# coding=utf-8
# Copyright 2018 The Google AI Language Team Authors, The HuggingFace Inc. team, and the
# Lxmert Authors.
# Copyright (c) 2018, NVIDIA CORPORATION. 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.
""" TF 2.0 LXMERT model. """
import warnings
from dataclasses import dataclass
from typing import Dict, Optional, Tuple
import tensorflow as tf
from ...activations_tf import get_tf_activation
from ...file_utils import (
ModelOutput,
add_code_sample_docstrings,
add_start_docstrings,
add_start_docstrings_to_model_forward,
replace_return_docstrings,
)
from ...modeling_tf_utils import TFPreTrainedModel, get_initializer, input_processing, keras_serializable, shape_list
from ...utils import logging
from .configuration_lxmert import LxmertConfig
logger = logging.get_logger(__name__)
_CHECKPOINT_FOR_DOC = "unc-nlp/lxmert-base-uncased"
_CONFIG_FOR_DOC = "LxmertConfig"
_TOKENIZER_FOR_DOC = "LxmertTokenizer"
TF_LXMERT_PRETRAINED_MODEL_ARCHIVE_LIST = [
"unc-nlp/lxmert-base-uncased",
]
@dataclass
class TFLxmertModelOutput(ModelOutput):
"""
Lxmert's outputs that contain the last hidden states, pooled outputs, and attention probabilities for the language,
visual, and, cross-modality encoders. (note: the visual encoder in Lxmert is referred to as the "relation-ship"
encoder")
Args:
language_output (`tf.Tensor` of shape `(batch_size, sequence_length, hidden_size)`):
Sequence of hidden-states at the output of the last layer of the language encoder.
vision_output (`tf.Tensor` of shape `(batch_size, sequence_length, hidden_size)`):
Sequence of hidden-states at the output of the last layer of the visual encoder.
pooled_output (`tf.Tensor` of shape `(batch_size, hidden_size)`):
Last layer hidden-state of the first token of the sequence (classification, CLS, token) further processed
by a Linear layer and a Tanh activation function. The Linear
language_hidden_states (`tuple(tf.Tensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`):
Tuple of `tf.Tensor` (one for input features + one for the output of each cross-modality layer) of
shape `(batch_size, sequence_length, hidden_size)`.
vision_hidden_states (`tuple(tf.Tensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`):
Tuple of `tf.Tensor` (one for input features + one for the output of each cross-modality layer) of
shape `(batch_size, sequence_length, hidden_size)`.
language_attentions (`tuple(tf.Tensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
Tuple of `tf.Tensor` (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.
vision_attentions (`tuple(tf.Tensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
Tuple of `tf.Tensor` (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_encoder_attentions (`tuple(tf.Tensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
Tuple of `tf.Tensor` (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.
"""
language_output: Optional[tf.Tensor] = None
vision_output: Optional[tf.Tensor] = None
pooled_output: Optional[tf.Tensor] = None
language_hidden_states: Optional[Tuple[tf.Tensor]] = None
vision_hidden_states: Optional[Tuple[tf.Tensor]] = None
language_attentions: Optional[Tuple[tf.Tensor]] = None
vision_attentions: Optional[Tuple[tf.Tensor]] = None
cross_encoder_attentions: Optional[Tuple[tf.Tensor]] = None
@dataclass
class TFLxmertForPreTrainingOutput(ModelOutput):
"""
Output type of [`LxmertForPreTraining`].
Args:
loss (*optional*, returned when `labels` is provided, `tf.Tensor` of shape `(1,)`):
Total loss as the sum of the masked language modeling loss and the next sequence prediction
(classification) loss.
prediction_logits (`tf.Tensor` of shape `(batch_size, sequence_length, config.vocab_size)`):
Prediction scores of the language modeling head (scores for each vocabulary token before SoftMax).
cross_relationship_score: (`tf.Tensor` of shape `(batch_size, 2)`):
Prediction scores of the textual matching objective (classification) head (scores of True/False
continuation before SoftMax).
question_answering_score: (`tf.Tensor` of shape `(batch_size, n_qa_answers)`):
Prediction scores of question answering objective (classification).
language_hidden_states (`tuple(tf.Tensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`):
Tuple of `tf.Tensor` (one for input features + one for the output of each cross-modality layer) of
shape `(batch_size, sequence_length, hidden_size)`.
vision_hidden_states (`tuple(tf.Tensor)`, *optional*, returned when `output_hidden_states=True` is passed or when `config.output_hidden_states=True`):
Tuple of `tf.Tensor` (one for input features + one for the output of each cross-modality layer) of
shape `(batch_size, sequence_length, hidden_size)`.
language_attentions (`tuple(tf.Tensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
Tuple of `tf.Tensor` (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.
vision_attentions (`tuple(tf.Tensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
Tuple of `tf.Tensor` (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_encoder_attentions (`tuple(tf.Tensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
Tuple of `tf.Tensor` (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.
"""
loss: Optional[tf.Tensor] = None
prediction_logits: Optional[tf.Tensor] = None
cross_relationship_score: Optional[tf.Tensor] = None
question_answering_score: Optional[tf.Tensor] = None
language_hidden_states: Optional[Tuple[tf.Tensor]] = None
vision_hidden_states: Optional[Tuple[tf.Tensor]] = None
language_attentions: Optional[Tuple[tf.Tensor]] = None
vision_attentions: Optional[Tuple[tf.Tensor]] = None
cross_encoder_attentions: Optional[Tuple[tf.Tensor]] = None
class TFLxmertVisualFeatureEncoder(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
# Object feature encoding
self.visn_fc = tf.keras.layers.Dense(
config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
name="visn_fc",
)
self.visn_layer_norm = tf.keras.layers.LayerNormalization(
epsilon=config.layer_norm_eps, name="visn_layer_norm"
)
# Box position encoding
self.box_fc = tf.keras.layers.Dense(
config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
name="box_fc",
)
self.box_layer_norm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="box_layer_norm")
self.dropout = tf.keras.layers.Dropout(config.hidden_dropout_prob)
def call(self, visn_input, training=False):
feats, boxes = visn_input
x = self.visn_fc(feats)
x = self.visn_layer_norm(x)
y = self.box_fc(boxes)
y = self.box_layer_norm(y)
output = (x + y) / 2
output = self.dropout(output, training=training)
return output
class TFLxmertEmbeddings(tf.keras.layers.Layer):
"""Construct the embeddings from word, position and token_type embeddings."""
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.vocab_size = config.vocab_size
self.type_vocab_size = config.type_vocab_size
self.hidden_size = config.hidden_size
self.max_position_embeddings = config.max_position_embeddings
self.initializer_range = config.initializer_range
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
self.dropout = tf.keras.layers.Dropout(rate=config.hidden_dropout_prob)
def build(self, input_shape):
with tf.name_scope("word_embeddings"):
self.weight = self.add_weight(
name="weight",
shape=[self.vocab_size, self.hidden_size],
initializer=get_initializer(initializer_range=self.initializer_range),
)
with tf.name_scope("token_type_embeddings"):
self.token_type_embeddings = self.add_weight(
name="embeddings",
shape=[self.type_vocab_size, self.hidden_size],
initializer=get_initializer(initializer_range=self.initializer_range),
)
with tf.name_scope("position_embeddings"):
self.position_embeddings = self.add_weight(
name="embeddings",
shape=[self.max_position_embeddings, self.hidden_size],
initializer=get_initializer(initializer_range=self.initializer_range),
)
super().build(input_shape)
def call(self, input_ids=None, token_type_ids=None, inputs_embeds=None, training=False):
"""
Applies embedding based on inputs tensor.
Returns:
final_embeddings (`tf.Tensor`): output embedding tensor.
"""
assert not (input_ids is None and inputs_embeds is None)
if input_ids is not None:
inputs_embeds = tf.gather(params=self.weight, indices=input_ids)
input_shape = shape_list(inputs_embeds)[:-1]
if token_type_ids is None:
token_type_ids = tf.fill(dims=input_shape, value=0)
position_ids = tf.expand_dims(tf.range(start=0, limit=input_shape[-1]), axis=0)
position_embeds = tf.gather(params=self.position_embeddings, indices=position_ids)
token_type_embeds = tf.gather(params=self.token_type_embeddings, indices=token_type_ids)
final_embeddings = inputs_embeds + position_embeds + token_type_embeds
final_embeddings = self.LayerNorm(inputs=final_embeddings)
final_embeddings = self.dropout(inputs=final_embeddings, training=training)
return final_embeddings
class TFLxmertAttention(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
if config.hidden_size % config.num_attention_heads != 0:
raise ValueError(
f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention "
f"heads ({config.num_attention_heads}"
)
self.num_attention_heads = config.num_attention_heads
assert config.hidden_size % config.num_attention_heads == 0
self.attention_head_size = int(config.hidden_size / config.num_attention_heads)
self.all_head_size = self.num_attention_heads * self.attention_head_size
self.query = tf.keras.layers.Dense(
self.all_head_size,
kernel_initializer=get_initializer(config.initializer_range),
name="query",
)
self.key = tf.keras.layers.Dense(
self.all_head_size,
kernel_initializer=get_initializer(config.initializer_range),
name="key",
)
self.value = tf.keras.layers.Dense(
self.all_head_size,
kernel_initializer=get_initializer(config.initializer_range),
name="value",
)
self.dropout = tf.keras.layers.Dropout(config.attention_probs_dropout_prob)
def transpose_for_scores(self, x, batch_size):
# Reshape from [batch_size, seq_length, all_head_size] to [batch_size, seq_length, num_attention_heads, attention_head_size]
x = tf.reshape(x, (batch_size, -1, self.num_attention_heads, self.attention_head_size))
return tf.transpose(x, perm=[0, 2, 1, 3])
def call(self, hidden_states, context, attention_mask, output_attentions, training=False):
batch_size = shape_list(hidden_states)[0]
mixed_query_layer = self.query(hidden_states)
mixed_key_layer = self.key(context)
mixed_value_layer = self.value(context)
query_layer = self.transpose_for_scores(mixed_query_layer, batch_size)
key_layer = self.transpose_for_scores(mixed_key_layer, batch_size)
value_layer = self.transpose_for_scores(mixed_value_layer, batch_size)
# Take the dot product between "query" and "key" to get the raw attention scores.
attention_scores = tf.matmul(
query_layer, key_layer, transpose_b=True
) # (batch size, num_heads, seq_len_q, seq_len_k)
dk = tf.cast(shape_list(key_layer)[-1], dtype=attention_scores.dtype) # scale attention_scores
attention_scores = attention_scores / tf.math.sqrt(dk)
if attention_mask is not None:
# Apply the attention mask is (precomputed for all layers in TFLxmertModel call() function)
attention_mask = tf.cast(attention_mask, dtype=attention_scores.dtype)
attention_scores = attention_scores + attention_mask
# Normalize the attention scores to probabilities.
attention_probs = tf.nn.softmax(attention_scores, axis=-1)
# This is actually dropping out entire tokens to attend to, which might
# seem a bit unusual, but is taken from the original Transformer paper.
attention_probs = self.dropout(attention_probs, training=training)
context_layer = tf.matmul(attention_probs, value_layer)
context_layer = tf.transpose(context_layer, perm=[0, 2, 1, 3])
context_layer = tf.reshape(
context_layer, (batch_size, -1, self.all_head_size)
) # (batch_size, seq_len_q, all_head_size)
outputs = (context_layer, attention_probs) if output_attentions else (context_layer,)
return outputs
class TFLxmertIntermediate(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
config.intermediate_size,
kernel_initializer=get_initializer(config.initializer_range),
name="dense",
)
if isinstance(config.hidden_act, str):
self.intermediate_act_fn = get_tf_activation(config.hidden_act)
else:
self.intermediate_act_fn = config.hidden_act
def call(self, hidden_states):
hidden_states = self.dense(hidden_states)
hidden_states = self.intermediate_act_fn(hidden_states)
return hidden_states
class TFLxmertOutput(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
name="dense",
)
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
self.dropout = tf.keras.layers.Dropout(config.hidden_dropout_prob)
def call(self, hidden_states, input_tensor, training=False):
hidden_states = self.dense(hidden_states)
hidden_states = self.dropout(hidden_states, training)
hidden_states = self.LayerNorm(hidden_states + input_tensor)
return hidden_states
class TFLxmertAttentionOutput(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
name="dense",
)
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
self.dropout = tf.keras.layers.Dropout(config.hidden_dropout_prob)
def call(self, hidden_states, input_tensor, training=False):
hidden_states = self.dense(hidden_states)
hidden_states = self.dropout(hidden_states, training=training)
hidden_states = self.LayerNorm(hidden_states + input_tensor)
return hidden_states
class TFLxmertSelfAttentionLayer(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.self = TFLxmertAttention(config, name="self")
self.attention_output = TFLxmertAttentionOutput(config, name="output")
def call(self, input_tensor, attention_mask, output_attentions, training=False):
# Self attention attends to itself, thus keys and queries are the same (input_tensor).
self_output = self.self(input_tensor, input_tensor, attention_mask, output_attentions)
if output_attentions:
attention_probs = self_output[1]
attention_output = self.attention_output(self_output[0], input_tensor)
return (attention_output, attention_probs) if output_attentions else (attention_output,)
class TFLxmertCrossAttentionLayer(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.att = TFLxmertAttention(config, name="att")
self.attention_output = TFLxmertAttentionOutput(config, name="output")
def call(
self,
input_tensor,
ctx_tensor,
ctx_att_mask,
output_attentions=False,
training=False,
):
output = self.att(input_tensor, ctx_tensor, ctx_att_mask, output_attentions, training=training)
if output_attentions:
attention_probs = output[1]
attention_output = self.attention_output(output[0], input_tensor, training=training)
outputs = (attention_output, attention_probs) if output_attentions else (attention_output,)
return outputs
class TFLxmertLayer(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.attention = TFLxmertSelfAttentionLayer(config, name="attention")
self.intermediate = TFLxmertIntermediate(config, name="intermediate")
self.transformer_output = TFLxmertOutput(config, name="output")
def call(self, hidden_states, attention_mask, output_attentions, training=False):
attention_outputs = self.attention(hidden_states, attention_mask, output_attentions, training=training)
attention_output = attention_outputs[0]
intermediate_output = self.intermediate(attention_output)
layer_output = self.transformer_output(intermediate_output, attention_output, training=training)
outputs = (layer_output,) + attention_outputs[1:] # add attentions if we output them
return outputs
class TFLxmertXLayer(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.visual_attention = TFLxmertCrossAttentionLayer(config, name="visual_attention")
# Self-attention Layers
self.lang_self_att = TFLxmertSelfAttentionLayer(config, name="lang_self_att")
self.visn_self_att = TFLxmertSelfAttentionLayer(config, name="visn_self_att")
# Intermediate and Output Layers (FFNs)
self.lang_inter = TFLxmertIntermediate(config, name="lang_inter")
self.lang_output = TFLxmertOutput(config, name="lang_output")
self.visn_inter = TFLxmertIntermediate(config, name="visn_inter")
self.visn_output = TFLxmertOutput(config, name="visn_output")
def cross_att(
self,
lang_input,
lang_attention_mask,
visn_input,
visn_attention_mask,
output_attentions,
training=False,
):
# Cross Attention
# Keras saving and loading model *does not work* with the same inputs for two layers.
lang_attention_lang_input = tf.identity(lang_input)
visn_attention_lang_input = tf.identity(lang_input)
lang_attention_visn_input = tf.identity(visn_input)
visn_attention_visn_input = tf.identity(visn_input)
lang_att_output = self.visual_attention(
lang_attention_lang_input,
lang_attention_visn_input,
visn_attention_mask,
output_attentions=output_attentions,
training=training,
)
visn_att_output = self.visual_attention(
visn_attention_visn_input,
visn_attention_lang_input,
lang_attention_mask,
output_attentions=output_attentions,
training=training,
)
return lang_att_output, visn_att_output
def self_att(
self,
lang_input,
lang_attention_mask,
visn_input,
visn_attention_mask,
training=False,
):
# Self Attention
output_attentions = False
lang_att_output = self.lang_self_att(lang_input, lang_attention_mask, output_attentions, training=training)
visn_att_output = self.visn_self_att(visn_input, visn_attention_mask, output_attentions, training=training)
return lang_att_output[0], visn_att_output[0]
def output_fc(self, lang_input, visn_input, training=False):
# FC layers
lang_inter_output = self.lang_inter(lang_input)
visn_inter_output = self.visn_inter(visn_input)
# Layer output
lang_output = self.lang_output(lang_inter_output, lang_input, training)
visn_output = self.visn_output(visn_inter_output, visn_input, training)
return lang_output, visn_output
def call(
self,
lang_feats,
lang_attention_mask,
visn_feats,
visn_attention_mask,
output_attentions,
training=False,
):
lang_att_output = lang_feats
visn_att_output = visn_feats
lang_att_output, visn_att_output = self.cross_att(
lang_att_output,
lang_attention_mask,
visn_att_output,
visn_attention_mask,
output_attentions,
training=training,
)
attention_probs = lang_att_output[1:]
lang_att_output, visn_att_output = self.self_att(
lang_att_output[0],
lang_attention_mask,
visn_att_output[0],
visn_attention_mask,
training=training,
)
lang_output, visn_output = self.output_fc(lang_att_output, visn_att_output, training=training)
return (lang_output, visn_output, attention_probs[0]) if output_attentions else (lang_output, visn_output)
class TFLxmertEncoder(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.visn_fc = TFLxmertVisualFeatureEncoder(config, name="visn_fc")
# Number of layers
self.num_l_layers = config.l_layers
self.num_x_layers = config.x_layers
self.num_r_layers = config.r_layers
# Layers
# Using self.layer instead of self.l_layer to support loading BERT weights.
self.layer = [TFLxmertLayer(config, name=f"layer_._{i}") for i in range(self.num_l_layers)]
self.x_layers = [TFLxmertXLayer(config, name=f"x_layers_._{i}") for i in range(self.num_x_layers)]
self.r_layers = [TFLxmertLayer(config, name=f"r_layers_._{i}") for i in range(self.num_r_layers)]
self.config = config
def call(
self,
lang_feats=None,
lang_attention_mask=None,
visual_feats=None,
visual_pos=None,
visual_attention_mask=None,
output_attentions=None,
training=False,
):
vision_hidden_states = ()
language_hidden_states = ()
vision_attentions = () if output_attentions or self.config.output_attentions else None
language_attentions = () if output_attentions or self.config.output_attentions else None
cross_encoder_attentions = () if output_attentions or self.config.output_attentions else None
visual_feats = self.visn_fc([visual_feats, visual_pos], training=training)
# Run language layers
for layer_module in self.layer:
l_outputs = layer_module(lang_feats, lang_attention_mask, output_attentions, training=training)
lang_feats = l_outputs[0]
language_hidden_states = language_hidden_states + (lang_feats,)
if language_attentions is not None:
language_attentions = language_attentions + (l_outputs[1],)
# Run relational layers
for layer_module in self.r_layers:
v_outputs = layer_module(
visual_feats,
visual_attention_mask,
output_attentions,
training=training,
)
visual_feats = v_outputs[0]
vision_hidden_states = vision_hidden_states + (visual_feats,)
if vision_attentions is not None:
vision_attentions = vision_attentions + (v_outputs[1],)
# Run cross-modality layers
for layer_module in self.x_layers:
x_outputs = layer_module(
lang_feats,
lang_attention_mask,
visual_feats,
visual_attention_mask,
output_attentions,
training=training,
)
lang_feats, visual_feats = x_outputs[:2]
vision_hidden_states = vision_hidden_states + (visual_feats,)
language_hidden_states = language_hidden_states + (lang_feats,)
if cross_encoder_attentions is not None:
cross_encoder_attentions = cross_encoder_attentions + (x_outputs[2],)
visual_encoder_outputs = (
vision_hidden_states,
vision_attentions if output_attentions else None,
)
lang_encoder_outputs = (
language_hidden_states,
language_attentions if output_attentions else None,
)
return (
visual_encoder_outputs,
lang_encoder_outputs,
cross_encoder_attentions if output_attentions else None,
)
@keras_serializable
class TFLxmertMainLayer(tf.keras.layers.Layer):
config_class = LxmertConfig
@property
def dummy_inputs(self):
"""
Dummy inputs to build the network.
Returns:
tf.Tensor with dummy inputs
"""
batch_size = 2
num_visual_features = 10
input_ids = tf.constant([[3, 5, 6], [2, 3, 4]])
visual_feats = tf.random.uniform((batch_size, num_visual_features, self.config.visual_feat_dim))
visual_pos = tf.random.uniform((batch_size, num_visual_features, 4))
return {
"input_ids": input_ids,
"visual_feats": visual_feats,
"visual_pos": visual_pos,
}
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.config = config
self.num_l_layers = config.l_layers
self.num_x_layers = config.x_layers
self.num_r_layers = config.r_layers
self.initializer_range = config.initializer_range
self.output_attentions = config.output_attentions
self.output_hidden_states = config.output_hidden_states
self.return_dict = config.use_return_dict
self.embeddings = TFLxmertEmbeddings(config, name="embeddings")
self.encoder = TFLxmertEncoder(config, name="encoder")
self.pooler = TFLxmertPooler(config, name="pooler")
self.config = config
def get_input_embeddings(self):
return self.embeddings
def set_input_embeddings(self, value):
self.embeddings.weight = value
self.embeddings.vocab_size = shape_list(value)[0]
def _prune_heads(self, heads_to_prune):
raise NotImplementedError
def call(
self,
input_ids=None,
visual_feats=None,
visual_pos=None,
attention_mask=None,
visual_attention_mask=None,
token_type_ids=None,
inputs_embeds=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
training=False,
**kwargs,
):
inputs = input_processing(
func=self.call,
config=self.config,
input_ids=input_ids,
visual_feats=visual_feats,
visual_pos=visual_pos,
attention_mask=attention_mask,
visual_attention_mask=visual_attention_mask,
token_type_ids=token_type_ids,
inputs_embeds=inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
training=training,
kwargs_call=kwargs,
)
if inputs["input_ids"] is not None and inputs["inputs_embeds"] is not None:
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
elif inputs["input_ids"] is not None:
input_shape = shape_list(inputs["input_ids"])
elif inputs["inputs_embeds"] is not None:
input_shape = shape_list(inputs["inputs_embeds"])[:-1]
else:
raise ValueError("You have to specify either input_ids or inputs_embeds")
if inputs["visual_pos"] is None or inputs["visual_feats"] is None:
raise ValueError("visual_feats and visual_pos cannot be `None` in LXMERT's `call` method.")
if inputs["attention_mask"] is None:
inputs["attention_mask"] = tf.fill(input_shape, 1)
if inputs["token_type_ids"] is None:
inputs["token_type_ids"] = tf.fill(input_shape, 0)
# Positional Word Embeddings
embedding_output = self.embeddings(
inputs["input_ids"], inputs["token_type_ids"], inputs["inputs_embeds"], training=inputs["training"]
)
# We create a 3D attention mask from a 2D tensor mask.
# Sizes are [batch_size, 1, 1, to_seq_length]
# So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
# this attention mask is more simple than the triangular masking of causal attention
# used in OpenAI GPT, we just need to prepare the broadcast dimension here.
extended_attention_mask = tf.reshape(inputs["attention_mask"], (input_shape[0], 1, 1, input_shape[1]))
# Since attention_mask is 1.0 for positions we want to attend and 0.0 for
# masked positions, this operation will create a tensor which is 0.0 for
# positions we want to attend and -10000.0 for masked positions.
# Since we are adding it to the raw scores before the softmax, this is
# effectively the same as removing these entirely.
extended_attention_mask = tf.cast(extended_attention_mask, dtype=embedding_output.dtype)
one_cst = tf.constant(1.0, dtype=embedding_output.dtype)
ten_thousand_cst = tf.constant(-10000.0, dtype=embedding_output.dtype)
extended_attention_mask = tf.multiply(tf.subtract(one_cst, extended_attention_mask), ten_thousand_cst)
if inputs["visual_attention_mask"] is not None:
extended_visual_attention_mask = tf.reshape(
inputs["visual_attention_mask"], (input_shape[0], 1, 1, input_shape[1])
)
extended_visual_attention_mask = tf.expand_dims(
tf.expand_dims(inputs["visual_attention_mask"], axis=1), axis=1
)
extended_visual_attention_mask = tf.cast(extended_visual_attention_mask, dtype=embedding_output.dtype)
extended_visual_attention_mask = tf.multiply(
tf.subtract(one_cst, extended_visual_attention_mask), ten_thousand_cst
)
else:
extended_visual_attention_mask = None
# Run Lxmert encoder
encoder_outputs = self.encoder(
embedding_output,
extended_attention_mask,
inputs["visual_feats"],
inputs["visual_pos"],
extended_visual_attention_mask,
output_attentions=inputs["output_attentions"],
training=inputs["training"],
)
visual_encoder_outputs, lang_encoder_outputs = encoder_outputs[:2]
vision_hidden_states = visual_encoder_outputs[0]
language_hidden_states = lang_encoder_outputs[0]
all_attentions = ()
if inputs["output_attentions"]:
language_attentions = lang_encoder_outputs[1]
vision_attentions = visual_encoder_outputs[1]
cross_encoder_attentions = encoder_outputs[2]
all_attentions = (
language_attentions,
vision_attentions,
cross_encoder_attentions,
)
hidden_states = (language_hidden_states, vision_hidden_states) if inputs["output_hidden_states"] else ()
visual_output = vision_hidden_states[-1]
lang_output = language_hidden_states[-1]
pooled_output = self.pooler(lang_output)
if not inputs["return_dict"]:
return (lang_output, visual_output, pooled_output) + hidden_states + all_attentions
return TFLxmertModelOutput(
pooled_output=pooled_output,
language_output=lang_output,
vision_output=visual_output,
language_hidden_states=language_hidden_states if inputs["output_hidden_states"] else None,
vision_hidden_states=vision_hidden_states if inputs["output_hidden_states"] else None,
language_attentions=language_attentions if inputs["output_attentions"] else None,
vision_attentions=vision_attentions if inputs["output_attentions"] else None,
cross_encoder_attentions=cross_encoder_attentions if inputs["output_attentions"] else None,
)
class TFLxmertPreTrainedModel(TFPreTrainedModel):
"""
An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained
models.
"""
config_class = LxmertConfig
base_model_prefix = "lxmert"
@property
def dummy_inputs(self) -> Dict[str, tf.Tensor]:
return getattr(self, self.base_model_prefix).dummy_inputs
@tf.function(
input_signature=[
{
"input_ids": tf.TensorSpec((None, None), tf.int32, name="input_ids"),
"attention_mask": tf.TensorSpec((None, None), tf.int32, name="attention_mask"),
"visual_feats": tf.TensorSpec((None, None, None), tf.float32, name="visual_feats"),
"visual_pos": tf.TensorSpec((None, None, None), tf.float32, name="visual_pos"),
"visual_attention_mask": tf.TensorSpec((None, None), tf.int32, name="visual_attention_mask"),
"token_type_ids": tf.TensorSpec((None, None), tf.int32, name="token_type_ids"),
}
]
)
def serving(self, inputs):
output = self.call(inputs)
return self.serving_output(output)
LXMERT_START_DOCSTRING = r"""
The LXMERT model was proposed in [LXMERT: Learning Cross-Modality Encoder Representations from Transformers](https://arxiv.org/abs/1908.07490) by Hao Tan and Mohit Bansal. It's a vision and language transformer model,
pre-trained on a variety of multi-modal datasets comprising of GQA, VQAv2.0, MCSCOCO captions, and Visual genome,
using a combination of masked language modeling, region of interest feature regression, cross entropy loss for
question answering attribute prediction, and object tag prediction.
This model is also a [tf.keras.Model](https://www.tensorflow.org/api_docs/python/tf/keras/Model) subclass. Use
it as a regular TF 2.0 Keras Model and refer to the TF 2.0 documentation for all matter related to general usage
and behavior.
<Tip>
TF 2.0 models accepts two formats as inputs:
- having all inputs as keyword arguments (like PyTorch models), or
- having all inputs as a list, tuple or dict in the first positional arguments.
This second option is useful when using [`tf.keras.Model.fit`] method which currently requires having all
the tensors in the first argument of the model call function: `model(inputs)`.
If you choose this second option, there are three possibilities you can use to gather all the input Tensors in
the first positional argument :
- a single Tensor with `input_ids` only and nothing else: `model(inputs_ids)`
- a list of varying length with one or several input Tensors IN THE ORDER given in the docstring:
`model([input_ids, attention_mask])` or `model([input_ids, attention_mask, token_type_ids])`
- a dictionary with one or several input Tensors associated to the input names given in the docstring:
`model({"input_ids": input_ids, "token_type_ids": token_type_ids})`
</Tip>
Parameters:
config ([`LxmertConfig`]): 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.
"""
LXMERT_INPUTS_DOCSTRING = r"""
Args:
input_ids (`np.ndarray` or `tf.Tensor` of shape `(batch_size, sequence_length)`):
Indices of input sequence tokens in the vocabulary.
Indices can be obtained using [`LxmertTokenizer`]. See
[`PreTrainedTokenizer.__call__`] and [`PreTrainedTokenizer.encode`] for
details.
[What are input IDs?](../glossary#input-ids)
visual_feats: (`tf.Tensor` of shape `(batch_size, num_visual_features, visual_feat_dim)`):
This input represents visual features. They ROI pooled object features from bounding boxes using a
faster-RCNN model)
These are currently not provided by the transformers library.
visual_pos: (`tf.Tensor` of shape `(batch_size, num_visual_features, visual_feat_dim)`):
This input represents spacial features corresponding to their relative (via index) visual features. The
pre-trained LXMERT model expects these spacial features to be normalized bounding boxes on a scale of 0 to
1.
These are currently not provided by the transformers library.
attention_mask (`tf.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)
visual_attention_mask (`tf.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
MMask 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)
token_type_ids (`tf.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Segment token indices to indicate first and second portions of the inputs. Indices are selected in `[0, 1]`:
- 0 corresponds to a *sentence A* token,
- 1 corresponds to a *sentence B* token.
[What are token type IDs?](../glossary#token-type-ids)
inputs_embeds (`tf.Tensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*):
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.
output_attentions (`bool`, *optional*):
Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned
tensors for more detail. This argument can be used only in eager mode, in graph mode the value in the
config will be used instead.
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. This argument can be used only in eager mode, in graph mode the value in the config will be
used instead.
return_dict (`bool`, *optional*):
Whether or not to return a [`~file_utils.ModelOutput`] instead of a plain tuple. This
argument can be used in eager mode, in graph mode the value will always be set to True.
training (`bool`, *optional*, defaults to `False`):
Whether or not to use the model in training mode (some modules like dropout modules have different
behaviors between training and evaluation).
"""
@add_start_docstrings(
"The bare Lxmert Model transformer outputting raw hidden-states without any specific head on top.",
LXMERT_START_DOCSTRING,
)
class TFLxmertModel(TFLxmertPreTrainedModel):
def __init__(self, config, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.lxmert = TFLxmertMainLayer(config, name="lxmert")
@add_start_docstrings_to_model_forward(LXMERT_INPUTS_DOCSTRING)
@add_code_sample_docstrings(
processor_class=_TOKENIZER_FOR_DOC,
checkpoint=_CHECKPOINT_FOR_DOC,
output_type=TFLxmertModelOutput,
config_class=_CONFIG_FOR_DOC,
)
def call(
self,
input_ids=None,
visual_feats=None,
visual_pos=None,
attention_mask=None,
visual_attention_mask=None,
token_type_ids=None,
inputs_embeds=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
training=False,
**kwargs,
):
inputs = input_processing(
func=self.call,
config=self.config,
input_ids=input_ids,
visual_feats=visual_feats,
visual_pos=visual_pos,
attention_mask=attention_mask,
visual_attention_mask=visual_attention_mask,
token_type_ids=token_type_ids,
inputs_embeds=inputs_embeds,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
training=training,
kwargs_call=kwargs,
)
outputs = self.lxmert(
input_ids=inputs["input_ids"],
visual_feats=inputs["visual_feats"],
visual_pos=inputs["visual_pos"],
attention_mask=inputs["attention_mask"],
visual_attention_mask=inputs["visual_attention_mask"],
token_type_ids=inputs["token_type_ids"],
inputs_embeds=inputs["inputs_embeds"],
output_attentions=inputs["output_attentions"],
output_hidden_states=inputs["output_hidden_states"],
return_dict=inputs["return_dict"],
training=inputs["training"],
)
return outputs
def serving_output(self, output):
l_hs = tf.convert_to_tensor(output.language_hidden_states) if self.config.output_hidden_states else None
v_hs = tf.convert_to_tensor(output.vision_hidden_states) if self.config.output_hidden_states else None
l_attns = tf.convert_to_tensor(output.language_attentions) if self.config.output_attentions else None
v_attns = tf.convert_to_tensor(output.vision_attentions) if self.config.output_attentions else None
c_enc_attns = tf.convert_to_tensor(output.cross_encoder_attentions) if self.config.output_attentions else None
return TFLxmertModelOutput(
pooled_output=output.pooled_output,
language_output=output.language_output,
vision_output=output.vision_output,
language_hidden_states=l_hs,
vision_hidden_states=v_hs,
language_attentions=l_attns,
vision_attentions=v_attns,
cross_encoder_attentions=c_enc_attns,
)
class TFLxmertPooler(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
activation="tanh",
name="dense",
)
def call(self, hidden_states):
# We "pool" the model by simply taking the hidden state corresponding
# to the first token.
first_token_tensor = hidden_states[:, 0]
pooled_output = self.dense(first_token_tensor)
return pooled_output
# Copied from transformers.models.bert.modeling_tf_bert.TFBertPredictionHeadTransform with Bert->Lxmert
class TFLxmertPredictionHeadTransform(tf.keras.layers.Layer):
def __init__(self, config: LxmertConfig, **kwargs):
super().__init__(**kwargs)
self.dense = tf.keras.layers.Dense(
units=config.hidden_size,
kernel_initializer=get_initializer(config.initializer_range),
name="dense",
)
if isinstance(config.hidden_act, str):
self.transform_act_fn = get_tf_activation(config.hidden_act)
else:
self.transform_act_fn = config.hidden_act
self.LayerNorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="LayerNorm")
def call(self, hidden_states: tf.Tensor) -> tf.Tensor:
hidden_states = self.dense(inputs=hidden_states)
hidden_states = self.transform_act_fn(hidden_states)
hidden_states = self.LayerNorm(inputs=hidden_states)
return hidden_states
# Copied from transformers.models.bert.modeling_tf_bert.TFBertLMPredictionHead with Bert->Lxmert
class TFLxmertLMPredictionHead(tf.keras.layers.Layer):
def __init__(self, config: LxmertConfig, input_embeddings: tf.keras.layers.Layer, **kwargs):
super().__init__(**kwargs)
self.vocab_size = config.vocab_size
self.hidden_size = config.hidden_size
self.transform = TFLxmertPredictionHeadTransform(config, name="transform")
# The output weights are the same as the input embeddings, but there is
# an output-only bias for each token.
self.input_embeddings = input_embeddings
def build(self, input_shape: tf.TensorShape):
self.bias = self.add_weight(shape=(self.vocab_size,), initializer="zeros", trainable=True, name="bias")
super().build(input_shape)
def get_output_embeddings(self) -> tf.keras.layers.Layer:
return self.input_embeddings
def set_output_embeddings(self, value: tf.Variable):
self.input_embeddings.weight = value
self.input_embeddings.vocab_size = shape_list(value)[0]
def get_bias(self) -> Dict[str, tf.Variable]:
return {"bias": self.bias}
def set_bias(self, value: tf.Variable):
self.bias = value["bias"]
self.vocab_size = shape_list(value["bias"])[0]
def call(self, hidden_states: tf.Tensor) -> tf.Tensor:
hidden_states = self.transform(hidden_states=hidden_states)
seq_length = shape_list(hidden_states)[1]
hidden_states = tf.reshape(tensor=hidden_states, shape=[-1, self.hidden_size])
hidden_states = tf.matmul(a=hidden_states, b=self.input_embeddings.weight, transpose_b=True)
hidden_states = tf.reshape(tensor=hidden_states, shape=[-1, seq_length, self.vocab_size])
hidden_states = tf.nn.bias_add(value=hidden_states, bias=self.bias)
return hidden_states
# Copied from transformers.models.bert.modeling_tf_bert.TFBertMLMHead with Bert->Lxmert
class TFLxmertMLMHead(tf.keras.layers.Layer):
def __init__(self, config: LxmertConfig, input_embeddings: tf.keras.layers.Layer, **kwargs):
super().__init__(**kwargs)
self.predictions = TFLxmertLMPredictionHead(config, input_embeddings, name="predictions")
def call(self, sequence_output: tf.Tensor) -> tf.Tensor:
prediction_scores = self.predictions(hidden_states=sequence_output)
return prediction_scores
class TFLxmertPreTrainingHeads(tf.keras.layers.Layer):
def __init__(self, config, input_embeddings, **kwargs):
super().__init__(**kwargs)
self.predictions = TFLxmertLMPredictionHead(config, input_embeddings, name="predictions")
self.seq_relationship = tf.keras.layers.Dense(
2,
kernel_initializer=get_initializer(config.initializer_range),
name="seq_relationship",
)
def call(self, sequence_output, pooled_output):
prediction_scores = self.predictions(sequence_output)
seq_relationship_score = self.seq_relationship(pooled_output)
return prediction_scores, seq_relationship_score
class TFLxmertVisualAnswerHead(tf.keras.layers.Layer):
def __init__(self, config, num_labels, **kwargs):
super().__init__(**kwargs)
hid_dim = config.hidden_size
self.dense = tf.keras.layers.Dense(
hid_dim * 2,
kernel_initializer=get_initializer(config.initializer_range),
name="logit_fc_._0",
)
self.activation = get_tf_activation("gelu")
self.layer_norm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_eps, name="logit_fc_._2")
self.dense_1 = tf.keras.layers.Dense(
num_labels,
kernel_initializer=get_initializer(config.initializer_range),
name="logit_fc_._3",
)
def call(self, hidden_states):
hidden_states = self.dense(hidden_states)
hidden_states = self.activation(hidden_states)
hidden_states = self.layer_norm(hidden_states)
hidden_states = self.dense_1(hidden_states)
return hidden_states
class TFLxmertVisualObjHead(tf.keras.layers.Layer):
def __init__(self, config, **kwargs):
super().__init__(**kwargs)
self.transform = TFLxmertPredictionHeadTransform(config, name="transform")
# Decide the use of visual losses
visual_losses = {}
if config.visual_obj_loss:
visual_losses["obj"] = {"shape": (-1,), "num": config.num_object_labels}
if config.visual_attr_loss:
visual_losses["attr"] = {"shape": (-1,), "num": config.num_attr_labels}
if config.visual_obj_loss:
visual_losses["feat"] = {"shape": (-1, 2048), "num": config.visual_feat_dim}
self.visual_losses = visual_losses
# The output weights are the same as the input embeddings, but there is
# an output-only bias for each token.
self.decoder_dict = {
key: tf.keras.layers.Dense(
self.visual_losses[key]["num"],
kernel_initializer=get_initializer(config.initializer_range),
name=f"decoder_dict.{key}",
)
for key in self.visual_losses
}
def call(self, hidden_states):
hidden_states = self.transform(hidden_states)
output = {}
for key in self.visual_losses:
output[key] = self.decoder_dict[key](hidden_states)
return output
@add_start_docstrings("""Lxmert Model with a `language modeling` head on top. """, LXMERT_START_DOCSTRING)
class TFLxmertForPreTraining(TFLxmertPreTrainedModel):
def __init__(self, config, *inputs, **kwargs):
super().__init__(config, *inputs, **kwargs)
self.config = config
self.num_qa_labels = config.num_qa_labels
self.visual_loss_normalizer = config.visual_loss_normalizer
# Use of pretraining tasks
self.task_mask_lm = config.task_mask_lm
self.task_obj_predict = config.task_obj_predict
self.task_matched = config.task_matched
self.task_qa = config.task_qa
# Lxmert backbone
self.lxmert = TFLxmertMainLayer(config, name="lxmert")
# Pre-training heads
self.cls = TFLxmertPreTrainingHeads(config, self.lxmert.embeddings, name="cls")
if self.task_obj_predict:
self.obj_predict_head = TFLxmertVisualObjHead(config, name="obj_predict_head")
if self.task_qa:
self.answer_head = TFLxmertVisualAnswerHead(config, self.num_qa_labels, name="answer_head")
# Loss functions
self.loss_fcts = {
"l2": tf.keras.losses.Huber(delta=1.0, name="huber_loss"),
"visn_ce": tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
"ce": tf.keras.losses.SparseCategoricalCrossentropy(from_logits=True),
}
visual_losses = {}
if config.visual_obj_loss:
visual_losses["obj"] = {
"shape": (-1,),
"num": config.num_object_labels,
"loss": "visn_ce",
}
if config.visual_attr_loss:
visual_losses["attr"] = {
"shape": (-1,),
"num": config.num_attr_labels,
"loss": "visn_ce",
}
if config.visual_obj_loss:
visual_losses["feat"] = {
"shape": (-1, config.visual_feat_dim),
"num": config.visual_feat_dim,
"loss": "l2",
}
self.visual_losses = visual_losses
@property
def dummy_inputs(self):
"""
Dummy inputs to build the network.
Returns:
tf.Tensor with dummy inputs
"""
batch_size = 2
num_visual_features = 10
input_ids = tf.constant([[3, 5, 6], [2, 3, 4]])
visual_feats = tf.random.uniform((batch_size, num_visual_features, self.config.visual_feat_dim))
visual_pos = tf.random.uniform((batch_size, num_visual_features, 4))
if self.config.task_obj_predict:
obj_labels = {}
if self.config.visual_attr_loss and self.config.task_obj_predict:
obj_labels["attr"] = (
tf.ones([batch_size, num_visual_features]),
tf.ones([batch_size, num_visual_features]),
)
if self.config.visual_feat_loss and self.config.task_obj_predict:
obj_labels["feat"] = (
tf.ones([batch_size, num_visual_features, self.config.visual_feat_dim]),
tf.ones([batch_size, num_visual_features]),
)
if self.config.visual_obj_loss and self.config.task_obj_predict:
obj_labels["obj"] = (
tf.ones([batch_size, num_visual_features]),
tf.ones([batch_size, num_visual_features]),
)
return {
**{
"input_ids": input_ids,
"visual_feats": visual_feats,
"visual_pos": visual_pos,
},
**({"obj_labels": obj_labels} if self.config.task_obj_predict else {}),
}
def get_lm_head(self):
return self.cls.predictions
def get_prefix_bias_name(self):
warnings.warn("The method get_prefix_bias_name is deprecated. Please use `get_bias` instead.", FutureWarning)
return self.name + "/" + self.cls.name + "/" + self.cls.predictions.name
@add_start_docstrings_to_model_forward(LXMERT_INPUTS_DOCSTRING)
@replace_return_docstrings(output_type=TFLxmertForPreTrainingOutput, config_class=_CONFIG_FOR_DOC)
def call(
self,
input_ids=None,
visual_feats=None,
visual_pos=None,
attention_mask=None,
visual_attention_mask=None,
token_type_ids=None,
inputs_embeds=None,
masked_lm_labels=None,
obj_labels=None,
matched_label=None,
ans=None,
output_attentions=None,
output_hidden_states=None,
return_dict=None,
training=False,
**kwargs,
):
r"""
masked_lm_labels (`tf.Tensor` of shape `(batch_size, sequence_length)`, *optional*):
Labels for computing the masked language modeling loss. Indices should be in `[-100, 0, ..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are ignored
(masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`
obj_labels: (`Dict[Str: Tuple[tf.Tensor, tf.Tensor]]`, *optional*, defaults to :obj: *None*):
each key is named after each one of the visual losses and each element of the tuple is of the shape
`(batch_size, num_features)` and `(batch_size, num_features, visual_feature_dim)` for each the label id
and the label score respectively
matched_label (`tf.Tensor` of shape `(batch_size,)`, *optional*):
Labels for computing the whether or not the text input matches the image (classification) loss. Input
should be a sequence pair (see `input_ids` docstring) Indices should be in `[0, 1]`:
- 0 indicates that the sentence does not match the image,
- 1 indicates that the sentence does match the image.
ans (`Torch.Tensor` of shape `(batch_size)`, *optional*, defaults to :obj: *None*):
a one hot representation hof the correct answer *optional*
Returns:
"""
inputs = input_processing(
func=self.call,
config=self.config,
input_ids=input_ids,
visual_feats=visual_feats,
visual_pos=visual_pos,
attention_mask=attention_mask,
visual_attention_mask=visual_attention_mask,
token_type_ids=token_type_ids,
inputs_embeds=inputs_embeds,
masked_lm_labels=masked_lm_labels,
obj_labels=obj_labels,
matched_label=matched_label,
ans=ans,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict,
training=training,
kwargs_call=kwargs,
)
lxmert_output = self.lxmert(
input_ids=inputs["input_ids"],
visual_feats=inputs["visual_feats"],
visual_pos=inputs["visual_pos"],
attention_mask=inputs["attention_mask"],
visual_attention_mask=inputs["visual_attention_mask"],
token_type_ids=inputs["token_type_ids"],
inputs_embeds=inputs["inputs_embeds"],
output_attentions=inputs["output_attentions"],
output_hidden_states=inputs["output_hidden_states"],
return_dict=inputs["return_dict"],
training=inputs["training"],
)
lang_output, visual_output, pooled_output = (
lxmert_output[0],
lxmert_output[1],
lxmert_output[2],
)
lang_prediction_scores, cross_relationship_score = self.cls(lang_output, pooled_output)
if self.task_qa:
answer_score = self.answer_head(pooled_output)
else:
answer_score = pooled_output[0][0]
total_loss = (
None
if (
inputs["masked_lm_labels"] is None
and inputs["matched_label"] is None
and inputs["obj_labels"] is None
and inputs["ans"] is None
)
else tf.constant(0.0)
)
losses = ()
if inputs["masked_lm_labels"] is not None and self.task_mask_lm:
masked_lm_loss = self.loss_fcts["ce"](
tf.reshape(inputs["masked_lm_labels"], [-1]),
tf.reshape(lang_prediction_scores, [-1, self.config.vocab_size]),
)
total_loss += masked_lm_loss
losses += (masked_lm_loss,)
if inputs["matched_label"] is not None and self.task_matched:
matched_loss = self.loss_fcts["ce"](
tf.reshape(inputs["matched_label"], [-1]),
tf.reshape(cross_relationship_score, [-1, 2]),
)
total_loss += matched_loss
losses += (matched_loss,)
if inputs["obj_labels"] is not None and self.task_obj_predict:
total_visn_loss = 0.0
visn_prediction_scores_dict = self.obj_predict_head(visual_output)
for key, key_info in self.visual_losses.items():
label, mask_conf = inputs["obj_labels"][key]
output_dim = key_info["num"]
loss_fct_name = key_info["loss"]
label_shape = key_info["shape"]
weight = self.visual_loss_normalizer
visn_loss_fct = self.loss_fcts[loss_fct_name]
visn_prediction_scores = visn_prediction_scores_dict[key]
visn_loss = visn_loss_fct(
tf.reshape(label, label_shape),
tf.reshape(visn_prediction_scores, [-1, output_dim]),
)
if visn_loss.ndim > 1: # Regression Losses
visn_loss = tf.reduce_mean(visn_loss)
visn_loss = tf.reduce_mean(visn_loss * tf.cast(tf.reshape(mask_conf, [-1]), visn_loss.dtype)) * weight
total_visn_loss += visn_loss
losses += (visn_loss,)
total_loss += total_visn_loss
if inputs["ans"] is not None and self.task_qa:
answer_loss = self.loss_fcts["ce"](
tf.reshape(ans, [-1]), tf.reshape(answer_score, [-1, self.num_qa_labels])
)
# exclude "*2" here to match the effect of QA losses.
# Previous: (loss *0) for 6 epochs, (loss *2) for 6 epochs. (Used 10 instead of 6 in EMNLP paper)
# Now : (loss *1) for 12 epochs
#
# * 2 # Multiply by 2 because > half of the data will not have label
total_loss += answer_loss
losses += (answer_loss,)
# return total_loss, tf.stack(losses)[tf.new_axis, ...], answer_score.detach()
if not inputs["return_dict"]:
output = (
lang_prediction_scores,
cross_relationship_score,
answer_score,
) + lxmert_output[3:]
return ((total_loss,) + output) if total_loss is not None else output
return TFLxmertForPreTrainingOutput(
loss=total_loss,
prediction_logits=lang_prediction_scores,
cross_relationship_score=cross_relationship_score,
question_answering_score=answer_score,
language_hidden_states=lxmert_output.language_hidden_states,
vision_hidden_states=lxmert_output.vision_hidden_states,
language_attentions=lxmert_output.language_attentions,
vision_attentions=lxmert_output.vision_attentions,
cross_encoder_attentions=lxmert_output.cross_encoder_attentions,
)
def serving_output(self, output):
l_hs = tf.convert_to_tensor(output.language_hidden_states) if self.config.output_hidden_states else None
v_hs = tf.convert_to_tensor(output.vision_hidden_states) if self.config.output_hidden_states else None
l_attns = tf.convert_to_tensor(output.language_attentions) if self.config.output_attentions else None
v_attns = tf.convert_to_tensor(output.vision_attentions) if self.config.output_attentions else None
c_enc_attns = tf.convert_to_tensor(output.cross_encoder_attentions) if self.config.output_attentions else None
return TFLxmertForPreTrainingOutput(
prediction_logits=output.prediction_logits,
cross_relationship_score=output.cross_relationship_score,
question_answering_score=output.question_answering_score,
language_hidden_states=l_hs,
vision_hidden_states=v_hs,
language_attentions=l_attns,
vision_attentions=v_attns,
cross_encoder_attentions=c_enc_attns,
)