text-generation-inference/server/text_generation_server/models/custom_modeling/clip.py
Nicolas Patry 4634b00c2a
Adding Llava-Next (Llava 1.6) with full support. (#1709)
# What does this PR do?

- Changed all models to extract `embed_tokens` in order to enable llava
to separately call the embeddings and the core model layers.
- Added VlmCausalLM to inherit from FlashMistral in order to be
maximally supported. The only added logics sits on top and parses images
into pixel values, preallocates input_ids space for the image
embeddings, and passes them for the model.
- Added Clip for the vision tower.
- Didn't add flash for the vision tower since there's no padding anyway.
- Added heuristic (potentially incomplete) to calculate number of
features *before* calculating the clip patches (allows for easier logic
reuse of the LLM under the hood).


Still needs to be done:

- [x] Implement the image parsing in the controller side, to avoid
downloading n times per TP shard and also refusing requests too large
early and avoid issues where the truncation actually truncates the
image.
- [ ] Make sure it works with quantization properly.
- [x] Make sure it works with TP>1



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2024-04-09 21:32:00 +02:00

828 lines
31 KiB
Python

from typing import Optional, Tuple, Union
import torch
from torch import nn
from transformers.activations import ACT2FN
from transformers.modeling_attn_mask_utils import (
_create_4d_causal_attention_mask,
_prepare_4d_attention_mask,
)
from transformers.modeling_outputs import (
BaseModelOutput,
BaseModelOutputWithPooling,
ImageClassifierOutput,
)
from transformers import CLIPConfig, CLIPTextConfig, CLIPVisionConfig
from text_generation_server.utils.layers import (
TensorParallelEmbedding,
TensorParallelColumnLinear,
TensorParallelRowLinear,
)
class CLIPVisionEmbeddings(nn.Module):
def __init__(self, prefix, config: CLIPVisionConfig, weights):
super().__init__()
self.config = config
self.embed_dim = config.hidden_size
self.image_size = config.image_size
self.patch_size = config.patch_size
# TODO Should we TP this ?
self.class_embedding = weights.get_tensor(f"{prefix}.class_embedding")
self.patch_embedding = nn.Conv2d(
in_channels=config.num_channels,
out_channels=self.embed_dim,
kernel_size=self.patch_size,
stride=self.patch_size,
bias=False,
)
self.patch_embedding.weight = nn.Parameter(
weights.get_tensor(f"{prefix}.patch_embedding.weight"), requires_grad=False
)
self.num_patches = (self.image_size // self.patch_size) ** 2
self.num_positions = self.num_patches + 1
self.position_embedding = TensorParallelEmbedding(
prefix=f"{prefix}.position_embedding", weights=weights
)
self.register_buffer(
"position_ids",
torch.arange(self.num_positions, device=weights.device).expand((1, -1)),
persistent=False,
)
def forward(self, pixel_values: torch.FloatTensor) -> torch.Tensor:
batch_size = pixel_values.shape[0]
target_dtype = self.patch_embedding.weight.dtype
patch_embeds = self.patch_embedding(
pixel_values.to(dtype=target_dtype)
) # shape = [*, width, grid, grid]
patch_embeds = patch_embeds.flatten(2).transpose(1, 2)
class_embeds = self.class_embedding.expand(batch_size, 1, -1)
embeddings = torch.cat([class_embeds, patch_embeds], dim=1)
embeddings = embeddings + self.position_embedding(self.position_ids)
return embeddings
class CLIPTextEmbeddings(nn.Module):
def __init__(self, config: CLIPTextConfig):
super().__init__()
embed_dim = config.hidden_size
self.token_embedding = nn.Embedding(config.vocab_size, embed_dim)
self.position_embedding = nn.Embedding(
config.max_position_embeddings, embed_dim
)
# 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,
)
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
position_ids: Optional[torch.LongTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
) -> torch.Tensor:
seq_length = (
input_ids.shape[-1] if input_ids is not None else inputs_embeds.shape[-2]
)
if position_ids is None:
position_ids = self.position_ids[:, :seq_length]
if inputs_embeds is None:
inputs_embeds = self.token_embedding(input_ids)
position_embeddings = self.position_embedding(position_ids)
embeddings = inputs_embeds + position_embeddings
return embeddings
class CLIPAttention(nn.Module):
"""Multi-headed attention from 'Attention Is All You Need' paper"""
def __init__(self, prefix, config, weights):
super().__init__()
self.config = config
self.embed_dim = config.hidden_size
self.num_heads = config.num_attention_heads
self.head_size = self.embed_dim // self.num_heads
if self.head_size * 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.num_heads = self.num_heads // weights.process_group.size()
self.embed_dim = self.embed_dim // weights.process_group.size()
self.scale = self.head_size**-0.5
self.dropout = config.attention_dropout
self.qkv = TensorParallelColumnLinear.load_multi(
config,
prefixes=[f"{prefix}.q_proj", f"{prefix}.k_proj", f"{prefix}.v_proj"],
dim=0,
weights=weights,
bias=True,
)
self.out_proj = TensorParallelRowLinear.load(
config,
prefix=f"{prefix}.out_proj",
weights=weights,
bias=True,
)
def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
return (
tensor.view(bsz, seq_len, self.num_heads, self.head_size)
.transpose(1, 2)
.contiguous()
)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
causal_attention_mask: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
"""Input shape: Batch x Time x Channel"""
bsz, tgt_len, _ = hidden_states.size()
# get query proj
qkv = self.qkv(hidden_states)
query_states, key_states, value_states = qkv.split(
[
self.head_size * self.num_heads,
]
* 3,
dim=2,
)
query_states = query_states * self.scale
key_states = self._shape(key_states, -1, bsz)
value_states = self._shape(value_states, -1, bsz)
proj_shape = (bsz * self.num_heads, -1, self.head_size)
query_states = self._shape(query_states, tgt_len, bsz).view(*proj_shape)
key_states = key_states.view(*proj_shape)
value_states = value_states.view(*proj_shape)
src_len = key_states.size(1)
attn_weights = torch.bmm(query_states, key_states.transpose(1, 2))
if attn_weights.size() != (bsz * self.num_heads, tgt_len, src_len):
raise ValueError(
f"Attention weights should be of size {(bsz * self.num_heads, tgt_len, src_len)}, but is"
f" {attn_weights.size()}"
)
# apply the causal_attention_mask first
if causal_attention_mask is not None:
if causal_attention_mask.size() != (bsz, 1, tgt_len, src_len):
raise ValueError(
f"Attention mask should be of size {(bsz, 1, tgt_len, src_len)}, but is"
f" {causal_attention_mask.size()}"
)
attn_weights = (
attn_weights.view(bsz, self.num_heads, tgt_len, src_len)
+ causal_attention_mask
)
attn_weights = attn_weights.view(bsz * self.num_heads, tgt_len, src_len)
if attention_mask is not None:
if attention_mask.size() != (bsz, 1, tgt_len, src_len):
raise ValueError(
f"Attention mask should be of size {(bsz, 1, tgt_len, src_len)}, but is {attention_mask.size()}"
)
attn_weights = (
attn_weights.view(bsz, self.num_heads, tgt_len, src_len)
+ attention_mask
)
attn_weights = attn_weights.view(bsz * self.num_heads, tgt_len, src_len)
attn_weights = nn.functional.softmax(attn_weights, dim=-1)
attn_probs = nn.functional.dropout(
attn_weights, p=self.dropout, training=self.training
)
attn_output = torch.bmm(attn_probs, value_states)
if attn_output.size() != (bsz * self.num_heads, tgt_len, self.head_size):
raise ValueError(
f"`attn_output` should be of size {(bsz, self.num_heads, tgt_len, self.head_size)}, but is"
f" {attn_output.size()}"
)
attn_output = attn_output.view(bsz, self.num_heads, tgt_len, self.head_size)
attn_output = attn_output.transpose(1, 2)
attn_output = attn_output.reshape(bsz, tgt_len, self.embed_dim)
attn_output = self.out_proj(attn_output)
return attn_output, None
class CLIPMLP(nn.Module):
def __init__(self, prefix, config, weights):
super().__init__()
self.config = config
self.activation_fn = ACT2FN[config.hidden_act]
self.fc1 = TensorParallelColumnLinear.load(
prefix=f"{prefix}.fc1", config=config, weights=weights, bias=True
)
self.fc2 = TensorParallelRowLinear.load(
prefix=f"{prefix}.fc2", config=config, weights=weights, bias=True
)
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
class CLIPEncoderLayer(nn.Module):
def __init__(self, prefix, config: CLIPConfig, weights):
super().__init__()
self.embed_dim = config.hidden_size
self.self_attn = CLIPAttention(
prefix=f"{prefix}.self_attn", config=config, weights=weights
)
self.layer_norm1 = nn.LayerNorm.load(
prefix=f"{prefix}.layer_norm1", weights=weights, eps=config.layer_norm_eps
)
self.mlp = CLIPMLP(prefix=f"{prefix}.mlp", config=config, weights=weights)
self.layer_norm2 = nn.LayerNorm.load(
prefix=f"{prefix}.layer_norm2", weights=weights, eps=config.layer_norm_eps
)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: torch.Tensor,
causal_attention_mask: torch.Tensor,
):
"""
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,)`.
"""
residual = hidden_states
hidden_states = self.layer_norm1(hidden_states)
hidden_states, attn_weights = self.self_attn(
hidden_states=hidden_states,
attention_mask=attention_mask,
causal_attention_mask=causal_attention_mask,
)
hidden_states = residual + hidden_states
residual = hidden_states
hidden_states = self.layer_norm2(hidden_states)
hidden_states = self.mlp(hidden_states)
hidden_states = residual + hidden_states
return hidden_states
class CLIPPreTrainedModel(nn.Module):
"""
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
models.
"""
config_class = CLIPConfig
base_model_prefix = "clip"
supports_gradient_checkpointing = True
CLIP_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 ([`CLIPConfig`]): 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.
"""
CLIP_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)
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]`.
[What are position IDs?](../glossary#position-ids)
"""
CLIP_VISION_INPUTS_DOCSTRING = r"""
Args:
pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`):
Pixel values. Padding will be ignored by default should you provide it. Pixel values can be obtained using
[`AutoImageProcessor`]. See [`CLIPImageProcessor.__call__`] for details.
"""
CLIP_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]`.
[What are position IDs?](../glossary#position-ids)
pixel_values (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)`):
Pixel values. Padding will be ignored by default should you provide it. Pixel values can be obtained using
[`AutoImageProcessor`]. See [`CLIPImageProcessor.__call__`] for details.
return_loss (`bool`, *optional*):
Whether or not to return the contrastive loss.
"""
class CLIPEncoder(nn.Module):
"""
Transformer encoder consisting of `config.num_hidden_layers` self attention layers. Each layer is a
[`CLIPEncoderLayer`].
Args:
config: CLIPConfig
"""
def __init__(self, prefix, config: CLIPConfig, weights):
super().__init__()
self.config = config
self.layers = nn.ModuleList(
[
CLIPEncoderLayer(
prefix=f"{prefix}.layers.{i}", config=config, weights=weights
)
for i in range(config.num_hidden_layers)
]
)
def forward(
self,
inputs_embeds,
attention_mask: Optional[torch.Tensor] = None,
causal_attention_mask: Optional[torch.Tensor] = None,
):
r"""
Args:
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`):
Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation.
This is useful if you want more control over how to convert `input_ids` indices into associated vectors
than the model's internal embedding lookup matrix.
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)
causal_attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Causal mask for the text model. 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)
"""
hidden_states = inputs_embeds
for idx, encoder_layer in enumerate(self.layers):
hidden_states = encoder_layer(
hidden_states,
attention_mask,
causal_attention_mask,
)
return hidden_states
class CLIPTextTransformer(nn.Module):
def __init__(self, config: CLIPTextConfig):
super().__init__()
self.config = config
embed_dim = config.hidden_size
self.embeddings = CLIPTextEmbeddings(config)
self.encoder = CLIPEncoder(
prefix=f"{prefix}.encoder", config=config, weights=weights
)
self.final_layer_norm = nn.LayerNorm(embed_dim, eps=config.layer_norm_eps)
# For `pooled_output` computation
self.eos_token_id = config.eos_token_id
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
):
r"""
Returns:
"""
if input_ids is None:
raise ValueError("You have to specify input_ids")
input_shape = input_ids.size()
input_ids = input_ids.view(-1, input_shape[-1])
hidden_states = self.embeddings(input_ids=input_ids, position_ids=position_ids)
# CLIP's text model uses causal mask, prepare it here.
# https://github.com/openai/CLIP/blob/cfcffb90e69f37bf2ff1e988237a0fbe41f33c04/clip/model.py#L324
causal_attention_mask = _create_4d_causal_attention_mask(
input_shape, hidden_states.dtype, device=hidden_states.device
)
# expand attention_mask
if attention_mask is not None:
# [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
attention_mask = _prepare_4d_attention_mask(
attention_mask, hidden_states.dtype
)
encoder_outputs = self.encoder(
inputs_embeds=hidden_states,
attention_mask=attention_mask,
causal_attention_mask=causal_attention_mask,
)
last_hidden_state = encoder_outputs[0]
last_hidden_state = self.final_layer_norm(last_hidden_state)
if self.eos_token_id == 2:
# The `eos_token_id` was incorrect before PR #24773: Let's keep what have been done here.
# A CLIP model with such `eos_token_id` in the config can't work correctly with extra new tokens added
# ------------------------------------------------------------
# text_embeds.shape = [batch_size, sequence_length, transformer.width]
# take features from the eot embedding (eot_token is the highest number in each sequence)
# casting to torch.int for onnx compatibility: argmax doesn't support int64 inputs with opset 14
pooled_output = last_hidden_state[
torch.arange(
last_hidden_state.shape[0], device=last_hidden_state.device
),
input_ids.to(dtype=torch.int, device=last_hidden_state.device).argmax(
dim=-1
),
]
else:
# The config gets updated `eos_token_id` from PR #24773 (so the use of exta new tokens is possible)
pooled_output = last_hidden_state[
torch.arange(
last_hidden_state.shape[0], device=last_hidden_state.device
),
# We need to get the first position of `eos_token_id` value (`pad_token_ids` might equal to `eos_token_id`)
(
input_ids.to(dtype=torch.int, device=last_hidden_state.device)
== self.eos_token_id
)
.int()
.argmax(dim=-1),
]
return last_hidden_state
class CLIPTextModel(CLIPPreTrainedModel):
config_class = CLIPTextConfig
_no_split_modules = ["CLIPTextEmbeddings", "CLIPEncoderLayer"]
def __init__(self, config: CLIPTextConfig):
super().__init__(config)
self.text_model = CLIPTextTransformer(config)
# Initialize weights and apply final processing
self.post_init()
def forward(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
):
r"""
Returns:
Examples:
```python
>>> from transformers import AutoTokenizer, CLIPTextModel
>>> model = CLIPTextModel.from_pretrained("openai/clip-vit-base-patch32")
>>> tokenizer = AutoTokenizer.from_pretrained("openai/clip-vit-base-patch32")
>>> inputs = tokenizer(["a photo of a cat", "a photo of a dog"], padding=True, return_tensors="pt")
>>> outputs = model(**inputs)
>>> last_hidden_state = outputs.last_hidden_state
>>> pooled_output = outputs.pooler_output # pooled (EOS token) states
```"""
return_dict = (
return_dict if return_dict is not None else self.config.use_return_dict
)
return self.text_model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
)
class CLIPVisionTransformer(nn.Module):
def __init__(self, prefix, config: CLIPVisionConfig, weights):
super().__init__()
self.config = config
embed_dim = config.hidden_size
self.embeddings = CLIPVisionEmbeddings(
prefix=f"{prefix}.embeddings", config=config, weights=weights
)
self.pre_layrnorm = nn.LayerNorm.load(
prefix=f"{prefix}.pre_layrnorm", weights=weights, eps=config.layer_norm_eps
)
self.encoder = CLIPEncoder(
prefix=f"{prefix}.encoder", config=config, weights=weights
)
# self.post_layernorm = nn.LayerNorm.load(prefix=f"{prefix}.post_layernorm", weights=weights, eps=config.layer_norm_eps)
def forward(
self,
pixel_values: Optional[torch.FloatTensor] = None,
):
r"""
Returns:
"""
if pixel_values is None:
raise ValueError("You have to specify pixel_values")
hidden_states = self.embeddings(pixel_values)
hidden_states = self.pre_layrnorm(hidden_states)
encoder_outputs = self.encoder(
inputs_embeds=hidden_states,
)
last_hidden_state = encoder_outputs
# pooled_output = last_hidden_state[:, 0, :]
# pooled_output = self.post_layernorm(pooled_output)
return BaseModelOutputWithPooling(
last_hidden_state=last_hidden_state,
# pooler_output=pooled_output,
# hidden_states=encoder_outputs,
)
class CLIPVisionModel(CLIPPreTrainedModel):
config_class = CLIPVisionConfig
main_input_name = "pixel_values"
_no_split_modules = ["CLIPEncoderLayer"]
def __init__(self, config: CLIPVisionConfig):
super().__init__(config)
self.vision_model = CLIPVisionTransformer(config)
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self) -> nn.Module:
return self.vision_model.embeddings.patch_embedding
def forward(
self,
pixel_values: Optional[torch.FloatTensor] = None,
):
r"""
Returns:
Examples:
```python
>>> from PIL import Image
>>> import requests
>>> from transformers import AutoProcessor, CLIPVisionModel
>>> model = CLIPVisionModel.from_pretrained("openai/clip-vit-base-patch32")
>>> processor = AutoProcessor.from_pretrained("openai/clip-vit-base-patch32")
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = processor(images=image, return_tensors="pt")
>>> outputs = model(**inputs)
>>> last_hidden_state = outputs.last_hidden_state
>>> pooled_output = outputs.pooler_output # pooled CLS states
```"""
return_dict = (
return_dict if return_dict is not None else self.config.use_return_dict
)
return self.vision_model(
pixel_values=pixel_values,
)
class CLIPModel(nn.Module):
def __init__(self, prefix, config: CLIPConfig, weights):
super().__init__()
text_config = config.text_config
vision_config = config.vision_config
self.projection_dim = config.projection_dim
self.text_embed_dim = text_config.hidden_size
self.vision_embed_dim = vision_config.hidden_size
self.text_model = CLIPTextTransformer(text_config)
self.vision_model = CLIPVisionTransformer(vision_config)
self.visual_projection = nn.Linear(
self.vision_embed_dim, self.projection_dim, bias=False
)
self.text_projection = nn.Linear(
self.text_embed_dim, self.projection_dim, bias=False
)
self.logit_scale = nn.Parameter(
torch.tensor(self.config.logit_scale_init_value)
)
# Initialize weights and apply final processing
self.post_init()
def get_text_features(
self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.Tensor] = None,
) -> torch.FloatTensor:
r"""
Returns:
text_features (`torch.FloatTensor` of shape `(batch_size, output_dim`): The text embeddings obtained by
applying the projection layer to the pooled output of [`CLIPTextModel`].
Examples:
```python
>>> from transformers import AutoTokenizer, CLIPModel
>>> model = CLIPModel.from_pretrained("openai/clip-vit-base-patch32")
>>> tokenizer = AutoTokenizer.from_pretrained("openai/clip-vit-base-patch32")
>>> inputs = tokenizer(["a photo of a cat", "a photo of a dog"], padding=True, return_tensors="pt")
>>> text_features = model.get_text_features(**inputs)
```"""
text_outputs = self.text_model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
)
pooled_output = text_outputs[1]
text_features = self.text_projection(pooled_output)
return text_features
def get_image_features(
self,
pixel_values: Optional[torch.FloatTensor] = None,
) -> torch.FloatTensor:
r"""
Returns:
image_features (`torch.FloatTensor` of shape `(batch_size, output_dim`): The image embeddings obtained by
applying the projection layer to the pooled output of [`CLIPVisionModel`].
Examples:
```python
>>> from PIL import Image
>>> import requests
>>> from transformers import AutoProcessor, CLIPModel
>>> model = CLIPModel.from_pretrained("openai/clip-vit-base-patch32")
>>> processor = AutoProcessor.from_pretrained("openai/clip-vit-base-patch32")
>>> 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_features = model.get_image_features(**inputs)
```"""
# Use CLIP model's config for some fields (if specified) instead of those of vision & text components.
vision_outputs = self.vision_model(
pixel_values=pixel_values,
)
pooled_output = vision_outputs[1] # pooled_output
image_features = self.visual_projection(pooled_output)
return image_features
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
pixel_values: Optional[torch.FloatTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
position_ids: Optional[torch.LongTensor] = None,
):
r"""
Returns:
Examples:
```python
>>> from PIL import Image
>>> import requests
>>> from transformers import AutoProcessor, CLIPModel
>>> model = CLIPModel.from_pretrained("openai/clip-vit-base-patch32")
>>> processor = AutoProcessor.from_pretrained("openai/clip-vit-base-patch32")
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> inputs = processor(
... text=["a photo of a cat", "a photo of a dog"], images=image, return_tensors="pt", padding=True
... )
>>> outputs = model(**inputs)
>>> logits_per_image = outputs.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
```"""
# Use CLIP model's config for some fields (if specified) instead of those of vision & text components.
vision_outputs = self.vision_model(
pixel_values=pixel_values,
return_dict=return_dict,
)
text_outputs = self.text_model(
input_ids=input_ids,
attention_mask=attention_mask,
position_ids=position_ids,
return_dict=return_dict,
)
image_embeds = vision_outputs[1]
image_embeds = self.visual_projection(image_embeds)
text_embeds = text_outputs[1]
text_embeds = self.text_projection(text_embeds)
# normalized features
image_embeds = image_embeds / image_embeds.norm(p=2, dim=-1, keepdim=True)
text_embeds = text_embeds / text_embeds.norm(p=2, dim=-1, keepdim=True)
# cosine similarity as logits
logit_scale = self.logit_scale.exp()
logits_per_text = torch.matmul(text_embeds, image_embeds.t()) * logit_scale
logits_per_image = logits_per_text.t()
return logits_per_image, logits_per_text