: Optional[torch.FloatTensor] = None + last_hidden_state: Optional[torch.FloatTensor] = None + hidden_states: Optional[Tuple[torch.FloatTensor, ...]] = None + attentions: Optional[Tuple[torch.FloatTensor, ...]] = None + + +# Copied from transformers.models.blip.modeling_blip.BlipVisionEmbeddings with Blip->Blip2 +class Blip2VisionEmbeddings(nn.Module): + def __init__(self, config: Blip2VisionConfig): + 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(1, 1, self.embed_dim)) + + self.patch_embedding = nn.Conv2d( + in_channels=3, out_channels=self.embed_dim, kernel_size=self.patch_size, stride=self.patch_size + ) + + self.num_patches = (self.image_size // self.patch_size) ** 2 + self.num_positions = self.num_patches + 1 + + self.position_embedding = nn.Parameter(torch.randn(1, self.num_positions, self.embed_dim)) + + 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 + num_positions = self.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 + + class_pos_embed = self.position_embedding[:, :1] + patch_pos_embed = self.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: bool = False) -> torch.Tensor: + batch_size, _, height, width = pixel_values.shape + 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).to(target_dtype) + embeddings = torch.cat([class_embeds, patch_embeds], dim=1) + if interpolate_pos_encoding: + position_embedding = self.interpolate_pos_encoding(embeddings, height, width) + else: + position_embedding = self.position_embedding + embeddings = embeddings + position_embedding[:, : embeddings.size(1), :].to(target_dtype) + return embeddings + + +class Blip2Attention(nn.Module): + """Multi-headed attention from 'Attention Is All You Need' paper""" + + def __init__(self, config): + super().__init__() + self.config = config + self.embed_dim = config.hidden_size + self.num_heads = config.num_attention_heads + self.head_dim = self.embed_dim // self.num_heads + if self.head_dim * self.num_heads != self.embed_dim: + raise ValueError( + f"embed_dim must be divisible by num_heads (got `embed_dim`: {self.embed_dim} and `num_heads`:" + f" {self.num_heads})." + ) + self.scale = self.head_dim**-0.5 + self.dropout = nn.Dropout(config.attention_dropout) + + # small tweak here compared to CLIP, no bias here + self.qkv = nn.Linear(self.embed_dim, 3 * self.embed_dim, bias=False) + + if config.qkv_bias: + q_bias = nn.Parameter(torch.zeros(self.embed_dim)) + v_bias = nn.Parameter(torch.zeros(self.embed_dim)) + else: + q_bias = None + v_bias = None + + if q_bias is not None: + qkv_bias = torch.cat((q_bias, torch.zeros_like(v_bias, requires_grad=False), v_bias)) + self.qkv.bias = nn.Parameter(qkv_bias) + + self.projection = nn.Linear(self.embed_dim, self.embed_dim) + + def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int): + return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous() + + def forward( + self, + hidden_states: torch.Tensor, + head_mask: Optional[torch.Tensor] = None, + output_attentions: Optional[bool] = False, + ) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]: + """Input shape: Batch x Time x Channel""" + + bsz, tgt_len, embed_dim = hidden_states.size() + + mixed_qkv = self.qkv(hidden_states) + + mixed_qkv = mixed_qkv.reshape(bsz, tgt_len, 3, self.num_heads, embed_dim // self.num_heads).permute( + 2, 0, 3, 1, 4 + ) + query_states, key_states, value_states = mixed_qkv[0], mixed_qkv[1], mixed_qkv[2] + + # Take the dot product between "query" and "key" to get the raw attention scores. + attention_scores = torch.matmul(query_states, key_states.transpose(-1, -2)) + + attention_scores = attention_scores * self.scale + + # Normalize the attention scores to probabilities. + attention_probs = nn.functional.softmax(attention_scores, dim=-1) + + # This is actually dropping out entire tokens to attend to, which might + # seem a bit unusual, but is taken from the original Transformer paper. + attention_probs = self.dropout(attention_probs) + + # Mask heads if we want to + if head_mask is not None: + attention_probs = attention_probs * head_mask + + context_layer = torch.matmul(attention_probs, value_states).permute(0, 2, 1, 3) + + new_context_layer_shape = context_layer.size()[:-2] + (self.embed_dim,) + context_layer = context_layer.reshape(new_context_layer_shape) + + output = self.projection(context_layer) + + outputs = (output, attention_probs) if output_attentions else (output, None) + + return outputs + + +# Copied from transformers.models.blip.modeling_blip.BlipMLP +class Blip2MLP(nn.Module): + def __init__(self, config): + super().__init__() + self.config = config + self.activation_fn = ACT2FN[config.hidden_act] + self.fc1 = nn.Linear(config.hidden_size, config.intermediate_size) + self.fc2 = nn.Linear(config.intermediate_size, config.hidden_size) + + def forward(self, hidden_states: torch.Tensor) -> torch.Tensor: + hidden_states = self.fc1(hidden_states) + hidden_states = self.activation_fn(hidden_states) + hidden_states = self.fc2(hidden_states) + return hidden_states + + +# Copied from transformers.models.blip.modeling_blip.BlipEncoderLayer with Blip->Blip2 +class Blip2EncoderLayer(nn.Module): + def __init__(self, config: Blip2Config): + super().__init__() + self.embed_dim = config.hidden_size + self.self_attn = Blip2Attention(config) + self.layer_norm1 = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_eps) + self.mlp = Blip2MLP(config) + self.layer_norm2 = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_eps) + + def forward( + self, + hidden_states: torch.Tensor, + attention_mask: torch.Tensor, + output_attentions: Optional[bool] = False, + ) -> Tuple[torch.FloatTensor]: + """ + Args: + hidden_states (`torch.FloatTensor`): input to the layer of shape `(batch, seq_len, embed_dim)` + attention_mask (`torch.FloatTensor`): attention mask of size + `(batch, 1, tgt_len, src_len)` where padding elements are indicated by very large negative values. + `(config.encoder_attention_heads,)`. + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under + returned tensors for more detail. + """ + residual = hidden_states + + hidden_states = self.layer_norm1(hidden_states) + hidden_states, attn_weights = self.self_attn( + hidden_states=hidden_states, + head_mask=attention_mask, + output_attentions=output_attentions, + ) + hidden_states = hidden_states + residual + residual = hidden_states + hidden_states = self.layer_norm2(hidden_states) + hidden_states = self.mlp(hidden_states) + + hidden_states = hidden_states + residual + + outputs = (hidden_states,) + + if output_attentions: + outputs += (attn_weights,) + + return outputs + + +class Blip2PreTrainedModel(PreTrainedModel): + """ + An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained + models. + """ + + config_class = Blip2Config + base_model_prefix = "blip" + supports_gradient_checkpointing = True + + _no_split_modules = [ + "Blip2Attention", + "Blip2QFormerMultiHeadAttention", + "Blip2TextEmbeddings", + "T5Block", + "OPTDecoderLayer", + ] + _skip_keys_device_placement = "past_key_values" + + def _init_weights(self, module): + """Initialize the weights""" + factor = self.config.initializer_range + + if isinstance(module, (nn.Linear, nn.Conv2d)): + module.weight.data.normal_(mean=0.0, std=factor) + if module.bias is not None: + module.bias.data.zero_() + elif isinstance(module, nn.Embedding): + module.weight.data.normal_(mean=0.0, std=factor) + elif isinstance(module, nn.LayerNorm): + module.bias.data.zero_() + module.weight.data.fill_(1.0) + elif isinstance(module, Blip2VisionEmbeddings): + nn.init.trunc_normal_(module.position_embedding, mean=0.0, std=factor) + nn.init.trunc_normal_(module.class_embedding, mean=0.0, std=factor) + elif isinstance( + module, + ( + Blip2Model, + Blip2TextModelWithProjection, + Blip2VisionModelWithProjection, + Blip2ForConditionalGeneration, + Blip2ForImageTextRetrieval, + ), + ): + module.query_tokens.data.zero_() + + +BLIP_2_START_DOCSTRING = r""" + This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the + library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads + etc.) + + This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass. + Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage + and behavior. + + Parameters: + config ([`Blip2Config`]): Model configuration class with all the parameters of the model. + Initializing with a config file does not load the weights associated with the model, only the + configuration. Check out the [`~PreTrainedModel.from_pretrained`] method to load the model weights. +""" + +BLIP_2_QFORMER_START_DOCSTRING = r""" + This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the + library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads + etc.) + + This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass. + Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage + and behavior. + + Parameters: + config ([`Blip2QFormerConfig`]): Model configuration class with all the parameters of the model. + Initializing with a config file does not load the weights associated with the model, only the + configuration. Check out the [`~PreTrainedModel.from_pretrained`] method to load the model weights. +""" + +BLIP_2_VISION_INPUTS_DOCSTRING = r""" + Args: + pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`): + Pixel values. Pixel values can be obtained using [`Blip2Processor`]. See [`Blip2Processor.__call__`] for + details. + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. + interpolate_pos_encoding (`bool`, *optional*, defaults to `False`): + Whether to interpolate the pre-trained position encodings. +""" + +BLIP_2_TEXT_INPUTS_DOCSTRING = r""" + Args: + input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`): + Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you provide + it. Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for details. [What are input IDs?](../glossary#input-ids) + attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + [What are attention masks?](../glossary#attention-mask) + decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*): + Indices of decoder input sequence tokens in the vocabulary. + + Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for details. + + [What are decoder input IDs?](../glossary#decoder-input-ids) + + T5 uses the `pad_token_id` as the starting token for `decoder_input_ids` generation. If `past_key_values` + is used, optionally only the last `decoder_input_ids` have to be input (see `past_key_values`). + + To know more on how to prepare `decoder_input_ids` for pretraining take a look at [T5 + Training](./t5#training). + decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*): + Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also + be used by default. + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. +""" + +BLIP_2_TEXT_WITH_PROJECTION_INPUTS_DOCSTRING = r""" + Args: + input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`): + Indices of input sequence tokens in the vocabulary. Padding will be ignored by default should you provide + it. Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for details. [What are input IDs?](../glossary#input-ids) + attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + [What are attention masks?](../glossary#attention-mask) + position_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*): + Indices of positions of each input sequence tokens in the position embeddings. Selected in the range `[0, + config.max_position_embeddings - 1]`. + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. +""" + +BLIP_2_INPUTS_DOCSTRING = r""" + Args: + pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`): + Pixel values. Pixel values can be obtained using [`Blip2Processor`]. See [`Blip2Processor.__call__`] for + details. + + input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*): + Indices of input sequence tokens in the vocabulary of the language model. Input tokens can optionally be + provided to serve as text prompt, which the language model can continue. + + Indices can be obtained using [`Blip2Processor`]. See [`Blip2Processor.__call__`] for details. + + [What are input IDs?](../glossary#input-ids) + attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + + [What are attention masks?](../glossary#attention-mask) + + decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*): + Indices of decoder input sequence tokens in the vocabulary of the language model. Only relevant in case an + encoder-decoder language model (like T5) is used. + + Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for details. [What are decoder input IDs?](../glossary#decoder-input-ids) + + decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*): + Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also + be used by default. + + Only relevant in case an encoder-decoder language model (like T5) is used. + + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. + interpolate_pos_encoding (`bool`, *optional*, defaults to `False`): + Whether to interpolate the pre-trained position encodings. + use_cache (`bool`, *optional*): + If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see + `past_key_values`). +""" + +BLIP2_IMAGE_TEXT_RETRIEVAL_INPUTS_DOCSTRING = r""" + Args: + pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`): + Pixel values. Pixel values can be obtained using [`Blip2Processor`]. See [`Blip2Processor.__call__`] for + details. + + input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*): + Indices of input sequence tokens in the vocabulary of the language model. Input tokens can optionally be + provided to serve as text prompt, which the language model can continue. + + Indices can be obtained using [`Blip2Processor`]. See [`Blip2Processor.__call__`] for details. + + [What are input IDs?](../glossary#input-ids) + + attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + + [What are attention masks?](../glossary#attention-mask) + + use_image_text_matching_head (`bool`, *optional*): + Whether to return the Image-Text Matching or Contrastive scores. + + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. +""" + + +BLIP2_QFORMER_INPUTS_DOCSTRING = r""" + Args: + query_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`): + Hidden states to be used in the attention computation. If cross-attention, + will be used for the query (i.e., key and value will use the encoder_hidden_states). + + query_length (`int`, *optional*): + Length of the query, usually based on the number of query tokens. + If no value is provided, query_length will be inferred by the query_embeds. + + attention_mask (`torch.FloatTensor`, *optional*): + Attention mask of size `(batch, sequence_length)` where padding elements + are indicated by 0. + + head_mask (`torch.FloatTensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*): + Mask to nullify selected heads of the self-attention modules. Mask values selected in `[0, 1]`: + + - 1 indicates the head is **not masked**, + - 0 indicates the head is **masked**. + + encoder_hidden_states (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, `optional`): + Sequence of hidden-states at the output of the last layer of the encoder. Used in the cross-attention if + the model is configured as a decoder. + + encoder_attention_mask (`torch.FloatTensor` of shape `(batch_size, sequence_length)`, `optional`): + Mask to avoid performing attention on the padding token indices of the encoder input. This mask is used in + the cross-attention if the model is configured as a decoder. Mask values selected in `[0, 1]`: + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + + past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of: + shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`): Contains precomputed key and + value hidden states of the attention blocks. Can be used to speed up decoding. If `past_key_values` are + used, the user can optionally input only the last `decoder_input_ids` (those that don't have their past key + value states given to this model) of shape `(batch_size, 1)` instead of all `decoder_input_ids` of shape + `(batch_size, sequence_length)`. + + use_cache (`bool`, `optional`): + If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see + `past_key_values`). + + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. +""" + + +# Copied from transformers.models.blip.modeling_blip.BlipEncoder with Blip->Blip2 +class Blip2Encoder(nn.Module): + """ + Transformer encoder consisting of `config.num_hidden_layers` self attention layers. Each layer is a + [`Blip2EncoderLayer`]. + + Args: + config (`Blip2Config`): + The corresponding vision configuration for the `Blip2Encoder`. + """ + + def __init__(self, config: Blip2Config): + super().__init__() + self.config = config + self.layers = nn.ModuleList([Blip2EncoderLayer(config) for _ in range(config.num_hidden_layers)]) + self.gradient_checkpointing = False + + def forward( + self, + inputs_embeds, + attention_mask: Optional[torch.Tensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple, BaseModelOutput]: + r""" + Args: + inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`): + Embedded representation of the inputs. Should be float, not int tokens. + attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + + [What are attention masks?](../glossary#attention-mask) + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under + returned tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors + for more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. + """ + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + encoder_states = () if output_hidden_states else None + all_attentions = () if output_attentions else None + + hidden_states = inputs_embeds + for idx, encoder_layer in enumerate(self.layers): + if output_hidden_states: + encoder_states = encoder_states + (hidden_states,) + if self.gradient_checkpointing and self.training: + layer_outputs = self._gradient_checkpointing_func( + encoder_layer.__call__, + hidden_states, + attention_mask, + output_attentions, + ) + else: + layer_outputs = encoder_layer( + hidden_states, + attention_mask, + output_attentions=output_attentions, + ) + + hidden_states = layer_outputs[0] + + if output_attentions: + all_attentions = all_attentions + (layer_outputs[1],) + + if output_hidden_states: + encoder_states = encoder_states + (hidden_states,) + + if not return_dict: + return tuple(v for v in [hidden_states, encoder_states, all_attentions] if v is not None) + return BaseModelOutput( + last_hidden_state=hidden_states, hidden_states=encoder_states, attentions=all_attentions + ) + + +# Copied from transformers.models.blip.modeling_blip.BlipVisionModel with Blip->Blip2, BLIP->BLIP_2 +class Blip2VisionModel(Blip2PreTrainedModel): + main_input_name = "pixel_values" + config_class = Blip2VisionConfig + + def __init__(self, config: Blip2VisionConfig): + super().__init__(config) + self.config = config + embed_dim = config.hidden_size + + self.embeddings = Blip2VisionEmbeddings(config) + self.encoder = Blip2Encoder(config) + self.post_layernorm = nn.LayerNorm(embed_dim, eps=config.layer_norm_eps) + + self.post_init() + + @add_start_docstrings_to_model_forward(BLIP_2_VISION_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=BaseModelOutputWithPooling, config_class=Blip2VisionConfig) + def forward( + self, + pixel_values: Optional[torch.FloatTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + interpolate_pos_encoding: bool = False, + ) -> Union[Tuple, BaseModelOutputWithPooling]: + r""" + Returns: + + """ + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + if pixel_values is None: + raise ValueError("You have to specify pixel_values") + + hidden_states = self.embeddings(pixel_values, interpolate_pos_encoding=interpolate_pos_encoding) + + encoder_outputs = self.encoder( + inputs_embeds=hidden_states, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + last_hidden_state = encoder_outputs[0] + last_hidden_state = self.post_layernorm(last_hidden_state) + + pooled_output = last_hidden_state[:, 0, :] + pooled_output = self.post_layernorm(pooled_output) + + if not return_dict: + return (last_hidden_state, pooled_output) + encoder_outputs[1:] + + return BaseModelOutputWithPooling( + last_hidden_state=last_hidden_state, + pooler_output=pooled_output, + hidden_states=encoder_outputs.hidden_states, + attentions=encoder_outputs.attentions, + ) + + def get_input_embeddings(self): + return self.embeddings + + +class Blip2QFormerMultiHeadAttention(nn.Module): + def __init__(self, config, is_cross_attention=False): + super().__init__() + self.config = config + if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"): + raise ValueError( + "The hidden size (%d) is not a multiple of the number of attention heads (%d)" + % (config.hidden_size, config.num_attention_heads) + ) + + 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.query = nn.Linear(config.hidden_size, self.all_head_size) + if is_cross_attention: + self.key = nn.Linear(config.encoder_hidden_size, self.all_head_size) + self.value = nn.Linear(config.encoder_hidden_size, self.all_head_size) + else: + 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.position_embedding_type = getattr(config, "position_embedding_type", "absolute") + if self.position_embedding_type == "relative_key" or self.position_embedding_type == "relative_key_query": + self.max_position_embeddings = config.max_position_embeddings + self.distance_embedding = nn.Embedding(2 * config.max_position_embeddings - 1, self.attention_head_size) + self.save_attention = False + + def save_attn_gradients(self, attn_gradients): + self.attn_gradients = attn_gradients + + def get_attn_gradients(self): + return self.attn_gradients + + def save_attention_map(self, attention_map): + self.attention_map = attention_map + + def get_attention_map(self): + return self.attention_map + + def transpose_for_scores(self, x): + new_x_shape = x.size()[:-1] + (self.num_attention_heads, self.attention_head_size) + x = x.view(*new_x_shape) + return x.permute(0, 2, 1, 3) + + def forward( + self, + hidden_states, + attention_mask=None, + head_mask=None, + encoder_hidden_states=None, + encoder_attention_mask=None, + past_key_value=None, + output_attentions=False, + ): + # If this is instantiated as a cross-attention module, the keys + # and values come from an encoder; the attention mask needs to be + # such that the encoder's padding tokens are not attended to. + is_cross_attention = encoder_hidden_states is not None + + if is_cross_attention: + key_layer = self.transpose_for_scores(self.key(encoder_hidden_states)) + value_layer = self.transpose_for_scores(self.value(encoder_hidden_states)) + attention_mask = encoder_attention_mask + elif past_key_value is not None: + key_layer = self.transpose_for_scores(self.key(hidden_states)) + value_layer = self.transpose_for_scores(self.value(hidden_states)) + key_layer = torch.cat([past_key_value[0], key_layer], dim=2) + value_layer = torch.cat([past_key_value[1], value_layer], dim=2) + else: + key_layer = self.transpose_for_scores(self.key(hidden_states)) + value_layer = self.transpose_for_scores(self.value(hidden_states)) + + mixed_query_layer = self.query(hidden_states) + + query_layer = self.transpose_for_scores(mixed_query_layer) + + past_key_value = (key_layer, value_layer) + + # Take the dot product between "query" and "key" to get the raw attention scores. + attention_scores = torch.matmul(query_layer, key_layer.transpose(-1, -2)) + + if self.position_embedding_type == "relative_key" or self.position_embedding_type == "relative_key_query": + seq_length = hidden_states.size()[1] + position_ids_l = torch.arange(seq_length, dtype=torch.long, device=hidden_states.device).view(-1, 1) + position_ids_r = torch.arange(seq_length, dtype=torch.long, device=hidden_states.device).view(1, -1) + distance = position_ids_l - position_ids_r + positional_embedding = self.distance_embedding(distance + self.max_position_embeddings - 1) + positional_embedding = positional_embedding.to(dtype=query_layer.dtype) # fp16 compatibility + + if self.position_embedding_type == "relative_key": + relative_position_scores = torch.einsum("bhld,lrd->bhlr", query_layer, positional_embedding) + attention_scores = attention_scores + relative_position_scores + elif self.position_embedding_type == "relative_key_query": + relative_position_scores_query = torch.einsum("bhld,lrd->bhlr", query_layer, positional_embedding) + relative_position_scores_key = torch.einsum("bhrd,lrd->bhlr", key_layer, positional_embedding) + attention_scores = attention_scores + relative_position_scores_query + relative_position_scores_key + + attention_scores = attention_scores / math.sqrt(self.attention_head_size) + + if attention_mask is not None: + # Apply the attention mask is (precomputed for all layers in BertModel forward() function) + attention_scores = attention_scores + attention_mask + + # Normalize the attention scores to probabilities. + attention_probs = nn.Softmax(dim=-1)(attention_scores) + + if is_cross_attention and self.save_attention: + self.save_attention_map(attention_probs) + attention_probs.register_hook(self.save_attn_gradients) + + # This is actually dropping out entire tokens to attend to, which might + # seem a bit unusual, but is taken from the original Transformer paper. + attention_probs_dropped = self.dropout(attention_probs) + + # Mask heads if we want to + if head_mask is not None: + attention_probs_dropped = attention_probs_dropped * head_mask + + context_layer = torch.matmul(attention_probs_dropped, value_layer) + + context_layer = context_layer.permute(0, 2, 1, 3).contiguous() + new_context_layer_shape = context_layer.size()[:-2] + (self.all_head_size,) + context_layer = context_layer.view(*new_context_layer_shape) + + outputs = (context_layer, attention_probs) if output_attentions else (context_layer,) + + outputs = outputs + (past_key_value,) + return outputs + + +# Copied from transformers.models.bert.modeling_bert.BertSelfOutput with Bert->Blip2QFormer +class Blip2QFormerSelfOutput(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 + + +class Blip2QFormerAttention(nn.Module): + def __init__(self, config, is_cross_attention=False): + super().__init__() + self.attention = Blip2QFormerMultiHeadAttention(config, is_cross_attention) + self.output = Blip2QFormerSelfOutput(config) + self.pruned_heads = set() + + def prune_heads(self, heads): + if len(heads) == 0: + return + heads, index = find_pruneable_heads_and_indices( + heads, self.attention.num_attention_heads, self.attention.attention_head_size, self.pruned_heads + ) + + # Prune linear layers + self.attention.query = prune_linear_layer(self.attention.query, index) + self.attention.key = prune_linear_layer(self.attention.key, index) + self.attention.value = prune_linear_layer(self.attention.value, index) + self.output.dense = prune_linear_layer(self.output.dense, index, dim=1) + + # Update hyper params and store pruned heads + self.attention.num_attention_heads = self.attention.num_attention_heads - len(heads) + self.attention.all_head_size = self.attention.attention_head_size * self.attention.num_attention_heads + self.pruned_heads = self.pruned_heads.union(heads) + + def forward( + self, + hidden_states: torch.Tensor, + attention_mask: Optional[torch.FloatTensor] = None, + head_mask: Optional[torch.FloatTensor] = None, + encoder_hidden_states: Optional[torch.FloatTensor] = None, + encoder_attention_mask: Optional[torch.FloatTensor] = None, + past_key_value: Optional[Tuple[Tuple[torch.FloatTensor]]] = None, + output_attentions: Optional[bool] = False, + ) -> Tuple[torch.Tensor]: + self_outputs = self.attention( + hidden_states, + attention_mask, + head_mask, + encoder_hidden_states, + encoder_attention_mask, + past_key_value, + output_attentions, + ) + attention_output = self.output(self_outputs[0], hidden_states) + outputs = (attention_output,) + self_outputs[1:] # add attentions if we output them + return outputs + + +# Copied from transformers.models.bert.modeling_bert.BertIntermediate with Bert->Blip2QFormer +class Blip2QFormerIntermediate(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->Blip2QFormer +class Blip2QFormerOutput(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 + + +class Blip2QFormerLayer(nn.Module): + def __init__(self, config, layer_idx): + super().__init__() + self.chunk_size_feed_forward = config.chunk_size_feed_forward + self.seq_len_dim = 1 + self.attention = Blip2QFormerAttention(config) + + self.layer_idx = layer_idx + + if layer_idx % config.cross_attention_frequency == 0: + self.crossattention = Blip2QFormerAttention(config, is_cross_attention=True) + self.has_cross_attention = True + else: + self.has_cross_attention = False + + if config.use_qformer_text_input: + self.intermediate = Blip2QFormerIntermediate(config) + self.output = Blip2QFormerOutput(config) + + self.intermediate_query = Blip2QFormerIntermediate(config) + self.output_query = Blip2QFormerOutput(config) + + def forward( + self, + hidden_states, + attention_mask=None, + head_mask=None, + encoder_hidden_states=None, + encoder_attention_mask=None, + past_key_value=None, + output_attentions=False, + query_length=0, + ): + # decoder uni-directional self-attention cached key/values tuple is at positions 1,2 + self_attn_past_key_value = past_key_value[:2] if past_key_value is not None else None + self_attention_outputs = self.attention( + hidden_states, + attention_mask, + head_mask, + output_attentions=output_attentions, + past_key_value=self_attn_past_key_value, + ) + attention_output = self_attention_outputs[0] + outputs = self_attention_outputs[1:-1] + + present_key_value = self_attention_outputs[-1] + + if query_length > 0: + query_attention_output = attention_output[:, :query_length, :] + + if self.has_cross_attention: + if encoder_hidden_states is None: + raise ValueError("encoder_hidden_states must be given for cross-attention layers") + cross_attention_outputs = self.crossattention( + query_attention_output, + attention_mask, + head_mask, + encoder_hidden_states, + encoder_attention_mask, + output_attentions=output_attentions, + ) + query_attention_output = cross_attention_outputs[0] + # add cross attentions if we output attention weights + outputs = outputs + cross_attention_outputs[1:-1] + + layer_output = apply_chunking_to_forward( + self.feed_forward_chunk_query, + self.chunk_size_feed_forward, + self.seq_len_dim, + query_attention_output, + ) + + if attention_output.shape[1] > query_length: + layer_output_text = apply_chunking_to_forward( + self.feed_forward_chunk, + self.chunk_size_feed_forward, + self.seq_len_dim, + attention_output[:, query_length:, :], + ) + layer_output = torch.cat([layer_output, layer_output_text], dim=1) + else: + layer_output = apply_chunking_to_forward( + self.feed_forward_chunk, + self.chunk_size_feed_forward, + self.seq_len_dim, + attention_output, + ) + outputs = (layer_output,) + outputs + + outputs = outputs + (present_key_value,) + + return outputs + + def feed_forward_chunk(self, attention_output): + intermediate_output = self.intermediate(attention_output) + layer_output = self.output(intermediate_output, attention_output) + return layer_output + + def feed_forward_chunk_query(self, attention_output): + intermediate_output = self.intermediate_query(attention_output) + layer_output = self.output_query(intermediate_output, attention_output) + return layer_output + + +class Blip2QFormerEncoder(nn.Module): + def __init__(self, config): + super().__init__() + self.config = config + self.layer = nn.ModuleList( + [Blip2QFormerLayer(config, layer_idx) for layer_idx in range(config.num_hidden_layers)] + ) + self.gradient_checkpointing = False + + def forward( + self, + hidden_states, + attention_mask=None, + head_mask=None, + encoder_hidden_states=None, + encoder_attention_mask=None, + past_key_values=None, + use_cache=None, + output_attentions=False, + output_hidden_states=False, + return_dict=True, + query_length=0, + ): + all_hidden_states = () if output_hidden_states else None + all_self_attentions = () if output_attentions else None + all_cross_attentions = () if output_attentions else None + + next_decoder_cache = () if use_cache else None + + for i in range(self.config.num_hidden_layers): + layer_module = self.layer[i] + if output_hidden_states: + all_hidden_states = all_hidden_states + (hidden_states,) + + layer_head_mask = head_mask[i] if head_mask is not None else None + past_key_value = past_key_values[i] if past_key_values is not None else None + + if getattr(self.config, "gradient_checkpointing", False) and self.training: + if use_cache: + logger.warning( + "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..." + ) + use_cache = False + layer_outputs = self._gradient_checkpointing_func( + layer_module.__call__, + hidden_states, + attention_mask, + layer_head_mask, + encoder_hidden_states, + encoder_attention_mask, + ) + else: + layer_outputs = layer_module( + hidden_states, + attention_mask, + layer_head_mask, + encoder_hidden_states, + encoder_attention_mask, + past_key_value, + output_attentions, + query_length, + ) + + hidden_states = layer_outputs[0] + if use_cache: + next_decoder_cache += (layer_outputs[-1],) + if output_attentions: + all_self_attentions = all_self_attentions + (layer_outputs[1],) + if layer_module.has_cross_attention: + all_cross_attentions = all_cross_attentions + (layer_outputs[2],) + + if output_hidden_states: + all_hidden_states = all_hidden_states + (hidden_states,) + + if not return_dict: + return tuple( + v + for v in [ + hidden_states, + next_decoder_cache, + all_hidden_states, + all_self_attentions, + all_cross_attentions, + ] + if v is not None + ) + return BaseModelOutputWithPastAndCrossAttentions( + last_hidden_state=hidden_states, + past_key_values=next_decoder_cache, + hidden_states=all_hidden_states, + attentions=all_self_attentions, + cross_attentions=all_cross_attentions, + ) + + +class Blip2TextEmbeddings(nn.Module): + """Construct the embeddings from word and position 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.position_embeddings = nn.Embedding(config.max_position_embeddings, config.hidden_size) + + # 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.position_embedding_type = getattr(config, "position_embedding_type", "absolute") + + def forward( + self, + input_ids: Optional[torch.FloatTensor] = None, + position_ids: Optional[torch.LongTensor] = None, + query_embeds: Optional[torch.FloatTensor] = None, + ) -> torch.Tensor: + if input_ids is not None: + seq_length = input_ids.size()[1] + else: + seq_length = 0 + + if position_ids is None: + position_ids = self.position_ids[:, :seq_length] + + if input_ids is not None: + input_ids = input_ids.to(self.word_embeddings.weight.device) + embeddings = self.word_embeddings(input_ids) + if self.position_embedding_type == "absolute": + position_embeddings = self.position_embeddings(position_ids) + embeddings += position_embeddings + + if query_embeds is not None: + # `query_embeds` are kept in fp32 when we use it with Qformer + if query_embeds.dtype != embeddings.dtype: + query_embeds = query_embeds.to(embeddings.dtype) + embeddings = torch.cat((query_embeds, embeddings), dim=1) + else: + embeddings = query_embeds + + return embeddings + + +@add_start_docstrings( + """ + BLIP-2 Querying Transformer (Q-Former). + """, + BLIP_2_QFORMER_START_DOCSTRING, +) +class Blip2QFormerModel(Blip2PreTrainedModel): + def __init__(self, config: Blip2QFormerConfig): + super().__init__(config) + self.config = config + + self.layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) + self.dropout = nn.Dropout(config.hidden_dropout_prob) + + self.encoder = Blip2QFormerEncoder(config) + + self.post_init() + + def get_input_embeddings(self): + return self.embeddings.word_embeddings + + def set_input_embeddings(self, value): + self.embeddings.word_embeddings = value + + def _prune_heads(self, heads_to_prune): + """ + Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base + class PreTrainedModel + """ + for layer, heads in heads_to_prune.items(): + self.encoder.layer[layer].attention.prune_heads(heads) + + def get_extended_attention_mask( + self, + attention_mask: torch.Tensor, + input_shape: Tuple[int], + device: torch.device, + has_query: bool = False, + ) -> torch.Tensor: + """ + Makes broadcastable attention and causal masks so that future and masked tokens are ignored. + + Arguments: + attention_mask (`torch.Tensor`): + Mask with ones indicating tokens to attend to, zeros for tokens to ignore. + input_shape (`Tuple[int]`): + The shape of the input to the model. + device (`torch.device`): + The device of the input to the model. + + Returns: + `torch.Tensor` The extended attention mask, with a the same dtype as `attention_mask.dtype`. + """ + # We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length] + # ourselves in which case we just need to make it broadcastable to all heads. + if attention_mask.dim() == 3: + extended_attention_mask = attention_mask[:, None, :, :] + elif attention_mask.dim() == 2: + # Provided a padding mask of dimensions [batch_size, seq_length] + # - the model is an encoder, so make the mask broadcastable to [batch_size, num_heads, seq_length, seq_length] + extended_attention_mask = attention_mask[:, None, None, :] + else: + raise ValueError( + "Wrong shape for input_ids (shape {}) or attention_mask (shape {})".format( + input_shape, attention_mask.shape + ) + ) + + # Since attention_mask is 1.0 for positions we want to attend and 0.0 for + # masked positions, this operation will create a tensor which is 0.0 for + # positions we want to attend and -10000.0 for masked positions. + # Since we are adding it to the raw scores before the softmax, this is + # effectively the same as removing these entirely. + extended_attention_mask = extended_attention_mask.to(dtype=self.dtype) # fp16 compatibility + extended_attention_mask = (1.0 - extended_attention_mask) * -10000.0 + return extended_attention_mask + + @add_start_docstrings_to_model_forward(BLIP2_QFORMER_INPUTS_DOCSTRING) + @replace_return_docstrings( + output_type=BaseModelOutputWithPoolingAndCrossAttentions, config_class=Blip2QFormerConfig + ) + def forward( + self, + query_embeds: torch.FloatTensor, + query_length: Optional[int] = None, + attention_mask: Optional[torch.FloatTensor] = None, + head_mask: Optional[torch.FloatTensor] = None, + encoder_hidden_states: Optional[torch.FloatTensor] = None, + encoder_attention_mask: Optional[torch.FloatTensor] = None, + past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None, + use_cache: Optional[bool] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple[torch.Tensor], BaseModelOutputWithPoolingAndCrossAttentions]: + r""" + Returns: + """ + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + # past_key_values_length + past_key_values_length = ( + past_key_values[0][0].shape[2] - self.config.query_length if past_key_values is not None else 0 + ) + + query_length = ( + query_length if query_length is not None else query_embeds.shape[1] if query_embeds is not None else 0 + ) + + embedding_output = self.layernorm(query_embeds) + embedding_output = self.dropout(embedding_output) + + input_shape = embedding_output.size()[:-1] + batch_size, seq_length = input_shape + device = embedding_output.device + + if attention_mask is None: + attention_mask = torch.ones(((batch_size, seq_length + past_key_values_length)), device=device) + + # We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length] + # ourselves in which case we just need to make it broadcastable to all heads. + extended_attention_mask = self.get_extended_attention_mask(attention_mask, input_shape, device) + + # If a 2D or 3D attention mask is provided for the cross-attention + # we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length] + if encoder_hidden_states is not None: + # Qformer and latent query tokens are kept in fp32. We cast `encoder_hidden_states` if not fp32 already + if encoder_hidden_states.dtype != query_embeds.dtype: + encoder_hidden_states = encoder_hidden_states.to(query_embeds.dtype) + + if isinstance(encoder_hidden_states, list): + encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states[0].size() + else: + encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size() + encoder_hidden_shape = (encoder_batch_size, encoder_sequence_length) + + if isinstance(encoder_attention_mask, list): + encoder_extended_attention_mask = [self.invert_attention_mask(mask) for mask in encoder_attention_mask] + elif encoder_attention_mask is None: + encoder_attention_mask = torch.ones(encoder_hidden_shape, device=device) + encoder_extended_attention_mask = self.invert_attention_mask(encoder_attention_mask) + else: + encoder_extended_attention_mask = self.invert_attention_mask(encoder_attention_mask) + else: + encoder_extended_attention_mask = None + + # Prepare head mask if needed + # 1.0 in head_mask indicate we keep the head + # attention_probs has shape bsz x n_heads x N x N + # input head_mask has shape [num_heads] or [num_hidden_layers x num_heads] + # and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length] + head_mask = self.get_head_mask(head_mask, self.config.num_hidden_layers) + + encoder_outputs = self.encoder( + embedding_output, + attention_mask=extended_attention_mask, + head_mask=head_mask, + encoder_hidden_states=encoder_hidden_states, + encoder_attention_mask=encoder_extended_attention_mask, + past_key_values=past_key_values, + use_cache=use_cache, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + query_length=query_length, + ) + sequence_output = encoder_outputs[0] + pooled_output = sequence_output[:, 0, :] + + if not return_dict: + return (sequence_output, pooled_output) + encoder_outputs[1:] + + 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, + ) + + +@add_start_docstrings( + """ + BLIP-2 Model for generating text and image features. The model consists of a vision encoder, Querying Transformer + (Q-Former) and a language model. + """, + BLIP_2_START_DOCSTRING, +) +class Blip2Model(Blip2PreTrainedModel): + config_class = Blip2Config + main_input_name = "pixel_values" + _keep_in_fp32_modules = ["query_tokens", "qformer"] + + def __init__(self, config: Blip2Config): + super().__init__(config) + + self.vision_model = Blip2VisionModel(config.vision_config) + + self.query_tokens = nn.Parameter(torch.zeros(1, config.num_query_tokens, config.qformer_config.hidden_size)) + self.qformer = Blip2QFormerModel(config.qformer_config) + + self.language_projection = nn.Linear(config.qformer_config.hidden_size, config.text_config.hidden_size) + if config.use_decoder_only_language_model: + language_model = AutoModelForCausalLM.from_config(config.text_config) + else: + language_model = AutoModelForSeq2SeqLM.from_config(config.text_config) + + # Update _tied_weights_keys using the base model used. + if language_model._tied_weights_keys is not None: + self._tied_weights_keys = [f"language_model.{k}" for k in language_model._tied_weights_keys] + + self.language_model = language_model + + # Initialize weights and apply final processing + self.post_init() + + def get_input_embeddings(self): + return self.language_model.get_input_embeddings() + + def set_input_embeddings(self, value): + self.language_model.set_input_embeddings(value) + + def set_output_embeddings(self, new_embeddings): + self.language_model.set_output_embeddings(new_embeddings) + + def get_output_embeddings(self) -> nn.Module: + return self.language_model.get_output_embeddings() + + def get_encoder(self): + return self.language_model.get_encoder() + + def get_decoder(self): + return self.language_model.get_decoder() + + def _tie_weights(self): + if not self.config.use_decoder_only_language_model: + self.language_model.encoder.embed_tokens = self.language_model.shared + self.language_model.decoder.embed_tokens = self.language_model.shared + + @add_start_docstrings_to_model_forward(BLIP_2_TEXT_INPUTS_DOCSTRING) + def get_text_features( + self, + input_ids: Optional[torch.Tensor] = None, + attention_mask: Optional[torch.Tensor] = None, + decoder_input_ids: Optional[torch.Tensor] = None, + decoder_attention_mask: Optional[torch.Tensor] = None, + labels: Optional[torch.Tensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ): + r""" + Returns: + text_outputs (`CausalLMOutputWithPast`, or `tuple(torch.FloatTensor)` if `return_dict=False`): + The language model outputs. If `return_dict=True`, the output is a [`CausalLMOutputWithPast`] that + contains the language model logits, the past key values and the hidden states if + `output_hidden_states=True`. + Examples: + ```python + >>> import torch + >>> from transformers import AutoTokenizer, Blip2Model + + >>> model = Blip2Model.from_pretrained("Salesforce/blip2-opt-2.7b") + + >>> tokenizer = AutoTokenizer.from_pretrained("Salesforce/blip2-opt-2.7b") + >>> inputs = tokenizer(["a photo of a cat"], padding=True, return_tensors="pt") + >>> text_features = model.get_text_features(**inputs) + ```""" + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + if self.config.use_decoder_only_language_model: + text_outputs = self.language_model( + input_ids=input_ids, + attention_mask=attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + else: + inputs_embeds = self.language_model.get_input_embeddings()(input_ids) + + text_outputs = self.language_model( + inputs_embeds=inputs_embeds, + attention_mask=attention_mask, + decoder_input_ids=decoder_input_ids, + decoder_attention_mask=decoder_attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + labels=labels, + ) + + return text_outputs + + @add_start_docstrings_to_model_forward(BLIP_2_VISION_INPUTS_DOCSTRING) + def get_image_features( + self, + pixel_values: Optional[torch.FloatTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + interpolate_pos_encoding: bool = False, + ): + r""" + Returns: + vision_outputs (`BaseModelOutputWithPooling` or tuple of `torch.FloatTensor`): + The vision model outputs. If `return_dict=True`, the output is a [`BaseModelOutputWithPooling`] that + contains the image features, the pooled image features and the hidden states if + `output_hidden_states=True`. + Examples: + ```python + >>> import torch + >>> from PIL import Image + >>> import requests + >>> from transformers import AutoProcessor, Blip2Model + + >>> model = Blip2Model.from_pretrained("Salesforce/blip2-opt-2.7b") + + >>> processor = AutoProcessor.from_pretrained("Salesforce/blip2-opt-2.7b") + >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" + >>> image = Image.open(requests.get(url, stream=True).raw) + >>> inputs = processor(images=image, return_tensors="pt") + >>> image_outputs = model.get_image_features(**inputs) + ```""" + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + vision_outputs = self.vision_model( + pixel_values=pixel_values, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + interpolate_pos_encoding=interpolate_pos_encoding, + ) + + return vision_outputs + + @add_start_docstrings_to_model_forward(BLIP_2_INPUTS_DOCSTRING) + def get_qformer_features( + self, + pixel_values: Optional[torch.FloatTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + interpolate_pos_encoding: bool = False, + ): + r""" + Returns: + vision_outputs (`BaseModelOutputWithPooling` or tuple of `torch.FloatTensor`): + The vision model outputs. If `return_dict=True`, the output is a [`BaseModelOutputWithPooling`] that + contains the image features, the pooled image features and the hidden states if + `output_hidden_states=True`. + Examples: + ```python + >>> import torch + >>> from PIL import Image + >>> import requests + >>> from transformers import Blip2Processor, Blip2Model + + >>> processor = Blip2Processor.from_pretrained("Salesforce/blip2-opt-2.7b") + >>> model = Blip2Model.from_pretrained("Salesforce/blip2-opt-2.7b") + + >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" + >>> image = Image.open(requests.get(url, stream=True).raw) + >>> inputs = processor(images=image, return_tensors="pt") + >>> qformer_outputs = model.get_qformer_features(**inputs) + ```""" + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + vision_outputs = self.vision_model( + pixel_values=pixel_values, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + interpolate_pos_encoding=interpolate_pos_encoding, + ) + + image_embeds = vision_outputs[0] + + # step 2: forward the query tokens through the QFormer, using the image embeddings for cross-attention + image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device) + + query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1) + query_outputs = self.qformer( + query_embeds=query_tokens, + encoder_hidden_states=image_embeds, + encoder_attention_mask=image_attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + return query_outputs + + @add_start_docstrings_to_model_forward(BLIP_2_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Blip2ForConditionalGenerationModelOutput, config_class=Blip2VisionConfig) + def forward( + self, + pixel_values: torch.FloatTensor, + input_ids: torch.FloatTensor, + attention_mask: Optional[torch.LongTensor] = None, + decoder_input_ids: Optional[torch.LongTensor] = None, + decoder_attention_mask: Optional[torch.LongTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + labels: Optional[torch.LongTensor] = None, + return_dict: Optional[bool] = None, + interpolate_pos_encoding: bool = False, + ) -> Union[Tuple, Blip2ForConditionalGenerationModelOutput]: + r""" + Returns: + + Examples: + + ```python + >>> from PIL import Image + >>> import requests + >>> from transformers import Blip2Processor, Blip2Model + >>> import torch + + >>> device = "cuda" if torch.cuda.is_available() else "cpu" + + >>> processor = Blip2Processor.from_pretrained("Salesforce/blip2-opt-2.7b") + >>> model = Blip2Model.from_pretrained("Salesforce/blip2-opt-2.7b", torch_dtype=torch.float16) + >>> model.to(device) # doctest: +IGNORE_RESULT + + >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" + >>> image = Image.open(requests.get(url, stream=True).raw) + + >>> prompt = "Question: how many cats are there? Answer:" + >>> inputs = processor(images=image, text=prompt, return_tensors="pt").to(device, torch.float16) + + >>> outputs = model(**inputs) + ```""" + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + # step 1: forward the images through the vision encoder, + # to get image embeddings of shape (batch_size, seq_len, hidden_size) + vision_outputs = self.vision_model( + pixel_values=pixel_values, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + interpolate_pos_encoding=interpolate_pos_encoding, + ) + image_embeds = vision_outputs[0] + + # step 2: forward the query tokens through the QFormer, using the image embeddings for cross-attention + image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device) + + query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1) + query_outputs = self.qformer( + query_embeds=query_tokens, + encoder_hidden_states=image_embeds, + encoder_attention_mask=image_attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + query_output = query_outputs[0] + + # Qformer is kept in fp32, we downcast the output back if needed + if query_output.dtype != image_embeds.dtype: + query_output = query_output.to(image_embeds.dtype) + + # step 3: use the language model, conditioned on the query outputs and the prompt + language_model_inputs = self.language_projection(query_output) + language_model_attention_mask = torch.ones( + language_model_inputs.size()[:-1], dtype=torch.long, device=language_model_inputs.device + ) + inputs_embeds = self.language_model.get_input_embeddings()(input_ids) + inputs_embeds = torch.cat([language_model_inputs, inputs_embeds], dim=1) + + if attention_mask is None: + attention_mask = torch.ones_like(input_ids) + expected_device = language_model_attention_mask.device + attention_mask = torch.cat([language_model_attention_mask, attention_mask.to(expected_device)], dim=1) + + if self.config.use_decoder_only_language_model: + outputs = self.language_model( + inputs_embeds=inputs_embeds, + attention_mask=attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + logits = outputs.logits if return_dict else outputs[0] + loss = None + # we compute the loss here since we need to take into account the sequence length of the query embeds + if labels is not None: + labels = labels.to(logits.device) + logits = logits[:, -labels.size(1) :, :] + # Shift so that tokens < n predict n + shift_logits = logits[..., :-1, :].contiguous() + shift_labels = labels[..., 1:].contiguous().to(logits.device) + + # Flatten the tokens + loss_fct = CrossEntropyLoss(reduction="mean") + + loss = loss_fct(shift_logits.view(-1, self.config.text_config.vocab_size), shift_labels.view(-1)) + else: + outputs = self.language_model( + inputs_embeds=inputs_embeds, + attention_mask=attention_mask, + decoder_input_ids=decoder_input_ids, + decoder_attention_mask=decoder_attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=True, # toggle for easier access to loss/logits below + labels=labels, + ) + loss = outputs.loss + logits = outputs.logits + outputs = outputs.to_tuple() if not return_dict else outputs + + if not return_dict: + output = (logits, vision_outputs, query_outputs, outputs) + return ((loss,) + output) if loss is not None else output + + return Blip2ForConditionalGenerationModelOutput( + loss=loss, + logits=logits, + vision_outputs=vision_outputs, + qformer_outputs=query_outputs, + language_model_outputs=outputs, + ) + + +@add_start_docstrings( + """ + BLIP-2 Text Model with a projection layer on top (a linear layer on top of the pooled output). + """, + BLIP_2_START_DOCSTRING, +) +class Blip2TextModelWithProjection(Blip2PreTrainedModel): + supports_gradient_checkpointing = False + _keep_in_fp32_modules = ["query_tokens", "qformer"] + + def __init__(self, config: Blip2Config): + super().__init__(config) + + self.query_tokens = nn.Parameter(torch.zeros(1, config.num_query_tokens, config.qformer_config.hidden_size)) + self.embeddings = Blip2TextEmbeddings(config.qformer_config) + self.qformer = Blip2QFormerModel(config.qformer_config) + + # text projection layer + self.text_projection = nn.Linear(config.qformer_config.hidden_size, config.image_text_hidden_size) + + # 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 + + @add_start_docstrings_to_model_forward(BLIP_2_TEXT_WITH_PROJECTION_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Blip2TextModelOutput, config_class=Blip2Config) + def forward( + self, + input_ids: Optional[torch.Tensor] = None, + attention_mask: Optional[torch.Tensor] = None, + position_ids: Optional[torch.Tensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple, Blip2TextModelOutput]: + r""" + Returns: + + Examples: + + ```python + >>> import torch + >>> from transformers import AutoProcessor, Blip2TextModelWithProjection + + >>> device = "cuda" if torch.cuda.is_available() else "cpu" + + >>> model = Blip2TextModelWithProjection.from_pretrained( + ... "Salesforce/blip2-itm-vit-g", torch_dtype=torch.float16 + ... ) + + >>> model.to(device) # doctest: +IGNORE_RESULT + + >>> processor = AutoProcessor.from_pretrained("Salesforce/blip2-itm-vit-g") + + >>> inputs = processor(text=["a photo of a cat", "a photo of a dog"], return_tensors="pt").to(device) + + >>> outputs = model(**inputs) + >>> text_embeds = outputs.text_embeds + >>> print(text_embeds.shape) + torch.Size([2, 7, 256]) + ```""" + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + query_embeds = self.embeddings( + input_ids=input_ids, + position_ids=position_ids, + ) + + text_outputs = self.qformer( + query_embeds=query_embeds, + query_length=0, + attention_mask=attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + pooled_output = text_outputs[0] if not return_dict else text_outputs.last_hidden_state + + text_embeds = self.text_projection(pooled_output) + text_embeds = nn.functional.normalize(text_embeds, dim=-1) + + if not return_dict: + outputs = (text_embeds, text_outputs[0]) + text_outputs[2:] + return tuple(output for output in outputs if output is not None) + + return Blip2TextModelOutput( + text_embeds=text_embeds, + last_hidden_state=text_outputs.last_hidden_state, + hidden_states=text_outputs.hidden_states, + attentions=text_outputs.attentions, + ) + + +@add_start_docstrings( + """ + BLIP-2 Vision Model with a projection layer on top (a linear layer on top of the pooled output). + """, + BLIP_2_START_DOCSTRING, +) +class Blip2VisionModelWithProjection(Blip2PreTrainedModel): + main_input_name = "pixel_values" + _keep_in_fp32_modules = ["query_tokens", "qformer"] + + def __init__(self, config: Blip2Config): + super().__init__(config) + + self.vision_model = Blip2VisionModel(config.vision_config) + + self.query_tokens = nn.Parameter(torch.zeros(1, config.num_query_tokens, config.qformer_config.hidden_size)) + self.qformer = Blip2QFormerModel(config.qformer_config) + + # vision projection layer + self.vision_projection = nn.Linear(config.qformer_config.hidden_size, config.image_text_hidden_size) + + # Initialize weights and apply final processing + self.post_init() + + def get_input_embeddings(self) -> nn.Module: + return self.vision_model.embeddings.patch_embedding + + @add_start_docstrings_to_model_forward(BLIP_2_VISION_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Blip2VisionModelOutput, config_class=Blip2Config) + def forward( + self, + pixel_values: Optional[torch.FloatTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple, Blip2VisionModelOutput]: + r""" + Returns: + + Examples: + + ```python + >>> import torch + >>> from PIL import Image + >>> import requests + >>> from transformers import AutoProcessor, Blip2VisionModelWithProjection + + >>> device = "cuda" if torch.cuda.is_available() else "cpu" + + >>> processor = AutoProcessor.from_pretrained("Salesforce/blip2-itm-vit-g") + >>> model = Blip2VisionModelWithProjection.from_pretrained( + ... "Salesforce/blip2-itm-vit-g", torch_dtype=torch.float16 + ... ) + >>> model.to(device) # doctest: +IGNORE_RESULT + + >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" + >>> image = Image.open(requests.get(url, stream=True).raw) + + >>> inputs = processor(images=image, return_tensors="pt").to(device, torch.float16) + + >>> outputs = model(**inputs) + >>> image_embeds = outputs.image_embeds + >>> print(image_embeds.shape) + torch.Size([1, 32, 256]) + ```""" + 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 + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + vision_outputs = self.vision_model( + pixel_values=pixel_values, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + pooled_output = vision_outputs[0] if not return_dict else vision_outputs.last_hidden_state + + image_attention_mask = torch.ones(pooled_output.size()[:-1], dtype=torch.long, device=pooled_output.device) + + query_tokens = self.query_tokens.expand(pooled_output.shape[0], -1, -1) + + query_outputs = self.qformer( + query_embeds=query_tokens, + encoder_hidden_states=pooled_output, + encoder_attention_mask=image_attention_mask, + return_dict=return_dict, + ) + + embeds = query_outputs[0] if not return_dict else query_outputs.last_hidden_state + image_embeds = self.vision_projection(embeds) + image_embeds = nn.functional.normalize(image_embeds, dim=-1) + + if not return_dict: + outputs = (image_embeds, vision_outputs[0]) + vision_outputs[2:] + return tuple(output for output in outputs if output is not None) + + return Blip2VisionModelOutput( + image_embeds=image_embeds, + last_hidden_state=vision_outputs.last_hidden_state, + hidden_states=vision_outputs.hidden_states, + attentions=vision_outputs.attentions, + ) + + +@add_start_docstrings( + """ + BLIP-2 Model for generating text given an image and an optional text prompt. The model consists of a vision + encoder, Querying Transformer (Q-Former) and a language model. + + One can optionally pass `input_ids` to the model, which serve as a text prompt, to make the language model continue + the prompt. Otherwise, the language model starts generating text from the [BOS] (beginning-of-sequence) token. + + + + Note that Flan-T5 checkpoints cannot be cast to float16. They are pre-trained using bfloat16. + + + """, + BLIP_2_START_DOCSTRING, +) +class Blip2ForConditionalGeneration(Blip2PreTrainedModel, GenerationMixin): + config_class = Blip2Config + main_input_name = "pixel_values" + _supports_cache_class = True + _supports_static_cache = True + _supports_quantized_cache = False # not all LM bacbones support (e.g. T5) + _keep_in_fp32_modules = ["query_tokens", "qformer"] + + def __init__(self, config: Blip2Config): + super().__init__(config) + + self.vision_model = Blip2VisionModel(config.vision_config) + + self.query_tokens = nn.Parameter(torch.zeros(1, config.num_query_tokens, config.qformer_config.hidden_size)) + self.qformer = Blip2QFormerModel(config.qformer_config) + + self.language_projection = nn.Linear(config.qformer_config.hidden_size, config.text_config.hidden_size) + if config.use_decoder_only_language_model: + language_model = AutoModelForCausalLM.from_config(config.text_config) + else: + language_model = AutoModelForSeq2SeqLM.from_config(config.text_config) + + # Update _tied_weights_keys using the base model used. + if language_model._tied_weights_keys is not None: + self._tied_weights_keys = [f"language_model.{k}" for k in language_model._tied_weights_keys] + + self.language_model = language_model + + # Initialize weights and apply final processing + self.post_init() + + def get_input_embeddings(self): + return self.language_model.get_input_embeddings() + + def set_input_embeddings(self, value): + self.language_model.set_input_embeddings(value) + + def set_output_embeddings(self, new_embeddings): + self.language_model.set_output_embeddings(new_embeddings) + + def get_output_embeddings(self) -> nn.Module: + return self.language_model.get_output_embeddings() + + def get_encoder(self): + return self.language_model.get_encoder() + + def get_decoder(self): + return self.language_model.get_decoder() + + def _tie_weights(self): + if not self.config.use_decoder_only_language_model: + self.language_model.encoder.embed_tokens = self.language_model.shared + self.language_model.decoder.embed_tokens = self.language_model.shared + + def _preprocess_accelerate(self): + r""" + Some pre-processing hacks to make the model `accelerate` compatible. Check + https://github.com/huggingface/transformers/pull/21707 for more details. + """ + hf_device_map = self.hf_device_map + + if len(hf_device_map) > 1 and "language_model" not in hf_device_map and torch.cuda.device_count() > 1: + # warn users about unexpected behavior when using multi-GPU + BLIP-2 + `accelerate`. + logger.warning( + "The `language_model` is not in the `hf_device_map` dictionary and you are running your script" + " in a multi-GPU environment. this may lead to unexpected behavior when using `accelerate`." + " Please pass a `device_map` that contains `language_model` to remove this warning." + " Please refer to https://github.com/huggingface/blog/blob/main/accelerate-large-models.md for" + " more details on creating a `device_map` for large models.", + ) + + if hasattr(self.language_model, "_hf_hook"): + self.language_model._hf_hook.io_same_device = True # For `generate` compatibility + + @add_start_docstrings_to_model_forward(BLIP_2_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Blip2ForConditionalGenerationModelOutput, config_class=Blip2VisionConfig) + def forward( + self, + pixel_values: torch.FloatTensor, + input_ids: torch.FloatTensor, + attention_mask: Optional[torch.LongTensor] = None, + decoder_input_ids: Optional[torch.LongTensor] = None, + decoder_attention_mask: Optional[torch.LongTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + labels: Optional[torch.LongTensor] = None, + return_dict: Optional[bool] = None, + interpolate_pos_encoding: bool = False, + use_cache: Optional[bool] = None, + ) -> Union[Tuple, Blip2ForConditionalGenerationModelOutput]: + r""" + Returns: + + Examples: + + Prepare processor, model and image input + + ```python + >>> from PIL import Image + >>> import requests + >>> from transformers import Blip2Processor, Blip2ForConditionalGeneration + >>> import torch + + >>> device = "cuda" if torch.cuda.is_available() else "cpu" + + >>> processor = Blip2Processor.from_pretrained("Salesforce/blip2-opt-2.7b") + >>> model = Blip2ForConditionalGeneration.from_pretrained( + ... "Salesforce/blip2-opt-2.7b", load_in_8bit=True, device_map={"": 0}, torch_dtype=torch.float16 + ... ) # doctest: +IGNORE_RESULT + + >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" + >>> image = Image.open(requests.get(url, stream=True).raw) + ``` + + Image captioning (without providing a text prompt): + + ```python + >>> inputs = processor(images=image, return_tensors="pt").to(device, torch.float16) + + >>> generated_ids = model.generate(**inputs) + >>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0].strip() + >>> print(generated_text) + two cats laying on a couch + ``` + + Visual question answering (prompt = question): + + ```python + >>> prompt = "Question: how many cats are there? Answer:" + >>> inputs = processor(images=image, text=prompt, return_tensors="pt").to(device="cuda", dtype=torch.float16) + + >>> generated_ids = model.generate(**inputs) + >>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0].strip() + >>> print(generated_text) + two + ``` + + Note that int8 inference is also supported through [bitsandbytes](https://github.com/TimDettmers/bitsandbytes). + This greatly reduces the amount of memory used by the model while maintaining the same performance. + + ```python + >>> model = Blip2ForConditionalGeneration.from_pretrained( + ... "Salesforce/blip2-opt-2.7b", load_in_8bit=True, device_map={"": 0}, torch_dtype=torch.bfloat16 + ... ) # doctest: +IGNORE_RESULT + + >>> inputs = processor(images=image, text=prompt, return_tensors="pt").to(device="cuda", dtype=torch.bfloat16) + + >>> generated_ids = model.generate(**inputs) + >>> generated_text = processor.batch_decode(generated_ids, skip_special_tokens=True)[0].strip() + >>> print(generated_text) + two + ```""" + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + # step 1: forward the images through the vision encoder, + # to get image embeddings of shape (batch_size, seq_len, hidden_size) + vision_outputs = self.vision_model( + pixel_values=pixel_values, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + interpolate_pos_encoding=interpolate_pos_encoding, + ) + image_embeds = vision_outputs[0] + + # step 2: forward the query tokens through the QFormer, using the image embeddings for cross-attention + image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device) + + query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1) + query_outputs = self.qformer( + query_embeds=query_tokens, + encoder_hidden_states=image_embeds, + encoder_attention_mask=image_attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + query_output = query_outputs[0] + + # Qformer is kept in fp32, we downcast the output back if needed + if query_output.dtype != image_embeds.dtype: + query_output = query_output.to(image_embeds.dtype) + + # step 3: use the language model, conditioned on the query outputs and the prompt + language_model_inputs = self.language_projection(query_output) + language_model_attention_mask = torch.ones( + language_model_inputs.size()[:-1], dtype=torch.long, device=language_model_inputs.device + ) + inputs_embeds = self.language_model.get_input_embeddings()(input_ids) + if attention_mask is None: + attention_mask = torch.ones_like(input_ids) + + # if the model already has "image_token_id" then the input is expanded to account for image embeds + # otherwise we expand manually by concating + if getattr(self.config, "image_token_id", None) is not None: + special_image_mask = (input_ids == self.config.image_token_id).unsqueeze(-1).expand_as(inputs_embeds) + language_model_inputs = language_model_inputs.to(inputs_embeds.device, inputs_embeds.dtype) + inputs_embeds = inputs_embeds.masked_scatter(special_image_mask, language_model_inputs) + else: + logger.warning_once( + "Expanding inputs for image tokens in BLIP-2 should be done in processing. " + "Please follow instruction here (https://gist.github.com/zucchini-nlp/e9f20b054fa322f84ac9311d9ab67042) to update your BLIP-2 model. " + "Using processors without these attributes in the config is deprecated and will throw an error in v4.50." + ) + inputs_embeds = torch.cat([language_model_inputs, inputs_embeds.to(language_model_inputs.device)], dim=1) + attention_mask = torch.cat( + [language_model_attention_mask, attention_mask.to(language_model_attention_mask.device)], dim=1 + ) + + if self.config.use_decoder_only_language_model: + outputs = self.language_model( + inputs_embeds=inputs_embeds, + attention_mask=attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + use_cache=use_cache, + ) + logits = outputs.logits if return_dict else outputs[0] + loss = None + # we compute the loss here since we need to take into account the sequence length of the query embeds + if labels is not None: + labels = labels.to(logits.device) + logits = logits[:, -labels.size(1) :, :] + # Shift so that tokens < n predict n + shift_logits = logits[..., :-1, :].contiguous() + shift_labels = labels[..., 1:].contiguous().to(logits.device) + + # Flatten the tokens + loss_fct = CrossEntropyLoss(reduction="mean") + + loss = loss_fct(shift_logits.view(-1, self.config.text_config.vocab_size), shift_labels.view(-1)) + else: + outputs = self.language_model( + inputs_embeds=inputs_embeds, + attention_mask=attention_mask, + decoder_input_ids=decoder_input_ids, + decoder_attention_mask=decoder_attention_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=True, # toggle for easier access to loss/logits below + labels=labels, + use_cache=use_cache, + ) + loss = outputs.loss + logits = outputs.logits + outputs = outputs.to_tuple() if not return_dict else outputs + + if not return_dict: + output = (logits, vision_outputs, query_outputs, outputs) + return ((loss,) + output) if loss is not None else output + + return Blip2ForConditionalGenerationModelOutput( + loss=loss, + logits=logits, + vision_outputs=vision_outputs, + qformer_outputs=query_outputs, + language_model_outputs=outputs, + ) + + @torch.no_grad() + def generate( + self, + pixel_values: torch.FloatTensor, + input_ids: Optional[torch.LongTensor] = None, + attention_mask: Optional[torch.LongTensor] = None, + interpolate_pos_encoding: bool = False, + **generate_kwargs, + ) -> torch.LongTensor: + """ + Overrides `generate` function to be able to use the model as a conditional generator. + + Args: + pixel_values (`torch.FloatTensor` of shape (batch_size, num_channels, height, width)): + Input images to be processed. + input_ids (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*): + The sequence used as a prompt for the generation. + attention_mask (`torch.LongTensor` of shape (batch_size, sequence_length), *optional*): + Mask to avoid performing attention on padding token indices + + Returns: + captions (list): A list of strings of length batch_size * num_captions. + """ + if hasattr(self, "hf_device_map"): + # preprocess for `accelerate` + self._preprocess_accelerate() + + batch_size = pixel_values.shape[0] + image_embeds = self.vision_model( + pixel_values, + return_dict=True, + interpolate_pos_encoding=interpolate_pos_encoding, + ).last_hidden_state + image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device) + + query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1) + query_outputs = self.qformer( + query_embeds=query_tokens, + encoder_hidden_states=image_embeds, + encoder_attention_mask=image_attention_mask, + return_dict=True, + ) + query_output = query_outputs.last_hidden_state + + # Qformer is kept in fp32, we downcast the output back if needed + if query_output.dtype != image_embeds.dtype: + query_output = query_output.to(image_embeds.dtype) + + language_model_inputs = self.language_projection(query_output) + language_attention_mask = torch.ones( + language_model_inputs.size()[:-1], dtype=torch.long, device=language_model_inputs.device + ) + + if input_ids is None: + start_tokens = [self.config.text_config.bos_token_id] + if getattr(self.config, "image_token_id", None) is not None: + start_tokens = [self.config.image_token_id] * self.config.num_query_tokens + start_tokens + input_ids = torch.tensor([start_tokens], dtype=torch.long, device=image_embeds.device) + input_ids = input_ids.repeat(batch_size, 1) + + inputs_embeds = self.get_input_embeddings()(input_ids) + if attention_mask is None: + attention_mask = torch.ones_like(input_ids) + + # if the model already has "image_token_id" then the input is expanded to account for image embeds + # otherwise we expand manually by concatenating + if getattr(self.config, "image_token_id", None) is not None: + special_image_mask = (input_ids == self.config.image_token_id).unsqueeze(-1).expand_as(inputs_embeds) + inputs_embeds[special_image_mask] = language_model_inputs.flatten() + else: + logger.warning_once( + "Expanding inputs for image tokens in BLIP-2 should be done in processing. " + "Please follow instruction here (https://gist.github.com/zucchini-nlp/e9f20b054fa322f84ac9311d9ab67042) to update your BLIP-2 model. " + "Using processors without these attributes in the config is deprecated and will throw an error in v4.50." + ) + inputs_embeds = torch.cat([language_model_inputs, inputs_embeds.to(language_model_inputs.device)], dim=1) + attention_mask = torch.cat( + [language_attention_mask, attention_mask.to(language_attention_mask.device)], dim=1 + ) + + # add image_embeds length to max_length, so that the final max_length in counted only on token embeds + # -1 is to account for the prepended BOS after `generate.` + # TODO (joao, raushan): refactor `generate` to avoid these operations with VLMs + if not self.language_model.config.is_encoder_decoder: + generate_kwargs["max_length"] = ( + generate_kwargs.get("max_length", 20) + language_model_inputs.shape[1] - 1 + ) + generate_kwargs["min_length"] = generate_kwargs.get("min_length", 0) + language_model_inputs.shape[1] + + inputs = {"inputs_embeds": inputs_embeds, "attention_mask": attention_mask} + if not self.language_model.config.is_encoder_decoder: + inputs["input_ids"] = input_ids + + outputs = self.language_model.generate(**inputs, **generate_kwargs) + return outputs + + +@add_start_docstrings( + """ + BLIP-2 Model with a vision and text projector, and a classification head on top. The model is used in the context + of image-text retrieval. Given an image and a text, the model returns the probability of the text being relevant to + the image. + """, + BLIP_2_START_DOCSTRING, +) +class Blip2ForImageTextRetrieval(Blip2PreTrainedModel): + main_input_name = "pixel_values" + _keep_in_fp32_modules = ["query_tokens", "qformer"] + + def __init__(self, config: Blip2Config): + super().__init__(config) + + self.vision_model = Blip2VisionModel(config.vision_config) + + self.query_tokens = nn.Parameter(torch.zeros(1, config.num_query_tokens, config.qformer_config.hidden_size)) + + self.embeddings = Blip2TextEmbeddings(config.qformer_config) + self.qformer = Blip2QFormerModel(config.qformer_config) + + # vision projection layer + self.vision_projection = nn.Linear(config.qformer_config.hidden_size, config.image_text_hidden_size) + + # text projection layer + self.text_projection = nn.Linear(config.qformer_config.hidden_size, config.image_text_hidden_size) + + # image text matching head + self.itm_head = nn.Linear(config.qformer_config.hidden_size, 2) + + # 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 + + @add_start_docstrings_to_model_forward(BLIP2_IMAGE_TEXT_RETRIEVAL_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Blip2ImageTextMatchingModelOutput, config_class=Blip2Config) + def forward( + self, + pixel_values: torch.FloatTensor, + input_ids: torch.LongTensor, + attention_mask: Optional[torch.LongTensor] = None, + use_image_text_matching_head: Optional[bool] = False, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple, Blip2ImageTextMatchingModelOutput]: + r""" + Returns: + + Examples: + + ```python + >>> import torch + >>> from PIL import Image + >>> import requests + >>> from transformers import AutoProcessor, Blip2ForImageTextRetrieval + + >>> device = "cuda" if torch.cuda.is_available() else "cpu" + + >>> model = Blip2ForImageTextRetrieval.from_pretrained("Salesforce/blip2-itm-vit-g", torch_dtype=torch.float16) + >>> processor = AutoProcessor.from_pretrained("Salesforce/blip2-itm-vit-g") + + >>> model.to(device) # doctest: +IGNORE_RESULT + + >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg" + >>> image = Image.open(requests.get(url, stream=True).raw) + >>> text = "two cats laying on a pink blanket" + + >>> inputs = processor(images=image, text=text, return_tensors="pt").to(device, torch.float16) + >>> itm_out = model(**inputs, use_image_text_matching_head=True) + >>> logits_per_image = torch.nn.functional.softmax(itm_out.logits_per_image, dim=1) + >>> probs = logits_per_image.softmax(dim=1) # we can take the softmax to get the label probabilities + + >>> print(f"{probs[0][0]:.1%} that image 0 is not '{text}'") + 26.9% that image 0 is not 'two cats laying on a pink blanket' + + >>> print(f"{probs[0][1]:.1%} that image 0 is '{text}'") + 73.0% that image 0 is 'two cats laying on a pink blanket' + + >>> texts = ["a photo of a cat", "a photo of a dog"] + + >>> inputs = processor(images=image, text=texts, return_tensors="pt").to(device, torch.float16) + >>> itc_out = model(**inputs, use_image_text_matching_head=False) + >>> logits_per_image = itc_out.logits_per_image # this is the image-text similarity score + >>> probs = logits_per_image.softmax(dim=1) # we can take the softmax to get the label probabilities + + >>> print(f"{probs[0][0]:.1%} that image 0 is '{texts[0]}'") + 55.3% that image 0 is 'a photo of a cat' + + >>> print(f"{probs[0][1]:.1%} that image 0 is '{texts[1]}'") + 44.7% that image 0 is 'a photo of a dog' + ``` + """ + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + 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 + ) + + vision_outputs = self.vision_model( + pixel_values=pixel_values, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + image_embeds = vision_outputs[0] + image_attention_mask = torch.ones(image_embeds.size()[:-1], dtype=torch.long, device=image_embeds.device) + + if use_image_text_matching_head: + query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1) + query_attention_mask = torch.ones(query_tokens.size()[:-1], dtype=torch.long, device=query_tokens.device) + attention_mask = torch.cat([query_attention_mask, attention_mask], dim=1) + + query_embeds = self.embeddings( + input_ids=input_ids, + query_embeds=query_tokens, + ) + + text_outputs = self.qformer( + query_embeds=query_embeds, + query_length=query_tokens.shape[1], + attention_mask=attention_mask, + encoder_hidden_states=image_embeds, + encoder_attention_mask=image_attention_mask, + return_dict=return_dict, + ) + text_embeds = text_outputs[0] if not return_dict else text_outputs.last_hidden_state + + output = self.itm_head(text_embeds[:, : query_tokens.size(1), :]) + logits_per_image = output.mean(dim=1) + logits_per_text = logits_per_image.t() + else: + query_tokens = self.query_tokens.expand(image_embeds.shape[0], -1, -1) + query_outputs = self.qformer( + query_embeds=query_tokens, + encoder_hidden_states=image_embeds, + encoder_attention_mask=image_attention_mask, + return_dict=return_dict, + ) + image_embeds = query_outputs[0] if not return_dict else query_outputs.last_hidden_state + + query_embeds = self.embeddings( + input_ids=input_ids, + ) + text_outputs = self.qformer( + query_embeds=query_embeds, + query_length=0, + attention_mask=attention_mask, + return_dict=return_dict, + ) + question_embeds = text_outputs[0] if not return_dict else text_outputs.last_hidden_state + + # normalized features + image_embeds = nn.functional.normalize(self.vision_projection(image_embeds), dim=-1) + text_embeds = nn.functional.normalize(self.text_projection(question_embeds[:, 0, :]), dim=-1) + + # cosine similarity as logits + logits_per_image = torch.matmul(image_embeds, text_embeds.t()) + logits_per_image, _ = logits_per_image.max(dim=1) + + logits_per_text = logits_per_image.t() + + if not return_dict: + output = (logits_per_image, logits_per_text, text_embeds, image_embeds, text_outputs, vision_outputs) + return output + + return Blip2ImageTextMatchingModelOutput( + logits_per_image=logits_per_image, + logits_per_text=logits_per_text, + text_embeds=text_embeds, + image_embeds=image_embeds, + text_model_output=text_outputs, + vision_model_output=vision_outputs, + ) + + +__all__ = [ + "Blip2Model", + "Blip2VisionModelWithProjection", + "Blip2QFormerModel", + "Blip2PreTrainedModel", + "Blip2ForConditionalGeneration", + "Blip2ForImageTextRetrieval", + "Blip2VisionModel", + "Blip2TextModelWithProjection", +]