Transformers documentation
BLIP-2
This model was released on 2023-01-30 and added to Hugging Face Transformers on 2023-02-09.
BLIP-2
Overview
The BLIP-2 model was proposed in BLIP-2: Bootstrapping Language-Image Pre-training with Frozen Image Encoders and Large Language Models by Junnan Li, Dongxu Li, Silvio Savarese, Steven Hoi. BLIP-2 leverages frozen pre-trained image encoders and large language models (LLMs) by training a lightweight, 12-layer Transformer encoder in between them, achieving state-of-the-art performance on various vision-language tasks. Most notably, BLIP-2 improves upon Flamingo, an 80 billion parameter model, by 8.7% on zero-shot VQAv2 with 54x fewer trainable parameters.
The abstract from the paper is the following:
The cost of vision-and-language pre-training has become increasingly prohibitive due to end-to-end training of large-scale models. This paper proposes BLIP-2, a generic and efficient pre-training strategy that bootstraps vision-language pre-training from off-the-shelf frozen pre-trained image encoders and frozen large language models. BLIP-2 bridges the modality gap with a lightweight Querying Transformer, which is pre-trained in two stages. The first stage bootstraps vision-language representation learning from a frozen image encoder. The second stage bootstraps vision-to-language generative learning from a frozen language model. BLIP-2 achieves state-of-the-art performance on various vision-language tasks, despite having significantly fewer trainable parameters than existing methods. For example, our model outperforms Flamingo80B by 8.7% on zero-shot VQAv2 with 54x fewer trainable parameters. We also demonstrate the model’s emerging capabilities of zero-shot image-to-text generation that can follow natural language instructions.
BLIP-2 architecture. Taken from the original paper. This model was contributed by nielsr. The original code can be found here.
Usage tips
- BLIP-2 can be used for conditional text generation given an image and an optional text prompt. At inference time, it’s recommended to use the
generatemethod. - One can use Blip2Processor to prepare images for the model, and decode the predicted tokens ID’s back to text.
BLIP models after release v4.46 will raise warnings about adding
processor.num_query_tokens = {{num_query_tokens}}and expand model embeddings layer to add special<image>token. It is strongly recommended to add the attributes to the processor if you own the model checkpoint, or open a PR if it is not owned by you. Adding these attributes means that BLIP will add the number of query tokens required per image and expand the text with as many<image>placeholders as there will be query tokens. Usually it is around 500 tokens per image, so make sure that the text is not truncated as otherwise there will be failure when merging the embeddings. The attributes can be obtained from model config, asmodel.config.num_query_tokensand model embeddings expansion can be done by following this link.
Resources
A list of official Hugging Face and community (indicated by 🌎) resources to help you get started with BLIP-2.
- Demo notebooks for BLIP-2 for image captioning, visual question answering (VQA) and chat-like conversations can be found here.
If you’re interested in submitting a resource to be included here, please feel free to open a Pull Request and we’ll review it! The resource should ideally demonstrate something new instead of duplicating an existing resource.
Blip2Config
class transformers.Blip2Config
< source >( vision_config = None qformer_config = None text_config = None num_query_tokens = 32 image_text_hidden_size = 256 image_token_index = None **kwargs )
Parameters
- vision_config (
dict, optional) — Dictionary of configuration options used to initialize Blip2VisionConfig. - qformer_config (
dict, optional) — Dictionary of configuration options used to initialize Blip2QFormerConfig. - text_config (
dict, optional) — Dictionary of configuration options used to initialize any PretrainedConfig. - num_query_tokens (
int, optional, defaults to 32) — The number of query tokens passed through the Transformer. - image_text_hidden_size (
int, optional, defaults to 256) — Dimensionality of the hidden state of the image-text fusion layer. - image_token_index (
int, optional) — Token index of special image token. - kwargs (optional) — Dictionary of keyword arguments.
Blip2Config is the configuration class to store the configuration of a Blip2ForConditionalGeneration. It is used to instantiate a BLIP-2 model according to the specified arguments, defining the vision model, Q-Former model and language model configs. Instantiating a configuration with the defaults will yield a similar configuration to that of the BLIP-2 Salesforce/blip2-opt-2.7b architecture.
Configuration objects inherit from PretrainedConfig and can be used to control the model outputs. Read the documentation from PretrainedConfig for more information.
Example:
>>> from transformers import (
... Blip2VisionConfig,
... Blip2QFormerConfig,
... OPTConfig,
... Blip2Config,
... Blip2ForConditionalGeneration,
... )
>>> # Initializing a Blip2Config with Salesforce/blip2-opt-2.7b style configuration
>>> configuration = Blip2Config()
>>> # Initializing a Blip2ForConditionalGeneration (with random weights) from the Salesforce/blip2-opt-2.7b style configuration
>>> model = Blip2ForConditionalGeneration(configuration)
>>> # Accessing the model configuration
>>> configuration = model.config
>>> # We can also initialize a Blip2Config from a Blip2VisionConfig, Blip2QFormerConfig and any PretrainedConfig
>>> # Initializing BLIP-2 vision, BLIP-2 Q-Former and language model configurations
>>> vision_config = Blip2VisionConfig()
>>> qformer_config = Blip2QFormerConfig()
>>> text_config = OPTConfig()
>>> config = Blip2Config.from_text_vision_configs(vision_config, qformer_config, text_config)from_vision_qformer_text_configs
< source >( vision_config: Blip2VisionConfig qformer_config: Blip2QFormerConfig text_config: typing.Optional[transformers.configuration_utils.PretrainedConfig] = None **kwargs ) → Blip2Config
Parameters
- vision_config (
dict) — Dictionary of configuration options used to initialize Blip2VisionConfig. - qformer_config (
dict) — Dictionary of configuration options used to initialize Blip2QFormerConfig. - text_config (
dict, optional) — Dictionary of configuration options used to initialize any PretrainedConfig.
Returns
An instance of a configuration object
Instantiate a Blip2Config (or a derived class) from a BLIP-2 vision model, Q-Former and language model configurations.
Blip2VisionConfig
class transformers.Blip2VisionConfig
< source >( hidden_size = 1408 intermediate_size = 6144 num_hidden_layers = 39 num_attention_heads = 16 image_size = 224 patch_size = 14 hidden_act = 'gelu' layer_norm_eps = 1e-06 attention_dropout = 0.0 initializer_range = 1e-10 qkv_bias = True **kwargs )
Parameters
- hidden_size (
int, optional, defaults to 1408) — Dimensionality of the encoder layers and the pooler layer. - intermediate_size (
int, optional, defaults to 6144) — Dimensionality of the “intermediate” (i.e., feed-forward) layer in the Transformer encoder. - num_hidden_layers (
int, optional, defaults to 39) — Number of hidden layers in the Transformer encoder. - num_attention_heads (
int, optional, defaults to 16) — Number of attention heads for each attention layer in the Transformer encoder. - image_size (
int, optional, defaults to 224) — The size (resolution) of each image. - patch_size (
int, optional, defaults to 14) — The size (resolution) of each patch. - hidden_act (
strorfunction, optional, defaults to"gelu") — The non-linear activation function (function or string) in the encoder and pooler. If string,"gelu","relu","selu"and"gelu_new""gelu"are supported. layer_norm_eps (float, optional, defaults to 1e-5): The epsilon used by the layer normalization layers. - attention_dropout (
float, optional, defaults to 0.0) — The dropout ratio for the attention probabilities. - initializer_range (
float, optional, defaults to 0.02) — The standard deviation of the truncated_normal_initializer for initializing all weight matrices. - qkv_bias (
bool, optional, defaults toTrue) — Whether to add a bias to the queries and values in the self-attention layers.
This is the configuration class to store the configuration of a Blip2VisionModel. It is used to instantiate a BLIP-2 vision encoder according to the specified arguments, defining the model architecture. Instantiating a configuration defaults will yield a similar configuration to that of the BLIP-2 Salesforce/blip2-opt-2.7b architecture.
Configuration objects inherit from PretrainedConfig and can be used to control the model outputs. Read the documentation from PretrainedConfig for more information.
Example:
>>> from transformers import Blip2VisionConfig, Blip2VisionModel
>>> # Initializing a Blip2VisionConfig with Salesforce/blip2-opt-2.7b style configuration
>>> configuration = Blip2VisionConfig()
>>> # Initializing a Blip2VisionModel (with random weights) from the Salesforce/blip2-opt-2.7b style configuration
>>> model = Blip2VisionModel(configuration)
>>> # Accessing the model configuration
>>> configuration = model.configBlip2QFormerConfig
class transformers.Blip2QFormerConfig
< source >( vocab_size = 30522 hidden_size = 768 num_hidden_layers = 12 num_attention_heads = 12 intermediate_size = 3072 hidden_act = 'gelu' hidden_dropout_prob = 0.1 attention_probs_dropout_prob = 0.1 max_position_embeddings = 512 initializer_range = 0.02 layer_norm_eps = 1e-12 pad_token_id = 0 position_embedding_type = 'absolute' cross_attention_frequency = 2 encoder_hidden_size = 1408 use_qformer_text_input = False **kwargs )
Parameters
- vocab_size (
int, optional, defaults to 30522) — Vocabulary size of the Q-Former model. Defines the number of different tokens that can be represented by theinputs_idspassed when calling the model. - hidden_size (
int, optional, defaults to 768) — Dimensionality of the encoder layers and the pooler layer. - num_hidden_layers (
int, optional, defaults to 12) — Number of hidden layers in the Transformer encoder. - num_attention_heads (
int, optional, defaults to 12) — Number of attention heads for each attention layer in the Transformer encoder. - intermediate_size (
int, optional, defaults to 3072) — Dimensionality of the “intermediate” (often named feed-forward) layer in the Transformer encoder. - hidden_act (
strorCallable, optional, defaults to"gelu") — The non-linear activation function (function or string) in the encoder and pooler. If string,"gelu","relu","silu"and"gelu_new"are supported. - hidden_dropout_prob (
float, optional, defaults to 0.1) — The dropout probability for all fully connected layers in the embeddings, encoder, and pooler. - attention_probs_dropout_prob (
float, optional, defaults to 0.1) — The dropout ratio for the attention probabilities. - max_position_embeddings (
int, optional, defaults to 512) — The maximum sequence length that this model might ever be used with. Typically set this to something large just in case (e.g., 512 or 1024 or 2048). - initializer_range (
float, optional, defaults to 0.02) — The standard deviation of the truncated_normal_initializer for initializing all weight matrices. - layer_norm_eps (
float, optional, defaults to 1e-12) — The epsilon used by the layer normalization layers. - pad_token_id (
int, optional, defaults to 0) — Index to be used for padding token. - position_embedding_type (
str, optional, defaults to"absolute") — Type of position embedding. Choose one of"absolute","relative_key","relative_key_query". For positional embeddings use"absolute". For more information on"relative_key", please refer to Self-Attention with Relative Position Representations (Shaw et al.). For more information on"relative_key_query", please refer to Method 4 in Improve Transformer Models with Better Relative Position Embeddings (Huang et al.). - cross_attention_frequency (
int, optional, defaults to 2) — The frequency of adding cross-attention to the Transformer layers. - encoder_hidden_size (
int, optional, defaults to 1408) — The hidden size of the hidden states for cross-attention. - use_qformer_text_input (
bool, optional, defaults toFalse) — Whether to use BERT-style embeddings.
This is the configuration class to store the configuration of a Blip2QFormerModel. It is used to instantiate a BLIP-2 Querying Transformer (Q-Former) model according to the specified arguments, defining the model architecture. Instantiating a configuration with the defaults will yield a similar configuration to that of the BLIP-2 Salesforce/blip2-opt-2.7b architecture. Configuration objects inherit from PretrainedConfig and can be used to control the model outputs. Read the documentation from PretrainedConfig for more information.
Note that Blip2QFormerModel is very similar to BertLMHeadModel with interleaved cross-attention.
Examples:
>>> from transformers import Blip2QFormerConfig, Blip2QFormerModel
>>> # Initializing a BLIP-2 Salesforce/blip2-opt-2.7b style configuration
>>> configuration = Blip2QFormerConfig()
>>> # Initializing a model (with random weights) from the Salesforce/blip2-opt-2.7b style configuration
>>> model = Blip2QFormerModel(configuration)
>>> # Accessing the model configuration
>>> configuration = model.configBlip2Processor
class transformers.Blip2Processor
< source >( image_processor tokenizer num_query_tokens = None **kwargs )
Parameters
- image_processor (
BlipImageProcessor) — An instance of BlipImageProcessor. The image processor is a required input. - tokenizer (
AutoTokenizer) — An instance of [‘PreTrainedTokenizer`]. The tokenizer is a required input. - num_query_tokens (
int, optional) — Number of tokens used by the Qformer as queries, should be same as in model’s config.
Constructs a BLIP-2 processor which wraps a BLIP image processor and an OPT/T5 tokenizer into a single processor.
BlipProcessor offers all the functionalities of BlipImageProcessor and AutoTokenizer. See the docstring
of __call__() and decode() for more information.
Blip2VisionModel
class transformers.Blip2VisionModel
< source >( config: Blip2VisionConfig )
Parameters
- config (Blip2VisionConfig) — 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 from_pretrained() method to load the model weights.
The bare Blip 2 Model outputting raw hidden-states without any specific head on top.
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( pixel_values: typing.Optional[torch.FloatTensor] = None interpolate_pos_encoding: bool = False **kwargs: typing_extensions.Unpack[transformers.utils.generic.TransformersKwargs] ) → transformers.modeling_outputs.BaseModelOutputWithPooling or tuple(torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size), optional) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images). - interpolate_pos_encoding (
bool, defaults toFalse) — Whether to interpolate the pre-trained position encodings.
Returns
transformers.modeling_outputs.BaseModelOutputWithPooling or tuple(torch.FloatTensor)
A transformers.modeling_outputs.BaseModelOutputWithPooling or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
-
last_hidden_state (
torch.FloatTensorof shape(batch_size, sequence_length, hidden_size)) — Sequence of hidden-states at the output of the last layer of the model. -
pooler_output (
torch.FloatTensorof shape(batch_size, hidden_size)) — Last layer hidden-state of the first token of the sequence (classification token) after further processing through the layers used for the auxiliary pretraining task. E.g. for BERT-family of models, this returns the classification token after processing through a linear layer and a tanh activation function. The linear layer weights are trained from the next sentence prediction (classification) objective during pretraining. -
hidden_states (
tuple(torch.FloatTensor), optional, returned whenoutput_hidden_states=Trueis passed or whenconfig.output_hidden_states=True) — Tuple oftorch.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 whenoutput_attentions=Trueis passed or whenconfig.output_attentions=True) — Tuple oftorch.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.
The Blip2VisionModel forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Blip2QFormerModel
class transformers.Blip2QFormerModel
< source >( config: Blip2QFormerConfig )
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 from_pretrained() method to load the model weights.
BLIP-2 Querying Transformer (Q-Former).
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( query_embeds: FloatTensor query_length: typing.Optional[int] = None attention_mask: typing.Optional[torch.FloatTensor] = None head_mask: typing.Optional[torch.FloatTensor] = None encoder_hidden_states: typing.Optional[torch.FloatTensor] = None encoder_attention_mask: typing.Optional[torch.FloatTensor] = None **kwargs: typing_extensions.Unpack[transformers.utils.generic.TransformersKwargs] ) → transformers.modeling_outputs.BaseModelOutputWithPoolingAndCrossAttentions or tuple(torch.FloatTensor)
Parameters
- query_embeds (
torch.FloatTensorof 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.FloatTensorof 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.
- head_mask (
torch.FloatTensorof 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.FloatTensorof 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.FloatTensorof 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.
Returns
transformers.modeling_outputs.BaseModelOutputWithPoolingAndCrossAttentions or tuple(torch.FloatTensor)
A transformers.modeling_outputs.BaseModelOutputWithPoolingAndCrossAttentions or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
-
last_hidden_state (
torch.FloatTensorof shape(batch_size, sequence_length, hidden_size)) — Sequence of hidden-states at the output of the last layer of the model. -
pooler_output (
torch.FloatTensorof shape(batch_size, hidden_size)) — Last layer hidden-state of the first token of the sequence (classification token) after further processing through the layers used for the auxiliary pretraining task. E.g. for BERT-family of models, this returns the classification token after processing through a linear layer and a tanh activation function. The linear layer weights are trained from the next sentence prediction (classification) objective during pretraining. -
hidden_states (
tuple(torch.FloatTensor), optional, returned whenoutput_hidden_states=Trueis passed or whenconfig.output_hidden_states=True) — Tuple oftorch.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 whenoutput_attentions=Trueis passed or whenconfig.output_attentions=True) — Tuple oftorch.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.
-
cross_attentions (
tuple(torch.FloatTensor), optional, returned whenoutput_attentions=Trueandconfig.add_cross_attention=Trueis passed or whenconfig.output_attentions=True) — Tuple oftorch.FloatTensor(one for each layer) of shape(batch_size, num_heads, sequence_length, sequence_length).Attentions weights of the decoder’s cross-attention layer, after the attention softmax, used to compute the weighted average in the cross-attention heads.
-
past_key_values (
Cache, optional, returned whenuse_cache=Trueis passed or whenconfig.use_cache=True) — It is a Cache instance. For more details, see our kv cache guide.Contains pre-computed hidden-states (key and values in the self-attention blocks and optionally if
config.is_encoder_decoder=Truein the cross-attention blocks) that can be used (seepast_key_valuesinput) to speed up sequential decoding.
The Blip2QFormerModel forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Blip2Model
class transformers.Blip2Model
< source >( config: Blip2Config )
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 from_pretrained() method to load the model weights.
BLIP-2 Model for generating text and image features. The model consists of a vision encoder, Querying Transformer (Q-Former) and a language model.
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( pixel_values: FloatTensor input_ids: FloatTensor attention_mask: typing.Optional[torch.LongTensor] = None decoder_input_ids: typing.Optional[torch.LongTensor] = None decoder_attention_mask: typing.Optional[torch.LongTensor] = None labels: typing.Optional[torch.LongTensor] = None interpolate_pos_encoding: bool = False **kwargs: typing_extensions.Unpack[transformers.utils.generic.TransformersKwargs] ) → transformers.models.blip_2.modeling_blip_2.Blip2ForConditionalGenerationModelOutput or tuple(torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size)) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images). - input_ids (
torch.FloatTensorof shape(batch_size, sequence_length)) — Indices of input sequence tokens in the vocabulary. Padding will be ignored by default.Indices can be obtained using AutoTokenizer. See PreTrainedTokenizer.encode() and PreTrainedTokenizer.call() for details.
- attention_mask (
torch.LongTensorof 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.
- decoder_input_ids (
torch.LongTensorof 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.
- decoder_attention_mask (
torch.BoolTensorof shape(batch_size, target_sequence_length), optional) — Default behavior: generate a tensor that ignores pad tokens indecoder_input_ids. Causal mask will also be used by default.Only relevant in case an encoder-decoder language model (like T5) is used.
- labels (
torch.LongTensorof shape(batch_size, sequence_length), optional) — Labels for computing the masked language modeling loss. Indices should either be in[0, ..., config.vocab_size]or -100 (seeinput_idsdocstring). Tokens with indices set to-100are ignored (masked), the loss is only computed for the tokens with labels in[0, ..., config.vocab_size]. - interpolate_pos_encoding (
bool, defaults toFalse) — Whether to interpolate the pre-trained position encodings.
Returns
transformers.models.blip_2.modeling_blip_2.Blip2ForConditionalGenerationModelOutput or tuple(torch.FloatTensor)
A transformers.models.blip_2.modeling_blip_2.Blip2ForConditionalGenerationModelOutput or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
- loss (
torch.FloatTensor, optional, returned whenlabelsis provided,torch.FloatTensorof shape(1,)) — Language modeling loss from the language model. - logits (
torch.FloatTensorof shape(batch_size, sequence_length, config.vocab_size)) — Prediction scores of the language modeling head of the language model. - vision_outputs (
torch.FloatTensor, optional, defaults toNone) — Outputs of the vision encoder. - qformer_outputs (
tuple[torch.FloatTensor], optional, defaults toNone) — Outputs of the Q-Former (Querying Transformer). - language_model_outputs (
CausalLMOutputWithPastorSeq2SeqLMOutput) — Outputs of the language model.
The Blip2Model forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Examples:
>>> 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", dtype=torch.float16)
>>> model.to(device)
>>> 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)get_text_features
< source >( input_ids: Tensor attention_mask: typing.Optional[torch.Tensor] = None decoder_input_ids: typing.Optional[torch.Tensor] = None decoder_attention_mask: typing.Optional[torch.Tensor] = None labels: typing.Optional[torch.Tensor] = None legacy_output: bool = True ) → text_outputs (CausalLMOutputWithPast or torch.FloatTensor)
Parameters
- input_ids (
torch.Tensorof shape(batch_size, sequence_length)) — Indices of input sequence tokens in the vocabulary. Padding will be ignored by default.Indices can be obtained using AutoTokenizer. See PreTrainedTokenizer.encode() and PreTrainedTokenizer.call() for details.
- attention_mask (
torch.Tensorof 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.
- decoder_input_ids (
torch.LongTensorof 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.
T5 uses the
pad_token_idas the starting token fordecoder_input_idsgeneration. Ifpast_key_valuesis used, optionally only the lastdecoder_input_idshave to be input (seepast_key_values).To know more on how to prepare
decoder_input_idsfor pretraining take a look at T5 Training. - decoder_attention_mask (
torch.BoolTensorof shape(batch_size, target_sequence_length), optional) — Default behavior: generate a tensor that ignores pad tokens indecoder_input_ids. Causal mask will also be used by default. - labels (
torch.Tensorof shape(batch_size, sequence_length), optional) — Labels for computing the masked language modeling loss. Indices should either be in[0, ..., config.vocab_size]or -100 (seeinput_idsdocstring). Tokens with indices set to-100are ignored (masked), the loss is only computed for the tokens with labels in[0, ..., config.vocab_size]. - legacy_output (
bool, optional, defaults toTrue) — Whether to return a model output object or a tensor of features.
Returns
text_outputs (CausalLMOutputWithPast or torch.FloatTensor)
The language model outputs. If legacy_output=False, the output is a torch.FloatTensor.
Examples:
>>> 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")
>>> with torch.inference_mode():
... text_features = model.get_text_features(**inputs)get_image_features
< source >( pixel_values: FloatTensor interpolate_pos_encoding: bool = False legacy_output: bool = True ) → vision_outputs (BaseModelOutputWithPooling or torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size)) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images). - interpolate_pos_encoding (
bool, defaults toFalse) — Whether to interpolate the pre-trained position encodings. - legacy_output (
bool, optional, defaults toTrue) — Whether to return a model output object or a tensor of features.
Returns
vision_outputs (BaseModelOutputWithPooling or torch.FloatTensor)
The vision model outputs. If legacy_output=False, the output is a torch.FloatTensor.
Examples:
>>> import torch
>>> from transformers import AutoProcessor, Blip2Model
>>> from transformers.image_utils import load_image
>>> 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 = load_image(url)
>>> inputs = processor(images=image, return_tensors="pt")
>>> with torch.inference_mode():
... image_outputs = model.get_image_features(**inputs)get_qformer_features
< source >( pixel_values: FloatTensor interpolate_pos_encoding: bool = False legacy_output: bool = True ) → qformer_outputs (BaseModelOutputWithPooling or torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size)) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images). - interpolate_pos_encoding (
bool, defaults toFalse) — Whether to interpolate the pre-trained position encodings. - legacy_output (
bool, optional, defaults toTrue) — Whether to return a model output object or a tensor of features.
Returns
qformer_outputs (BaseModelOutputWithPooling or torch.FloatTensor)
The Q-Former outputs. If legacy_output=False, the output is a torch.FloatTensor.
Examples:
>>> import torch
>>> from transformers import AutoProcessor, Blip2Model
>>> from transformers.image_utils import load_image
>>> 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 = load_image(url)
>>> inputs = processor(images=image, return_tensors="pt")
>>> with torch.inference_mode():
... qformer_outputs = model.get_qformer_features(**inputs)Blip2ForConditionalGeneration
class transformers.Blip2ForConditionalGeneration
< source >( config: Blip2Config )
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 from_pretrained() method to load the model weights.
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.
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( pixel_values: FloatTensor input_ids: LongTensor attention_mask: typing.Optional[torch.LongTensor] = None decoder_input_ids: typing.Optional[torch.LongTensor] = None decoder_attention_mask: typing.Optional[torch.LongTensor] = None inputs_embeds: typing.Optional[torch.FloatTensor] = None labels: typing.Optional[torch.LongTensor] = None interpolate_pos_encoding: bool = False **kwargs: typing_extensions.Unpack[transformers.utils.generic.TransformersKwargs] ) → transformers.models.blip_2.modeling_blip_2.Blip2ForConditionalGenerationModelOutput or tuple(torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size)) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images). - input_ids (
torch.LongTensorof 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. - attention_mask (
torch.LongTensorof 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.
- decoder_input_ids (
torch.LongTensorof 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.
- decoder_attention_mask (
torch.BoolTensorof shape(batch_size, target_sequence_length), optional) — Default behavior: generate a tensor that ignores pad tokens indecoder_input_ids. Causal mask will also be used by default.Only relevant in case an encoder-decoder language model (like T5) is used.
- inputs_embeds (
torch.FloatTensorof shape(batch_size, sequence_length, hidden_size), optional) — Optionally, instead of passinginput_idsyou can choose to directly pass an embedded representation. This is useful if you want more control over how to convertinput_idsindices into associated vectors than the model’s internal embedding lookup matrix. - labels (
torch.LongTensorof shape(batch_size, sequence_length), optional) — Labels for computing the masked language modeling loss. Indices should either be in[0, ..., config.vocab_size]or -100 (seeinput_idsdocstring). Tokens with indices set to-100are ignored (masked), the loss is only computed for the tokens with labels in[0, ..., config.vocab_size]. - interpolate_pos_encoding (
bool, defaults toFalse) — Whether to interpolate the pre-trained position encodings.
Returns
transformers.models.blip_2.modeling_blip_2.Blip2ForConditionalGenerationModelOutput or tuple(torch.FloatTensor)
A transformers.models.blip_2.modeling_blip_2.Blip2ForConditionalGenerationModelOutput or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
- loss (
torch.FloatTensor, optional, returned whenlabelsis provided,torch.FloatTensorof shape(1,)) — Language modeling loss from the language model. - logits (
torch.FloatTensorof shape(batch_size, sequence_length, config.vocab_size)) — Prediction scores of the language modeling head of the language model. - vision_outputs (
torch.FloatTensor, optional, defaults toNone) — Outputs of the vision encoder. - qformer_outputs (
tuple[torch.FloatTensor], optional, defaults toNone) — Outputs of the Q-Former (Querying Transformer). - language_model_outputs (
CausalLMOutputWithPastorSeq2SeqLMOutput) — Outputs of the language model.
The Blip2ForConditionalGeneration forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Examples:
Prepare processor, model and image input
>>> 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}, 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):
>>> 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 couchVisual question answering (prompt = question):
>>> 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)
twoNote that int8 inference is also supported through bitsandbytes. This greatly reduces the amount of memory used by the model while maintaining the same performance.
>>> model = Blip2ForConditionalGeneration.from_pretrained(
... "Salesforce/blip2-opt-2.7b", load_in_8bit=True, device_map={"": 0}, 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)
twogenerate
< source >( pixel_values: FloatTensor input_ids: typing.Optional[torch.LongTensor] = None attention_mask: typing.Optional[torch.LongTensor] = None inputs_embeds: typing.Optional[torch.FloatTensor] = None interpolate_pos_encoding: bool = False **generate_kwargs ) → captions (list)
Parameters
- pixel_values (
torch.FloatTensorof shape (batch_size, num_channels, height, width)) — Input images to be processed. - input_ids (
torch.LongTensorof shape (batch_size, sequence_length), optional) — The sequence used as a prompt for the generation. - attention_mask (
torch.LongTensorof shape (batch_size, sequence_length), optional) — Mask to avoid performing attention on padding token indices - inputs_embeds (
torch.FloatTensorof shape(batch_size, sequence_length, hidden_size)) — Embedded representation of the inputs. Should be float, not int tokens. - interpolate_pos_encoding (
bool, optional, defaults toFalse) — Whether to interpolate the positional encoding of the image embeddings.
Returns
captions (list)
A list of strings of length batch_size * num_captions.
Overrides generate function to be able to use the model as a conditional generator.
Blip2ForImageTextRetrieval
class transformers.Blip2ForImageTextRetrieval
< source >( config: Blip2Config )
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 from_pretrained() method to load the model weights.
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.
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( pixel_values: FloatTensor input_ids: LongTensor attention_mask: typing.Optional[torch.LongTensor] = None use_image_text_matching_head: typing.Optional[bool] = False output_attentions: typing.Optional[bool] = None output_hidden_states: typing.Optional[bool] = None return_dict: typing.Optional[bool] = None ) → transformers.models.blip_2.modeling_blip_2.Blip2ImageTextMatchingModelOutput or tuple(torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size)) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images). - input_ids (
torch.LongTensorof 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. - attention_mask (
torch.LongTensorof 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.
- 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. Seeattentionsunder returned tensors for more detail. - output_hidden_states (
bool, optional) — Whether or not to return the hidden states of all layers. Seehidden_statesunder returned tensors for more detail. - return_dict (
bool, optional) — Whether or not to return a ModelOutput instead of a plain tuple.
Returns
transformers.models.blip_2.modeling_blip_2.Blip2ImageTextMatchingModelOutput or tuple(torch.FloatTensor)
A transformers.models.blip_2.modeling_blip_2.Blip2ImageTextMatchingModelOutput or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
- loss (
torch.FloatTensorof shape(1,), optional, returned whenreturn_lossisTrue) — Contrastive loss for image-text similarity. - logits_per_image (
torch.FloatTensorof shape(image_batch_size, text_batch_size)) — The scaled dot product scores betweenimage_embedsandtext_embeds. This represents the image-text similarity scores. - logits_per_text (
torch.FloatTensorof shape(text_batch_size, image_batch_size)) — The scaled dot product scores betweentext_embedsandimage_embeds. This represents the text-image similarity scores. - text_embeds (
torch.FloatTensorof shape(batch_size, output_dim) — The text embeddings obtained by applying the projection layer to the pooled output. - image_embeds (
torch.FloatTensorof shape(batch_size, output_dim) — The image embeddings obtained by applying the projection layer to the pooled output. - text_model_output (
<class '~modeling_outputs.BaseModelOutputWithPooling'>.text_model_output, defaults toNone) — The output of the Blip2QFormerModel. - vision_model_output (
<class '~modeling_outputs.BaseModelOutputWithPooling'>.vision_model_output, defaults toNone) — The output of the Blip2VisionModel.
The Blip2ForImageTextRetrieval forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Examples:
>>> 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", dtype=torch.float16)
>>> processor = AutoProcessor.from_pretrained("Salesforce/blip2-itm-vit-g")
>>> model.to(device)
>>> 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'Blip2TextModelWithProjection
class transformers.Blip2TextModelWithProjection
< source >( config: Blip2Config )
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 from_pretrained() method to load the model weights.
The Blip 2 Model with a projection layer on top (a linear layer on top of the pooled output).
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( input_ids: typing.Optional[torch.Tensor] = None attention_mask: typing.Optional[torch.Tensor] = None position_ids: typing.Optional[torch.Tensor] = None **kwargs: typing_extensions.Unpack[transformers.utils.generic.TransformersKwargs] ) → transformers.models.blip_2.modeling_blip_2.Blip2TextModelOutput or tuple(torch.FloatTensor)
Parameters
- input_ids (
torch.Tensorof shape(batch_size, sequence_length), optional) — Indices of input sequence tokens in the vocabulary. Padding will be ignored by default.Indices can be obtained using AutoTokenizer. See PreTrainedTokenizer.encode() and PreTrainedTokenizer.call() for details.
- attention_mask (
torch.Tensorof 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.
- position_ids (
torch.Tensorof shape(batch_size, sequence_length), optional) — Indices of positions of each input sequence tokens in the position embeddings. Selected in the range[0, config.n_positions - 1].
Returns
transformers.models.blip_2.modeling_blip_2.Blip2TextModelOutput or tuple(torch.FloatTensor)
A transformers.models.blip_2.modeling_blip_2.Blip2TextModelOutput or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
-
text_embeds (
torch.FloatTensorof shape(batch_size, output_dim)optional returned when model is initialized withwith_projection=True) — The text embeddings obtained by applying the projection layer to the pooler_output. -
last_hidden_state (
torch.FloatTensorof shape(batch_size, sequence_length, hidden_size), optional, defaults toNone) — Sequence of hidden-states at the output of the last layer of the model. -
hidden_states (
tuple[torch.FloatTensor, ...], optional, returned whenoutput_hidden_states=Trueis passed or whenconfig.output_hidden_states=True) — Tuple oftorch.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 whenoutput_attentions=Trueis passed or whenconfig.output_attentions=True) — Tuple oftorch.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.
The Blip2TextModelWithProjection forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Examples:
>>> 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", dtype=torch.float16
... )
>>> model.to(device)
>>> 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])Blip2VisionModelWithProjection
class transformers.Blip2VisionModelWithProjection
< source >( config: Blip2Config )
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 from_pretrained() method to load the model weights.
The Blip 2 Model with a projection layer on top (a linear layer on top of the pooled output).
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 subclass. Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage and behavior.
forward
< source >( pixel_values: typing.Optional[torch.FloatTensor] = None **kwargs: typing_extensions.Unpack[transformers.utils.generic.TransformersKwargs] ) → transformers.models.blip_2.modeling_blip_2.Blip2VisionModelOutput or tuple(torch.FloatTensor)
Parameters
- pixel_values (
torch.FloatTensorof shape(batch_size, num_channels, image_size, image_size), optional) — The tensors corresponding to the input images. Pixel values can be obtained using BlipImageProcessor. See BlipImageProcessor.call() for details (Blip2Processor uses BlipImageProcessor for processing images).
Returns
transformers.models.blip_2.modeling_blip_2.Blip2VisionModelOutput or tuple(torch.FloatTensor)
A transformers.models.blip_2.modeling_blip_2.Blip2VisionModelOutput or a tuple of
torch.FloatTensor (if return_dict=False is passed or when config.return_dict=False) comprising various
elements depending on the configuration (Blip2Config) and inputs.
-
image_embeds (
torch.FloatTensorof shape(batch_size, output_dim)optional returned when model is initialized withwith_projection=True) — The image embeddings obtained by applying the projection layer to the pooler_output. -
last_hidden_state (
torch.FloatTensorof shape(batch_size, sequence_length, hidden_size), optional, defaults toNone) — Sequence of hidden-states at the output of the last layer of the model. -
hidden_states (
tuple[torch.FloatTensor, ...], optional, returned whenoutput_hidden_states=Trueis passed or whenconfig.output_hidden_states=True) — Tuple oftorch.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 whenoutput_attentions=Trueis passed or whenconfig.output_attentions=True) — Tuple oftorch.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.
The Blip2VisionModelWithProjection forward method, overrides the __call__ special method.
Although the recipe for forward pass needs to be defined within this function, one should call the
Moduleinstance afterwards instead of this since the former takes care of running the pre and post processing steps while the latter silently ignores them.
Examples:
>>> import torch
>>> from transformers import AutoProcessor, Blip2VisionModelWithProjection
>>> from transformers.image_utils import load_image
>>> 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", dtype=torch.float16
... )
>>> model.to(device)
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = load_image(url)
>>> inputs = processor(images=image, return_tensors="pt").to(device, torch.float16)
>>> with torch.inference_mode():
... outputs = model(**inputs)
>>> image_embeds = outputs.image_embeds
>>> print(image_embeds.shape)
torch.Size([1, 32, 256])