team-10/venv/Lib/site-packages/transformers/models/detr/modeling_detr.py
2025-08-02 02:00:33 +02:00

1692 lines
76 KiB
Python

# coding=utf-8
# Copyright 2021 Facebook AI Research The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""PyTorch DETR model."""
import math
from dataclasses import dataclass
from typing import Optional, Union
import torch
from torch import Tensor, nn
from ...activations import ACT2FN
from ...modeling_attn_mask_utils import _prepare_4d_attention_mask
from ...modeling_layers import GradientCheckpointingLayer
from ...modeling_outputs import BaseModelOutput, BaseModelOutputWithCrossAttentions, Seq2SeqModelOutput
from ...modeling_utils import PreTrainedModel
from ...utils import (
ModelOutput,
auto_docstring,
is_timm_available,
logging,
requires_backends,
)
from ...utils.backbone_utils import load_backbone
from .configuration_detr import DetrConfig
if is_timm_available():
from timm import create_model
logger = logging.get_logger(__name__)
@dataclass
@auto_docstring(
custom_intro="""
Base class for outputs of the DETR decoder. This class adds one attribute to BaseModelOutputWithCrossAttentions,
namely an optional stack of intermediate decoder activations, i.e. the output of each decoder layer, each of them
gone through a layernorm. This is useful when training the model with auxiliary decoding losses.
"""
)
class DetrDecoderOutput(BaseModelOutputWithCrossAttentions):
r"""
cross_attentions (`tuple(torch.FloatTensor)`, *optional*, returned when `output_attentions=True` and `config.add_cross_attention=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 of the decoder's cross-attention layer, after the attention softmax,
used to compute the weighted average in the cross-attention heads.
intermediate_hidden_states (`torch.FloatTensor` of shape `(config.decoder_layers, batch_size, num_queries, hidden_size)`, *optional*, returned when `config.auxiliary_loss=True`):
Intermediate decoder activations, i.e. the output of each decoder layer, each of them gone through a
layernorm.
"""
intermediate_hidden_states: Optional[torch.FloatTensor] = None
@dataclass
@auto_docstring(
custom_intro="""
Base class for outputs of the DETR encoder-decoder model. This class adds one attribute to Seq2SeqModelOutput,
namely an optional stack of intermediate decoder activations, i.e. the output of each decoder layer, each of them
gone through a layernorm. This is useful when training the model with auxiliary decoding losses.
"""
)
class DetrModelOutput(Seq2SeqModelOutput):
r"""
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 decoder of the model.
intermediate_hidden_states (`torch.FloatTensor` of shape `(config.decoder_layers, batch_size, sequence_length, hidden_size)`, *optional*, returned when `config.auxiliary_loss=True`):
Intermediate decoder activations, i.e. the output of each decoder layer, each of them gone through a
layernorm.
"""
intermediate_hidden_states: Optional[torch.FloatTensor] = None
@dataclass
@auto_docstring(
custom_intro="""
Output type of [`DetrForObjectDetection`].
"""
)
class DetrObjectDetectionOutput(ModelOutput):
r"""
loss (`torch.FloatTensor` of shape `(1,)`, *optional*, returned when `labels` are provided)):
Total loss as a linear combination of a negative log-likehood (cross-entropy) for class prediction and a
bounding box loss. The latter is defined as a linear combination of the L1 loss and the generalized
scale-invariant IoU loss.
loss_dict (`Dict`, *optional*):
A dictionary containing the individual losses. Useful for logging.
logits (`torch.FloatTensor` of shape `(batch_size, num_queries, num_classes + 1)`):
Classification logits (including no-object) for all queries.
pred_boxes (`torch.FloatTensor` of shape `(batch_size, num_queries, 4)`):
Normalized boxes coordinates for all queries, represented as (center_x, center_y, width, height). These
values are normalized in [0, 1], relative to the size of each individual image in the batch (disregarding
possible padding). You can use [`~DetrImageProcessor.post_process_object_detection`] to retrieve the
unnormalized bounding boxes.
auxiliary_outputs (`list[Dict]`, *optional*):
Optional, only returned when auxiliary losses are activated (i.e. `config.auxiliary_loss` is set to `True`)
and labels are provided. It is a list of dictionaries containing the two above keys (`logits` and
`pred_boxes`) for each decoder layer.
last_hidden_state (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Sequence of hidden-states at the output of the last layer of the decoder of the model.
"""
loss: Optional[torch.FloatTensor] = None
loss_dict: Optional[dict] = None
logits: Optional[torch.FloatTensor] = None
pred_boxes: Optional[torch.FloatTensor] = None
auxiliary_outputs: Optional[list[dict]] = None
last_hidden_state: Optional[torch.FloatTensor] = None
decoder_hidden_states: Optional[tuple[torch.FloatTensor]] = None
decoder_attentions: Optional[tuple[torch.FloatTensor]] = None
cross_attentions: Optional[tuple[torch.FloatTensor]] = None
encoder_last_hidden_state: Optional[torch.FloatTensor] = None
encoder_hidden_states: Optional[tuple[torch.FloatTensor]] = None
encoder_attentions: Optional[tuple[torch.FloatTensor]] = None
@dataclass
@auto_docstring(
custom_intro="""
Output type of [`DetrForSegmentation`].
"""
)
class DetrSegmentationOutput(ModelOutput):
r"""
loss (`torch.FloatTensor` of shape `(1,)`, *optional*, returned when `labels` are provided)):
Total loss as a linear combination of a negative log-likehood (cross-entropy) for class prediction and a
bounding box loss. The latter is defined as a linear combination of the L1 loss and the generalized
scale-invariant IoU loss.
loss_dict (`Dict`, *optional*):
A dictionary containing the individual losses. Useful for logging.
logits (`torch.FloatTensor` of shape `(batch_size, num_queries, num_classes + 1)`):
Classification logits (including no-object) for all queries.
pred_boxes (`torch.FloatTensor` of shape `(batch_size, num_queries, 4)`):
Normalized boxes coordinates for all queries, represented as (center_x, center_y, width, height). These
values are normalized in [0, 1], relative to the size of each individual image in the batch (disregarding
possible padding). You can use [`~DetrImageProcessor.post_process_object_detection`] to retrieve the
unnormalized bounding boxes.
pred_masks (`torch.FloatTensor` of shape `(batch_size, num_queries, height/4, width/4)`):
Segmentation masks logits for all queries. See also
[`~DetrImageProcessor.post_process_semantic_segmentation`] or
[`~DetrImageProcessor.post_process_instance_segmentation`]
[`~DetrImageProcessor.post_process_panoptic_segmentation`] to evaluate semantic, instance and panoptic
segmentation masks respectively.
auxiliary_outputs (`list[Dict]`, *optional*):
Optional, only returned when auxiliary losses are activated (i.e. `config.auxiliary_loss` is set to `True`)
and labels are provided. It is a list of dictionaries containing the two above keys (`logits` and
`pred_boxes`) for each decoder layer.
last_hidden_state (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Sequence of hidden-states at the output of the last layer of the decoder of the model.
"""
loss: Optional[torch.FloatTensor] = None
loss_dict: Optional[dict] = None
logits: Optional[torch.FloatTensor] = None
pred_boxes: Optional[torch.FloatTensor] = None
pred_masks: Optional[torch.FloatTensor] = None
auxiliary_outputs: Optional[list[dict]] = None
last_hidden_state: Optional[torch.FloatTensor] = None
decoder_hidden_states: Optional[tuple[torch.FloatTensor]] = None
decoder_attentions: Optional[tuple[torch.FloatTensor]] = None
cross_attentions: Optional[tuple[torch.FloatTensor]] = None
encoder_last_hidden_state: Optional[torch.FloatTensor] = None
encoder_hidden_states: Optional[tuple[torch.FloatTensor]] = None
encoder_attentions: Optional[tuple[torch.FloatTensor]] = None
# BELOW: utilities copied from
# https://github.com/facebookresearch/detr/blob/master/backbone.py
class DetrFrozenBatchNorm2d(nn.Module):
"""
BatchNorm2d where the batch statistics and the affine parameters are fixed.
Copy-paste from torchvision.misc.ops with added eps before rqsrt, without which any other models than
torchvision.models.resnet[18,34,50,101] produce nans.
"""
def __init__(self, n):
super().__init__()
self.register_buffer("weight", torch.ones(n))
self.register_buffer("bias", torch.zeros(n))
self.register_buffer("running_mean", torch.zeros(n))
self.register_buffer("running_var", torch.ones(n))
def _load_from_state_dict(
self, state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs
):
num_batches_tracked_key = prefix + "num_batches_tracked"
if num_batches_tracked_key in state_dict:
del state_dict[num_batches_tracked_key]
super()._load_from_state_dict(
state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs
)
def forward(self, x):
# move reshapes to the beginning
# to make it user-friendly
weight = self.weight.reshape(1, -1, 1, 1)
bias = self.bias.reshape(1, -1, 1, 1)
running_var = self.running_var.reshape(1, -1, 1, 1)
running_mean = self.running_mean.reshape(1, -1, 1, 1)
epsilon = 1e-5
scale = weight * (running_var + epsilon).rsqrt()
bias = bias - running_mean * scale
return x * scale + bias
def replace_batch_norm(model):
r"""
Recursively replace all `torch.nn.BatchNorm2d` with `DetrFrozenBatchNorm2d`.
Args:
model (torch.nn.Module):
input model
"""
for name, module in model.named_children():
if isinstance(module, nn.BatchNorm2d):
new_module = DetrFrozenBatchNorm2d(module.num_features)
if not module.weight.device == torch.device("meta"):
new_module.weight.data.copy_(module.weight)
new_module.bias.data.copy_(module.bias)
new_module.running_mean.data.copy_(module.running_mean)
new_module.running_var.data.copy_(module.running_var)
model._modules[name] = new_module
if len(list(module.children())) > 0:
replace_batch_norm(module)
class DetrConvEncoder(nn.Module):
"""
Convolutional backbone, using either the AutoBackbone API or one from the timm library.
nn.BatchNorm2d layers are replaced by DetrFrozenBatchNorm2d as defined above.
"""
def __init__(self, config):
super().__init__()
self.config = config
# For backwards compatibility we have to use the timm library directly instead of the AutoBackbone API
if config.use_timm_backbone:
# We default to values which were previously hard-coded. This enables configurability from the config
# using backbone arguments, while keeping the default behavior the same.
requires_backends(self, ["timm"])
kwargs = getattr(config, "backbone_kwargs", {})
kwargs = {} if kwargs is None else kwargs.copy()
out_indices = kwargs.pop("out_indices", (1, 2, 3, 4))
num_channels = kwargs.pop("in_chans", config.num_channels)
if config.dilation:
kwargs["output_stride"] = kwargs.get("output_stride", 16)
backbone = create_model(
config.backbone,
pretrained=config.use_pretrained_backbone,
features_only=True,
out_indices=out_indices,
in_chans=num_channels,
**kwargs,
)
else:
backbone = load_backbone(config)
# replace batch norm by frozen batch norm
with torch.no_grad():
replace_batch_norm(backbone)
self.model = backbone
self.intermediate_channel_sizes = (
self.model.feature_info.channels() if config.use_timm_backbone else self.model.channels
)
backbone_model_type = None
if config.backbone is not None:
backbone_model_type = config.backbone
elif config.backbone_config is not None:
backbone_model_type = config.backbone_config.model_type
else:
raise ValueError("Either `backbone` or `backbone_config` should be provided in the config")
if "resnet" in backbone_model_type:
for name, parameter in self.model.named_parameters():
if config.use_timm_backbone:
if "layer2" not in name and "layer3" not in name and "layer4" not in name:
parameter.requires_grad_(False)
else:
if "stage.1" not in name and "stage.2" not in name and "stage.3" not in name:
parameter.requires_grad_(False)
def forward(self, pixel_values: torch.Tensor, pixel_mask: torch.Tensor):
# send pixel_values through the model to get list of feature maps
features = self.model(pixel_values) if self.config.use_timm_backbone else self.model(pixel_values).feature_maps
out = []
for feature_map in features:
# downsample pixel_mask to match shape of corresponding feature_map
mask = nn.functional.interpolate(pixel_mask[None].float(), size=feature_map.shape[-2:]).to(torch.bool)[0]
out.append((feature_map, mask))
return out
class DetrConvModel(nn.Module):
"""
This module adds 2D position embeddings to all intermediate feature maps of the convolutional encoder.
"""
def __init__(self, conv_encoder, position_embedding):
super().__init__()
self.conv_encoder = conv_encoder
self.position_embedding = position_embedding
def forward(self, pixel_values, pixel_mask):
# send pixel_values and pixel_mask through backbone to get list of (feature_map, pixel_mask) tuples
out = self.conv_encoder(pixel_values, pixel_mask)
pos = []
for feature_map, mask in out:
# position encoding
pos.append(self.position_embedding(feature_map, mask).to(feature_map.dtype))
return out, pos
class DetrSinePositionEmbedding(nn.Module):
"""
This is a more standard version of the position embedding, very similar to the one used by the Attention is all you
need paper, generalized to work on images.
"""
def __init__(self, embedding_dim=64, temperature=10000, normalize=False, scale=None):
super().__init__()
self.embedding_dim = embedding_dim
self.temperature = temperature
self.normalize = normalize
if scale is not None and normalize is False:
raise ValueError("normalize should be True if scale is passed")
if scale is None:
scale = 2 * math.pi
self.scale = scale
def forward(self, pixel_values, pixel_mask):
if pixel_mask is None:
raise ValueError("No pixel mask provided")
y_embed = pixel_mask.cumsum(1, dtype=torch.float32)
x_embed = pixel_mask.cumsum(2, dtype=torch.float32)
if self.normalize:
y_embed = y_embed / (y_embed[:, -1:, :] + 1e-6) * self.scale
x_embed = x_embed / (x_embed[:, :, -1:] + 1e-6) * self.scale
dim_t = torch.arange(self.embedding_dim, dtype=torch.int64, device=pixel_values.device).float()
dim_t = self.temperature ** (2 * torch.div(dim_t, 2, rounding_mode="floor") / self.embedding_dim)
pos_x = x_embed[:, :, :, None] / dim_t
pos_y = y_embed[:, :, :, None] / dim_t
pos_x = torch.stack((pos_x[:, :, :, 0::2].sin(), pos_x[:, :, :, 1::2].cos()), dim=4).flatten(3)
pos_y = torch.stack((pos_y[:, :, :, 0::2].sin(), pos_y[:, :, :, 1::2].cos()), dim=4).flatten(3)
pos = torch.cat((pos_y, pos_x), dim=3).permute(0, 3, 1, 2)
return pos
class DetrLearnedPositionEmbedding(nn.Module):
"""
This module learns positional embeddings up to a fixed maximum size.
"""
def __init__(self, embedding_dim=256):
super().__init__()
self.row_embeddings = nn.Embedding(50, embedding_dim)
self.column_embeddings = nn.Embedding(50, embedding_dim)
def forward(self, pixel_values, pixel_mask=None):
height, width = pixel_values.shape[-2:]
width_values = torch.arange(width, device=pixel_values.device)
height_values = torch.arange(height, device=pixel_values.device)
x_emb = self.column_embeddings(width_values)
y_emb = self.row_embeddings(height_values)
pos = torch.cat([x_emb.unsqueeze(0).repeat(height, 1, 1), y_emb.unsqueeze(1).repeat(1, width, 1)], dim=-1)
pos = pos.permute(2, 0, 1)
pos = pos.unsqueeze(0)
pos = pos.repeat(pixel_values.shape[0], 1, 1, 1)
return pos
def build_position_encoding(config):
n_steps = config.d_model // 2
if config.position_embedding_type == "sine":
# TODO find a better way of exposing other arguments
position_embedding = DetrSinePositionEmbedding(n_steps, normalize=True)
elif config.position_embedding_type == "learned":
position_embedding = DetrLearnedPositionEmbedding(n_steps)
else:
raise ValueError(f"Not supported {config.position_embedding_type}")
return position_embedding
class DetrAttention(nn.Module):
"""
Multi-headed attention from 'Attention Is All You Need' paper.
Here, we add position embeddings to the queries and keys (as explained in the DETR paper).
"""
def __init__(
self,
embed_dim: int,
num_heads: int,
dropout: float = 0.0,
bias: bool = True,
):
super().__init__()
self.embed_dim = embed_dim
self.num_heads = num_heads
self.dropout = dropout
self.head_dim = embed_dim // num_heads
if self.head_dim * 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" {num_heads})."
)
self.scaling = self.head_dim**-0.5
self.k_proj = nn.Linear(embed_dim, embed_dim, bias=bias)
self.v_proj = nn.Linear(embed_dim, embed_dim, bias=bias)
self.q_proj = nn.Linear(embed_dim, embed_dim, bias=bias)
self.out_proj = nn.Linear(embed_dim, embed_dim, bias=bias)
def _shape(self, tensor: torch.Tensor, seq_len: int, batch_size: int):
return tensor.view(batch_size, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
def with_pos_embed(self, tensor: torch.Tensor, object_queries: Optional[Tensor]):
return tensor if object_queries is None else tensor + object_queries
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
object_queries: Optional[torch.Tensor] = None,
key_value_states: Optional[torch.Tensor] = None,
spatial_position_embeddings: Optional[torch.Tensor] = None,
output_attentions: bool = False,
) -> tuple[torch.Tensor, Optional[torch.Tensor], Optional[tuple[torch.Tensor]]]:
"""Input shape: Batch x Time x Channel"""
# if key_value_states are provided this layer is used as a cross-attention layer
# for the decoder
is_cross_attention = key_value_states is not None
batch_size, target_len, embed_dim = hidden_states.size()
# add position embeddings to the hidden states before projecting to queries and keys
if object_queries is not None:
hidden_states_original = hidden_states
hidden_states = self.with_pos_embed(hidden_states, object_queries)
# add key-value position embeddings to the key value states
if spatial_position_embeddings is not None:
key_value_states_original = key_value_states
key_value_states = self.with_pos_embed(key_value_states, spatial_position_embeddings)
# get query proj
query_states = self.q_proj(hidden_states) * self.scaling
# get key, value proj
if is_cross_attention:
# cross_attentions
key_states = self._shape(self.k_proj(key_value_states), -1, batch_size)
value_states = self._shape(self.v_proj(key_value_states_original), -1, batch_size)
else:
# self_attention
key_states = self._shape(self.k_proj(hidden_states), -1, batch_size)
value_states = self._shape(self.v_proj(hidden_states_original), -1, batch_size)
proj_shape = (batch_size * self.num_heads, -1, self.head_dim)
query_states = self._shape(query_states, target_len, batch_size).view(*proj_shape)
key_states = key_states.view(*proj_shape)
value_states = value_states.view(*proj_shape)
source_len = key_states.size(1)
attn_weights = torch.bmm(query_states, key_states.transpose(1, 2))
if attn_weights.size() != (batch_size * self.num_heads, target_len, source_len):
raise ValueError(
f"Attention weights should be of size {(batch_size * self.num_heads, target_len, source_len)}, but is"
f" {attn_weights.size()}"
)
if attention_mask is not None:
if attention_mask.size() != (batch_size, 1, target_len, source_len):
raise ValueError(
f"Attention mask should be of size {(batch_size, 1, target_len, source_len)}, but is"
f" {attention_mask.size()}"
)
attn_weights = attn_weights.view(batch_size, self.num_heads, target_len, source_len) + attention_mask
attn_weights = attn_weights.view(batch_size * self.num_heads, target_len, source_len)
attn_weights = nn.functional.softmax(attn_weights, dim=-1)
if output_attentions:
# this operation is a bit awkward, but it's required to
# make sure that attn_weights keeps its gradient.
# In order to do so, attn_weights have to reshaped
# twice and have to be reused in the following
attn_weights_reshaped = attn_weights.view(batch_size, self.num_heads, target_len, source_len)
attn_weights = attn_weights_reshaped.view(batch_size * self.num_heads, target_len, source_len)
else:
attn_weights_reshaped = None
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() != (batch_size * self.num_heads, target_len, self.head_dim):
raise ValueError(
f"`attn_output` should be of size {(batch_size, self.num_heads, target_len, self.head_dim)}, but is"
f" {attn_output.size()}"
)
attn_output = attn_output.view(batch_size, self.num_heads, target_len, self.head_dim)
attn_output = attn_output.transpose(1, 2)
attn_output = attn_output.reshape(batch_size, target_len, embed_dim)
attn_output = self.out_proj(attn_output)
return attn_output, attn_weights_reshaped
class DetrEncoderLayer(nn.Module):
def __init__(self, config: DetrConfig):
super().__init__()
self.embed_dim = config.d_model
self.self_attn = DetrAttention(
embed_dim=self.embed_dim,
num_heads=config.encoder_attention_heads,
dropout=config.attention_dropout,
)
self.self_attn_layer_norm = nn.LayerNorm(self.embed_dim)
self.dropout = config.dropout
self.activation_fn = ACT2FN[config.activation_function]
self.activation_dropout = config.activation_dropout
self.fc1 = nn.Linear(self.embed_dim, config.encoder_ffn_dim)
self.fc2 = nn.Linear(config.encoder_ffn_dim, self.embed_dim)
self.final_layer_norm = nn.LayerNorm(self.embed_dim)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: torch.Tensor,
object_queries: Optional[torch.Tensor] = None,
output_attentions: bool = False,
):
"""
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, target_len, source_len)` where padding elements are indicated by very large negative
values.
object_queries (`torch.FloatTensor`, *optional*):
Object queries (also called content embeddings), to be added to the hidden states.
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, attn_weights = self.self_attn(
hidden_states=hidden_states,
attention_mask=attention_mask,
object_queries=object_queries,
output_attentions=output_attentions,
)
hidden_states = nn.functional.dropout(hidden_states, p=self.dropout, training=self.training)
hidden_states = residual + hidden_states
hidden_states = self.self_attn_layer_norm(hidden_states)
residual = hidden_states
hidden_states = self.activation_fn(self.fc1(hidden_states))
hidden_states = nn.functional.dropout(hidden_states, p=self.activation_dropout, training=self.training)
hidden_states = self.fc2(hidden_states)
hidden_states = nn.functional.dropout(hidden_states, p=self.dropout, training=self.training)
hidden_states = residual + hidden_states
hidden_states = self.final_layer_norm(hidden_states)
if self.training:
if torch.isinf(hidden_states).any() or torch.isnan(hidden_states).any():
clamp_value = torch.finfo(hidden_states.dtype).max - 1000
hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value)
outputs = (hidden_states,)
if output_attentions:
outputs += (attn_weights,)
return outputs
class DetrDecoderLayer(GradientCheckpointingLayer):
def __init__(self, config: DetrConfig):
super().__init__()
self.embed_dim = config.d_model
self.self_attn = DetrAttention(
embed_dim=self.embed_dim,
num_heads=config.decoder_attention_heads,
dropout=config.attention_dropout,
)
self.dropout = config.dropout
self.activation_fn = ACT2FN[config.activation_function]
self.activation_dropout = config.activation_dropout
self.self_attn_layer_norm = nn.LayerNorm(self.embed_dim)
self.encoder_attn = DetrAttention(
self.embed_dim,
config.decoder_attention_heads,
dropout=config.attention_dropout,
)
self.encoder_attn_layer_norm = nn.LayerNorm(self.embed_dim)
self.fc1 = nn.Linear(self.embed_dim, config.decoder_ffn_dim)
self.fc2 = nn.Linear(config.decoder_ffn_dim, self.embed_dim)
self.final_layer_norm = nn.LayerNorm(self.embed_dim)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
object_queries: Optional[torch.Tensor] = None,
query_position_embeddings: Optional[torch.Tensor] = None,
encoder_hidden_states: Optional[torch.Tensor] = None,
encoder_attention_mask: Optional[torch.Tensor] = None,
output_attentions: Optional[bool] = False,
):
"""
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, target_len, source_len)` where padding elements are indicated by very large negative
values.
object_queries (`torch.FloatTensor`, *optional*):
object_queries that are added to the hidden states
in the cross-attention layer.
query_position_embeddings (`torch.FloatTensor`, *optional*):
position embeddings that are added to the queries and keys
in the self-attention layer.
encoder_hidden_states (`torch.FloatTensor`):
cross attention input to the layer of shape `(batch, seq_len, embed_dim)`
encoder_attention_mask (`torch.FloatTensor`): encoder attention mask of size
`(batch, 1, target_len, source_len)` where padding elements are indicated by very large negative
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.
"""
residual = hidden_states
# Self Attention
hidden_states, self_attn_weights = self.self_attn(
hidden_states=hidden_states,
object_queries=query_position_embeddings,
attention_mask=attention_mask,
output_attentions=output_attentions,
)
hidden_states = nn.functional.dropout(hidden_states, p=self.dropout, training=self.training)
hidden_states = residual + hidden_states
hidden_states = self.self_attn_layer_norm(hidden_states)
# Cross-Attention Block
cross_attn_weights = None
if encoder_hidden_states is not None:
residual = hidden_states
hidden_states, cross_attn_weights = self.encoder_attn(
hidden_states=hidden_states,
object_queries=query_position_embeddings,
key_value_states=encoder_hidden_states,
attention_mask=encoder_attention_mask,
spatial_position_embeddings=object_queries,
output_attentions=output_attentions,
)
hidden_states = nn.functional.dropout(hidden_states, p=self.dropout, training=self.training)
hidden_states = residual + hidden_states
hidden_states = self.encoder_attn_layer_norm(hidden_states)
# Fully Connected
residual = hidden_states
hidden_states = self.activation_fn(self.fc1(hidden_states))
hidden_states = nn.functional.dropout(hidden_states, p=self.activation_dropout, training=self.training)
hidden_states = self.fc2(hidden_states)
hidden_states = nn.functional.dropout(hidden_states, p=self.dropout, training=self.training)
hidden_states = residual + hidden_states
hidden_states = self.final_layer_norm(hidden_states)
outputs = (hidden_states,)
if output_attentions:
outputs += (self_attn_weights, cross_attn_weights)
return outputs
@auto_docstring
class DetrPreTrainedModel(PreTrainedModel):
config: DetrConfig
base_model_prefix = "model"
main_input_name = "pixel_values"
_no_split_modules = [r"DetrConvEncoder", r"DetrEncoderLayer", r"DetrDecoderLayer"]
def _init_weights(self, module):
std = self.config.init_std
xavier_std = self.config.init_xavier_std
if isinstance(module, DetrMHAttentionMap):
nn.init.zeros_(module.k_linear.bias)
nn.init.zeros_(module.q_linear.bias)
nn.init.xavier_uniform_(module.k_linear.weight, gain=xavier_std)
nn.init.xavier_uniform_(module.q_linear.weight, gain=xavier_std)
elif isinstance(module, DetrLearnedPositionEmbedding):
nn.init.uniform_(module.row_embeddings.weight)
nn.init.uniform_(module.column_embeddings.weight)
if isinstance(module, (nn.Linear, nn.Conv2d, nn.BatchNorm2d)):
# Slightly different from the TF version which uses truncated_normal for initialization
# cf https://github.com/pytorch/pytorch/pull/5617
module.weight.data.normal_(mean=0.0, std=std)
if module.bias is not None:
module.bias.data.zero_()
elif isinstance(module, nn.Embedding):
module.weight.data.normal_(mean=0.0, std=std)
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
class DetrEncoder(DetrPreTrainedModel):
"""
Transformer encoder consisting of *config.encoder_layers* self attention layers. Each layer is a
[`DetrEncoderLayer`].
The encoder updates the flattened feature map through multiple self-attention layers.
Small tweak for DETR:
- object_queries are added to the forward pass.
Args:
config: DetrConfig
"""
def __init__(self, config: DetrConfig):
super().__init__(config)
self.dropout = config.dropout
self.layerdrop = config.encoder_layerdrop
self.layers = nn.ModuleList([DetrEncoderLayer(config) for _ in range(config.encoder_layers)])
# in the original DETR, no layernorm is used at the end of the encoder, as "normalize_before" is set to False by default
# Initialize weights and apply final processing
self.post_init()
def forward(
self,
inputs_embeds=None,
attention_mask=None,
object_queries=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
):
r"""
Args:
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`):
Flattened feature map (output of the backbone + projection layer) that is passed to the encoder.
attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on padding pixel features. Mask values selected in `[0, 1]`:
- 1 for pixel features that are real (i.e. **not masked**),
- 0 for pixel features that are padding (i.e. **masked**).
[What are attention masks?](../glossary#attention-mask)
object_queries (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`):
Object queries that are added to the queries in each self-attention layer.
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
hidden_states = inputs_embeds
hidden_states = nn.functional.dropout(hidden_states, p=self.dropout, training=self.training)
# expand attention_mask
if attention_mask is not None:
# [batch_size, seq_len] -> [batch_size, 1, target_seq_len, source_seq_len]
attention_mask = _prepare_4d_attention_mask(attention_mask, inputs_embeds.dtype)
encoder_states = () if output_hidden_states else None
all_attentions = () if output_attentions else None
for i, encoder_layer in enumerate(self.layers):
if output_hidden_states:
encoder_states = encoder_states + (hidden_states,)
# add LayerDrop (see https://huggingface.co/papers/1909.11556 for description)
to_drop = False
if self.training:
dropout_probability = torch.rand([])
if dropout_probability < self.layerdrop: # skip the layer
to_drop = True
if to_drop:
layer_outputs = (None, None)
else:
# we add object_queries as extra input to the encoder_layer
layer_outputs = encoder_layer(
hidden_states,
attention_mask,
object_queries=object_queries,
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
)
class DetrDecoder(DetrPreTrainedModel):
"""
Transformer decoder consisting of *config.decoder_layers* layers. Each layer is a [`DetrDecoderLayer`].
The decoder updates the query embeddings through multiple self-attention and cross-attention layers.
Some small tweaks for DETR:
- object_queries and query_position_embeddings are added to the forward pass.
- if self.config.auxiliary_loss is set to True, also returns a stack of activations from all decoding layers.
Args:
config: DetrConfig
"""
def __init__(self, config: DetrConfig):
super().__init__(config)
self.dropout = config.dropout
self.layerdrop = config.decoder_layerdrop
self.layers = nn.ModuleList([DetrDecoderLayer(config) for _ in range(config.decoder_layers)])
# in DETR, the decoder uses layernorm after the last decoder layer output
self.layernorm = nn.LayerNorm(config.d_model)
self.gradient_checkpointing = False
# Initialize weights and apply final processing
self.post_init()
def forward(
self,
inputs_embeds=None,
attention_mask=None,
encoder_hidden_states=None,
encoder_attention_mask=None,
object_queries=None,
query_position_embeddings=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
):
r"""
Args:
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`):
The query embeddings that are passed into the decoder.
attention_mask (`torch.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Mask to avoid performing attention on certain queries. Mask values selected in `[0, 1]`:
- 1 for queries that are **not masked**,
- 0 for queries that are **masked**.
[What are attention masks?](../glossary#attention-mask)
encoder_hidden_states (`torch.FloatTensor` of shape `(batch_size, encoder_sequence_length, hidden_size)`, *optional*):
Sequence of hidden-states at the output of the last layer of the encoder. Used in the cross-attention
of the decoder.
encoder_attention_mask (`torch.LongTensor` of shape `(batch_size, encoder_sequence_length)`, *optional*):
Mask to avoid performing cross-attention on padding pixel_values of the encoder. Mask values selected
in `[0, 1]`:
- 1 for pixels that are real (i.e. **not masked**),
- 0 for pixels that are padding (i.e. **masked**).
object_queries (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Object queries that are added to the queries and keys in each cross-attention layer.
query_position_embeddings (`torch.FloatTensor` of shape `(batch_size, num_queries, hidden_size)`):
, *optional*): Position embeddings that are added to the values and keys in each self-attention layer.
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
if inputs_embeds is not None:
hidden_states = inputs_embeds
input_shape = inputs_embeds.size()[:-1]
combined_attention_mask = None
if attention_mask is not None and combined_attention_mask is not None:
# [batch_size, seq_len] -> [batch_size, 1, target_seq_len, source_seq_len]
combined_attention_mask = combined_attention_mask + _prepare_4d_attention_mask(
attention_mask, inputs_embeds.dtype, tgt_len=input_shape[-1]
)
# expand encoder attention mask
if encoder_hidden_states is not None and encoder_attention_mask is not None:
# [batch_size, seq_len] -> [batch_size, 1, target_seq_len, source_seq_len]
encoder_attention_mask = _prepare_4d_attention_mask(
encoder_attention_mask, inputs_embeds.dtype, tgt_len=input_shape[-1]
)
# optional intermediate hidden states
intermediate = () if self.config.auxiliary_loss else None
# decoder layers
all_hidden_states = () if output_hidden_states else None
all_self_attns = () if output_attentions else None
all_cross_attentions = () if (output_attentions and encoder_hidden_states is not None) else None
for idx, decoder_layer in enumerate(self.layers):
# add LayerDrop (see https://huggingface.co/papers/1909.11556 for description)
if output_hidden_states:
all_hidden_states += (hidden_states,)
if self.training:
dropout_probability = torch.rand([])
if dropout_probability < self.layerdrop:
continue
layer_outputs = decoder_layer(
hidden_states,
combined_attention_mask,
object_queries,
query_position_embeddings,
encoder_hidden_states, # as a positional argument for gradient checkpointing
encoder_attention_mask=encoder_attention_mask,
output_attentions=output_attentions,
)
hidden_states = layer_outputs[0]
if self.config.auxiliary_loss:
hidden_states = self.layernorm(hidden_states)
intermediate += (hidden_states,)
if output_attentions:
all_self_attns += (layer_outputs[1],)
if encoder_hidden_states is not None:
all_cross_attentions += (layer_outputs[2],)
# finally, apply layernorm
hidden_states = self.layernorm(hidden_states)
# add hidden states from the last decoder layer
if output_hidden_states:
all_hidden_states += (hidden_states,)
# stack intermediate decoder activations
if self.config.auxiliary_loss:
intermediate = torch.stack(intermediate)
if not return_dict:
return tuple(
v
for v in [hidden_states, all_hidden_states, all_self_attns, all_cross_attentions, intermediate]
if v is not None
)
return DetrDecoderOutput(
last_hidden_state=hidden_states,
hidden_states=all_hidden_states,
attentions=all_self_attns,
cross_attentions=all_cross_attentions,
intermediate_hidden_states=intermediate,
)
@auto_docstring(
custom_intro="""
The bare DETR Model (consisting of a backbone and encoder-decoder Transformer) outputting raw hidden-states without
any specific head on top.
"""
)
class DetrModel(DetrPreTrainedModel):
def __init__(self, config: DetrConfig):
super().__init__(config)
# Create backbone + positional encoding
backbone = DetrConvEncoder(config)
object_queries = build_position_encoding(config)
self.backbone = DetrConvModel(backbone, object_queries)
# Create projection layer
self.input_projection = nn.Conv2d(backbone.intermediate_channel_sizes[-1], config.d_model, kernel_size=1)
self.query_position_embeddings = nn.Embedding(config.num_queries, config.d_model)
self.encoder = DetrEncoder(config)
self.decoder = DetrDecoder(config)
# Initialize weights and apply final processing
self.post_init()
def get_encoder(self):
return self.encoder
def get_decoder(self):
return self.decoder
def freeze_backbone(self):
for name, param in self.backbone.conv_encoder.model.named_parameters():
param.requires_grad_(False)
def unfreeze_backbone(self):
for name, param in self.backbone.conv_encoder.model.named_parameters():
param.requires_grad_(True)
@auto_docstring
def forward(
self,
pixel_values: torch.FloatTensor,
pixel_mask: Optional[torch.LongTensor] = None,
decoder_attention_mask: Optional[torch.FloatTensor] = None,
encoder_outputs: Optional[torch.FloatTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
decoder_inputs_embeds: Optional[torch.FloatTensor] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[tuple[torch.FloatTensor], DetrModelOutput]:
r"""
decoder_attention_mask (`torch.FloatTensor` of shape `(batch_size, num_queries)`, *optional*):
Not used by default. Can be used to mask object queries.
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing the flattened feature map (output of the backbone + projection layer), you
can choose to directly pass a flattened representation of an image.
decoder_inputs_embeds (`torch.FloatTensor` of shape `(batch_size, num_queries, hidden_size)`, *optional*):
Optionally, instead of initializing the queries with a tensor of zeros, you can choose to directly pass an
embedded representation.
Examples:
```python
>>> from transformers import AutoImageProcessor, DetrModel
>>> from PIL import Image
>>> import requests
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> image_processor = AutoImageProcessor.from_pretrained("facebook/detr-resnet-50")
>>> model = DetrModel.from_pretrained("facebook/detr-resnet-50")
>>> # prepare image for the model
>>> inputs = image_processor(images=image, return_tensors="pt")
>>> # forward pass
>>> outputs = model(**inputs)
>>> # the last hidden states are the final query embeddings of the Transformer decoder
>>> # these are of shape (batch_size, num_queries, hidden_size)
>>> last_hidden_states = outputs.last_hidden_state
>>> list(last_hidden_states.shape)
[1, 100, 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
batch_size, num_channels, height, width = pixel_values.shape
device = pixel_values.device
if pixel_mask is None:
pixel_mask = torch.ones(((batch_size, height, width)), device=device)
# First, sent pixel_values + pixel_mask through Backbone to obtain the features
# pixel_values should be of shape (batch_size, num_channels, height, width)
# pixel_mask should be of shape (batch_size, height, width)
features, object_queries_list = self.backbone(pixel_values, pixel_mask)
# get final feature map and downsampled mask
feature_map, mask = features[-1]
if mask is None:
raise ValueError("Backbone does not return downsampled pixel mask")
# Second, apply 1x1 convolution to reduce the channel dimension to d_model (256 by default)
projected_feature_map = self.input_projection(feature_map)
# Third, flatten the feature map + position embeddings of shape NxCxHxW to NxCxHW, and permute it to NxHWxC
# In other words, turn their shape into (batch_size, sequence_length, hidden_size)
flattened_features = projected_feature_map.flatten(2).permute(0, 2, 1)
object_queries = object_queries_list[-1].flatten(2).permute(0, 2, 1)
flattened_mask = mask.flatten(1)
# Fourth, sent flattened_features + flattened_mask + position embeddings through encoder
# flattened_features is a Tensor of shape (batch_size, height*width, hidden_size)
# flattened_mask is a Tensor of shape (batch_size, height*width)
if encoder_outputs is None:
encoder_outputs = self.encoder(
inputs_embeds=flattened_features,
attention_mask=flattened_mask,
object_queries=object_queries,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
# If the user passed a tuple for encoder_outputs, we wrap it in a BaseModelOutput when return_dict=True
elif return_dict and not isinstance(encoder_outputs, BaseModelOutput):
encoder_outputs = BaseModelOutput(
last_hidden_state=encoder_outputs[0],
hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None,
attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None,
)
# Fifth, sent query embeddings + object_queries through the decoder (which is conditioned on the encoder output)
query_position_embeddings = self.query_position_embeddings.weight.unsqueeze(0).repeat(batch_size, 1, 1)
queries = torch.zeros_like(query_position_embeddings)
# decoder outputs consists of (dec_features, dec_hidden, dec_attn)
decoder_outputs = self.decoder(
inputs_embeds=queries,
attention_mask=None,
object_queries=object_queries,
query_position_embeddings=query_position_embeddings,
encoder_hidden_states=encoder_outputs[0],
encoder_attention_mask=flattened_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
if not return_dict:
return decoder_outputs + encoder_outputs
return DetrModelOutput(
last_hidden_state=decoder_outputs.last_hidden_state,
decoder_hidden_states=decoder_outputs.hidden_states,
decoder_attentions=decoder_outputs.attentions,
cross_attentions=decoder_outputs.cross_attentions,
encoder_last_hidden_state=encoder_outputs.last_hidden_state,
encoder_hidden_states=encoder_outputs.hidden_states,
encoder_attentions=encoder_outputs.attentions,
intermediate_hidden_states=decoder_outputs.intermediate_hidden_states,
)
# taken from https://github.com/facebookresearch/detr/blob/master/models/detr.py
class DetrMLPPredictionHead(nn.Module):
"""
Very simple multi-layer perceptron (MLP, also called FFN), used to predict the normalized center coordinates,
height and width of a bounding box w.r.t. an image.
Copied from https://github.com/facebookresearch/detr/blob/master/models/detr.py
"""
def __init__(self, input_dim, hidden_dim, output_dim, num_layers):
super().__init__()
self.num_layers = num_layers
h = [hidden_dim] * (num_layers - 1)
self.layers = nn.ModuleList(nn.Linear(n, k) for n, k in zip([input_dim] + h, h + [output_dim]))
def forward(self, x):
for i, layer in enumerate(self.layers):
x = nn.functional.relu(layer(x)) if i < self.num_layers - 1 else layer(x)
return x
@auto_docstring(
custom_intro="""
DETR Model (consisting of a backbone and encoder-decoder Transformer) with object detection heads on top, for tasks
such as COCO detection.
"""
)
class DetrForObjectDetection(DetrPreTrainedModel):
def __init__(self, config: DetrConfig):
super().__init__(config)
# DETR encoder-decoder model
self.model = DetrModel(config)
# Object detection heads
self.class_labels_classifier = nn.Linear(
config.d_model, config.num_labels + 1
) # We add one for the "no object" class
self.bbox_predictor = DetrMLPPredictionHead(
input_dim=config.d_model, hidden_dim=config.d_model, output_dim=4, num_layers=3
)
# Initialize weights and apply final processing
self.post_init()
@auto_docstring
def forward(
self,
pixel_values: torch.FloatTensor,
pixel_mask: Optional[torch.LongTensor] = None,
decoder_attention_mask: Optional[torch.FloatTensor] = None,
encoder_outputs: Optional[torch.FloatTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
decoder_inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[list[dict]] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[tuple[torch.FloatTensor], DetrObjectDetectionOutput]:
r"""
decoder_attention_mask (`torch.FloatTensor` of shape `(batch_size, num_queries)`, *optional*):
Not used by default. Can be used to mask object queries.
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing the flattened feature map (output of the backbone + projection layer), you
can choose to directly pass a flattened representation of an image.
decoder_inputs_embeds (`torch.FloatTensor` of shape `(batch_size, num_queries, hidden_size)`, *optional*):
Optionally, instead of initializing the queries with a tensor of zeros, you can choose to directly pass an
embedded representation.
labels (`list[Dict]` of len `(batch_size,)`, *optional*):
Labels for computing the bipartite matching loss. List of dicts, each dictionary containing at least the
following 2 keys: 'class_labels' and 'boxes' (the class labels and bounding boxes of an image in the batch
respectively). The class labels themselves should be a `torch.LongTensor` of len `(number of bounding boxes
in the image,)` and the boxes a `torch.FloatTensor` of shape `(number of bounding boxes in the image, 4)`.
Examples:
```python
>>> from transformers import AutoImageProcessor, DetrForObjectDetection
>>> import torch
>>> from PIL import Image
>>> import requests
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> image_processor = AutoImageProcessor.from_pretrained("facebook/detr-resnet-50")
>>> model = DetrForObjectDetection.from_pretrained("facebook/detr-resnet-50")
>>> inputs = image_processor(images=image, return_tensors="pt")
>>> outputs = model(**inputs)
>>> # convert outputs (bounding boxes and class logits) to Pascal VOC format (xmin, ymin, xmax, ymax)
>>> target_sizes = torch.tensor([image.size[::-1]])
>>> results = image_processor.post_process_object_detection(outputs, threshold=0.9, target_sizes=target_sizes)[
... 0
... ]
>>> for score, label, box in zip(results["scores"], results["labels"], results["boxes"]):
... box = [round(i, 2) for i in box.tolist()]
... print(
... f"Detected {model.config.id2label[label.item()]} with confidence "
... f"{round(score.item(), 3)} at location {box}"
... )
Detected remote with confidence 0.998 at location [40.16, 70.81, 175.55, 117.98]
Detected remote with confidence 0.996 at location [333.24, 72.55, 368.33, 187.66]
Detected couch with confidence 0.995 at location [-0.02, 1.15, 639.73, 473.76]
Detected cat with confidence 0.999 at location [13.24, 52.05, 314.02, 470.93]
Detected cat with confidence 0.999 at location [345.4, 23.85, 640.37, 368.72]
```"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# First, sent images through DETR base model to obtain encoder + decoder outputs
outputs = self.model(
pixel_values,
pixel_mask=pixel_mask,
decoder_attention_mask=decoder_attention_mask,
encoder_outputs=encoder_outputs,
inputs_embeds=inputs_embeds,
decoder_inputs_embeds=decoder_inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
sequence_output = outputs[0]
# class logits + predicted bounding boxes
logits = self.class_labels_classifier(sequence_output)
pred_boxes = self.bbox_predictor(sequence_output).sigmoid()
loss, loss_dict, auxiliary_outputs = None, None, None
if labels is not None:
outputs_class, outputs_coord = None, None
if self.config.auxiliary_loss:
intermediate = outputs.intermediate_hidden_states if return_dict else outputs[4]
outputs_class = self.class_labels_classifier(intermediate)
outputs_coord = self.bbox_predictor(intermediate).sigmoid()
loss, loss_dict, auxiliary_outputs = self.loss_function(
logits, labels, self.device, pred_boxes, self.config, outputs_class, outputs_coord
)
if not return_dict:
if auxiliary_outputs is not None:
output = (logits, pred_boxes) + auxiliary_outputs + outputs
else:
output = (logits, pred_boxes) + outputs
return ((loss, loss_dict) + output) if loss is not None else output
return DetrObjectDetectionOutput(
loss=loss,
loss_dict=loss_dict,
logits=logits,
pred_boxes=pred_boxes,
auxiliary_outputs=auxiliary_outputs,
last_hidden_state=outputs.last_hidden_state,
decoder_hidden_states=outputs.decoder_hidden_states,
decoder_attentions=outputs.decoder_attentions,
cross_attentions=outputs.cross_attentions,
encoder_last_hidden_state=outputs.encoder_last_hidden_state,
encoder_hidden_states=outputs.encoder_hidden_states,
encoder_attentions=outputs.encoder_attentions,
)
@auto_docstring(
custom_intro="""
DETR Model (consisting of a backbone and encoder-decoder Transformer) with a segmentation head on top, for tasks
such as COCO panoptic.
"""
)
class DetrForSegmentation(DetrPreTrainedModel):
def __init__(self, config: DetrConfig):
super().__init__(config)
# object detection model
self.detr = DetrForObjectDetection(config)
# segmentation head
hidden_size, number_of_heads = config.d_model, config.encoder_attention_heads
intermediate_channel_sizes = self.detr.model.backbone.conv_encoder.intermediate_channel_sizes
self.mask_head = DetrMaskHeadSmallConv(
hidden_size + number_of_heads, intermediate_channel_sizes[::-1][-3:], hidden_size
)
self.bbox_attention = DetrMHAttentionMap(
hidden_size, hidden_size, number_of_heads, dropout=0.0, std=config.init_xavier_std
)
# Initialize weights and apply final processing
self.post_init()
@auto_docstring
def forward(
self,
pixel_values: torch.FloatTensor,
pixel_mask: Optional[torch.LongTensor] = None,
decoder_attention_mask: Optional[torch.FloatTensor] = None,
encoder_outputs: Optional[torch.FloatTensor] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
decoder_inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[list[dict]] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[tuple[torch.FloatTensor], DetrSegmentationOutput]:
r"""
decoder_attention_mask (`torch.FloatTensor` of shape `(batch_size, num_queries)`, *optional*):
Not used by default. Can be used to mask object queries.
inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
Optionally, instead of passing the flattened feature map (output of the backbone + projection layer), you
can choose to directly pass a flattened representation of an image.
decoder_inputs_embeds (`torch.FloatTensor` of shape `(batch_size, num_queries, hidden_size)`, *optional*):
Optionally, instead of initializing the queries with a tensor of zeros, you can choose to directly pass an
embedded representation.
labels (`list[Dict]` of len `(batch_size,)`, *optional*):
Labels for computing the bipartite matching loss, DICE/F-1 loss and Focal loss. List of dicts, each
dictionary containing at least the following 3 keys: 'class_labels', 'boxes' and 'masks' (the class labels,
bounding boxes and segmentation masks of an image in the batch respectively). The class labels themselves
should be a `torch.LongTensor` of len `(number of bounding boxes in the image,)`, the boxes a
`torch.FloatTensor` of shape `(number of bounding boxes in the image, 4)` and the masks a
`torch.FloatTensor` of shape `(number of bounding boxes in the image, height, width)`.
Examples:
```python
>>> import io
>>> import requests
>>> from PIL import Image
>>> import torch
>>> import numpy
>>> from transformers import AutoImageProcessor, DetrForSegmentation
>>> from transformers.image_transforms import rgb_to_id
>>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
>>> image = Image.open(requests.get(url, stream=True).raw)
>>> image_processor = AutoImageProcessor.from_pretrained("facebook/detr-resnet-50-panoptic")
>>> model = DetrForSegmentation.from_pretrained("facebook/detr-resnet-50-panoptic")
>>> # prepare image for the model
>>> inputs = image_processor(images=image, return_tensors="pt")
>>> # forward pass
>>> outputs = model(**inputs)
>>> # Use the `post_process_panoptic_segmentation` method of the `image_processor` to retrieve post-processed panoptic segmentation maps
>>> # Segmentation results are returned as a list of dictionaries
>>> result = image_processor.post_process_panoptic_segmentation(outputs, target_sizes=[(300, 500)])
>>> # A tensor of shape (height, width) where each value denotes a segment id, filled with -1 if no segment is found
>>> panoptic_seg = result[0]["segmentation"]
>>> # Get prediction score and segment_id to class_id mapping of each segment
>>> panoptic_segments_info = result[0]["segments_info"]
```"""
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
batch_size, num_channels, height, width = pixel_values.shape
device = pixel_values.device
if pixel_mask is None:
pixel_mask = torch.ones((batch_size, height, width), device=device)
# First, get list of feature maps and position embeddings
features, object_queries_list = self.detr.model.backbone(pixel_values, pixel_mask=pixel_mask)
# Second, apply 1x1 convolution to reduce the channel dimension to d_model (256 by default)
feature_map, mask = features[-1]
batch_size, num_channels, height, width = feature_map.shape
projected_feature_map = self.detr.model.input_projection(feature_map)
# Third, flatten the feature map + position embeddings of shape NxCxHxW to NxCxHW, and permute it to NxHWxC
# In other words, turn their shape into (batch_size, sequence_length, hidden_size)
flattened_features = projected_feature_map.flatten(2).permute(0, 2, 1)
object_queries = object_queries_list[-1].flatten(2).permute(0, 2, 1)
flattened_mask = mask.flatten(1)
# Fourth, sent flattened_features + flattened_mask + position embeddings through encoder
# flattened_features is a Tensor of shape (batch_size, height*width, hidden_size)
# flattened_mask is a Tensor of shape (batch_size, height*width)
if encoder_outputs is None:
encoder_outputs = self.detr.model.encoder(
inputs_embeds=flattened_features,
attention_mask=flattened_mask,
object_queries=object_queries,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
# If the user passed a tuple for encoder_outputs, we wrap it in a BaseModelOutput when return_dict=True
elif return_dict and not isinstance(encoder_outputs, BaseModelOutput):
encoder_outputs = BaseModelOutput(
last_hidden_state=encoder_outputs[0],
hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None,
attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None,
)
# Fifth, sent query embeddings + position embeddings through the decoder (which is conditioned on the encoder output)
query_position_embeddings = self.detr.model.query_position_embeddings.weight.unsqueeze(0).repeat(
batch_size, 1, 1
)
queries = torch.zeros_like(query_position_embeddings)
# decoder outputs consists of (dec_features, dec_hidden, dec_attn)
decoder_outputs = self.detr.model.decoder(
inputs_embeds=queries,
attention_mask=None,
object_queries=object_queries,
query_position_embeddings=query_position_embeddings,
encoder_hidden_states=encoder_outputs[0],
encoder_attention_mask=flattened_mask,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
)
sequence_output = decoder_outputs[0]
# Sixth, compute logits, pred_boxes and pred_masks
logits = self.detr.class_labels_classifier(sequence_output)
pred_boxes = self.detr.bbox_predictor(sequence_output).sigmoid()
memory = encoder_outputs[0].permute(0, 2, 1).view(batch_size, self.config.d_model, height, width)
mask = flattened_mask.view(batch_size, height, width)
# FIXME h_boxes takes the last one computed, keep this in mind
# important: we need to reverse the mask, since in the original implementation the mask works reversed
# bbox_mask is of shape (batch_size, num_queries, number_of_attention_heads in bbox_attention, height/32, width/32)
bbox_mask = self.bbox_attention(sequence_output, memory, mask=~mask)
seg_masks = self.mask_head(projected_feature_map, bbox_mask, [features[2][0], features[1][0], features[0][0]])
pred_masks = seg_masks.view(batch_size, self.detr.config.num_queries, seg_masks.shape[-2], seg_masks.shape[-1])
loss, loss_dict, auxiliary_outputs = None, None, None
if labels is not None:
outputs_class, outputs_coord = None, None
if self.config.auxiliary_loss:
intermediate = decoder_outputs.intermediate_hidden_states if return_dict else decoder_outputs[-1]
outputs_class = self.detr.class_labels_classifier(intermediate)
outputs_coord = self.detr.bbox_predictor(intermediate).sigmoid()
loss, loss_dict, auxiliary_outputs = self.loss_function(
logits, labels, device, pred_boxes, pred_masks, self.config, outputs_class, outputs_coord
)
if not return_dict:
if auxiliary_outputs is not None:
output = (logits, pred_boxes, pred_masks) + auxiliary_outputs + decoder_outputs + encoder_outputs
else:
output = (logits, pred_boxes, pred_masks) + decoder_outputs + encoder_outputs
return ((loss, loss_dict) + output) if loss is not None else output
return DetrSegmentationOutput(
loss=loss,
loss_dict=loss_dict,
logits=logits,
pred_boxes=pred_boxes,
pred_masks=pred_masks,
auxiliary_outputs=auxiliary_outputs,
last_hidden_state=decoder_outputs.last_hidden_state,
decoder_hidden_states=decoder_outputs.hidden_states,
decoder_attentions=decoder_outputs.attentions,
cross_attentions=decoder_outputs.cross_attentions,
encoder_last_hidden_state=encoder_outputs.last_hidden_state,
encoder_hidden_states=encoder_outputs.hidden_states,
encoder_attentions=encoder_outputs.attentions,
)
def _expand(tensor, length: int):
return tensor.unsqueeze(1).repeat(1, int(length), 1, 1, 1).flatten(0, 1)
# taken from https://github.com/facebookresearch/detr/blob/master/models/segmentation.py
class DetrMaskHeadSmallConv(nn.Module):
"""
Simple convolutional head, using group norm. Upsampling is done using a FPN approach
"""
def __init__(self, dim, fpn_dims, context_dim):
super().__init__()
if dim % 8 != 0:
raise ValueError(
"The hidden_size + number of attention heads must be divisible by 8 as the number of groups in"
" GroupNorm is set to 8"
)
inter_dims = [dim, context_dim // 2, context_dim // 4, context_dim // 8, context_dim // 16, context_dim // 64]
self.lay1 = nn.Conv2d(dim, dim, 3, padding=1)
self.gn1 = nn.GroupNorm(8, dim)
self.lay2 = nn.Conv2d(dim, inter_dims[1], 3, padding=1)
self.gn2 = nn.GroupNorm(min(8, inter_dims[1]), inter_dims[1])
self.lay3 = nn.Conv2d(inter_dims[1], inter_dims[2], 3, padding=1)
self.gn3 = nn.GroupNorm(min(8, inter_dims[2]), inter_dims[2])
self.lay4 = nn.Conv2d(inter_dims[2], inter_dims[3], 3, padding=1)
self.gn4 = nn.GroupNorm(min(8, inter_dims[3]), inter_dims[3])
self.lay5 = nn.Conv2d(inter_dims[3], inter_dims[4], 3, padding=1)
self.gn5 = nn.GroupNorm(min(8, inter_dims[4]), inter_dims[4])
self.out_lay = nn.Conv2d(inter_dims[4], 1, 3, padding=1)
self.dim = dim
self.adapter1 = nn.Conv2d(fpn_dims[0], inter_dims[1], 1)
self.adapter2 = nn.Conv2d(fpn_dims[1], inter_dims[2], 1)
self.adapter3 = nn.Conv2d(fpn_dims[2], inter_dims[3], 1)
for m in self.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_uniform_(m.weight, a=1)
nn.init.constant_(m.bias, 0)
def forward(self, x: Tensor, bbox_mask: Tensor, fpns: list[Tensor]):
# here we concatenate x, the projected feature map, of shape (batch_size, d_model, height/32, width/32) with
# the bbox_mask = the attention maps of shape (batch_size, n_queries, n_heads, height/32, width/32).
# We expand the projected feature map to match the number of heads.
x = torch.cat([_expand(x, bbox_mask.shape[1]), bbox_mask.flatten(0, 1)], 1)
x = self.lay1(x)
x = self.gn1(x)
x = nn.functional.relu(x)
x = self.lay2(x)
x = self.gn2(x)
x = nn.functional.relu(x)
cur_fpn = self.adapter1(fpns[0])
if cur_fpn.size(0) != x.size(0):
cur_fpn = _expand(cur_fpn, x.size(0) // cur_fpn.size(0))
x = cur_fpn + nn.functional.interpolate(x, size=cur_fpn.shape[-2:], mode="nearest")
x = self.lay3(x)
x = self.gn3(x)
x = nn.functional.relu(x)
cur_fpn = self.adapter2(fpns[1])
if cur_fpn.size(0) != x.size(0):
cur_fpn = _expand(cur_fpn, x.size(0) // cur_fpn.size(0))
x = cur_fpn + nn.functional.interpolate(x, size=cur_fpn.shape[-2:], mode="nearest")
x = self.lay4(x)
x = self.gn4(x)
x = nn.functional.relu(x)
cur_fpn = self.adapter3(fpns[2])
if cur_fpn.size(0) != x.size(0):
cur_fpn = _expand(cur_fpn, x.size(0) // cur_fpn.size(0))
x = cur_fpn + nn.functional.interpolate(x, size=cur_fpn.shape[-2:], mode="nearest")
x = self.lay5(x)
x = self.gn5(x)
x = nn.functional.relu(x)
x = self.out_lay(x)
return x
class DetrMHAttentionMap(nn.Module):
"""This is a 2D attention module, which only returns the attention softmax (no multiplication by value)"""
def __init__(self, query_dim, hidden_dim, num_heads, dropout=0.0, bias=True, std=None):
super().__init__()
self.num_heads = num_heads
self.hidden_dim = hidden_dim
self.dropout = nn.Dropout(dropout)
self.q_linear = nn.Linear(query_dim, hidden_dim, bias=bias)
self.k_linear = nn.Linear(query_dim, hidden_dim, bias=bias)
self.normalize_fact = float(hidden_dim / self.num_heads) ** -0.5
def forward(self, q, k, mask: Optional[Tensor] = None):
q = self.q_linear(q)
k = nn.functional.conv2d(k, self.k_linear.weight.unsqueeze(-1).unsqueeze(-1), self.k_linear.bias)
queries_per_head = q.view(q.shape[0], q.shape[1], self.num_heads, self.hidden_dim // self.num_heads)
keys_per_head = k.view(k.shape[0], self.num_heads, self.hidden_dim // self.num_heads, k.shape[-2], k.shape[-1])
weights = torch.einsum("bqnc,bnchw->bqnhw", queries_per_head * self.normalize_fact, keys_per_head)
if mask is not None:
weights = weights.masked_fill(mask.unsqueeze(1).unsqueeze(1), torch.finfo(weights.dtype).min)
weights = nn.functional.softmax(weights.flatten(2), dim=-1).view(weights.size())
weights = self.dropout(weights)
return weights
__all__ = [
"DetrForObjectDetection",
"DetrForSegmentation",
"DetrModel",
"DetrPreTrainedModel",
]