You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

125 lines
5.2 KiB

# Copyright 2021 The HuggingFace Inc. team.
#
# 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.
"""
Processor class for LayoutLMv2.
"""
from ...processing_utils import ProcessorMixin
from ...tokenization_utils_base import BatchEncoding, PaddingStrategy, PreTokenizedInput, TextInput, TruncationStrategy
from ...utils import TensorType, auto_docstring
@auto_docstring
class LayoutLMv2Processor(ProcessorMixin):
def __init__(self, image_processor=None, tokenizer=None, **kwargs):
super().__init__(image_processor, tokenizer)
@auto_docstring
def __call__(
self,
images,
text: TextInput | PreTokenizedInput | list[TextInput] | list[PreTokenizedInput] = None,
text_pair: PreTokenizedInput | list[PreTokenizedInput] | None = None,
boxes: list[list[int]] | list[list[list[int]]] | None = None,
word_labels: list[int] | list[list[int]] | None = None,
add_special_tokens: bool = True,
padding: bool | str | PaddingStrategy = False,
truncation: bool | str | TruncationStrategy = False,
max_length: int | None = None,
stride: int = 0,
pad_to_multiple_of: int | None = None,
return_token_type_ids: bool | None = None,
return_attention_mask: bool | None = None,
return_overflowing_tokens: bool = False,
return_special_tokens_mask: bool = False,
return_offsets_mapping: bool = False,
return_length: bool = False,
verbose: bool = True,
return_tensors: str | TensorType | None = None,
**kwargs,
) -> BatchEncoding:
# verify input
if self.image_processor.apply_ocr and (boxes is not None):
raise ValueError(
"You cannot provide bounding boxes if you initialized the image processor with apply_ocr set to True."
)
if self.image_processor.apply_ocr and (word_labels is not None):
raise ValueError(
"You cannot provide word labels if you initialized the image processor with apply_ocr set to True."
)
if return_overflowing_tokens is True and return_offsets_mapping is False:
raise ValueError("You cannot return overflowing tokens without returning the offsets mapping.")
# first, apply the image processor
features = self.image_processor(images=images, return_tensors=return_tensors)
# second, apply the tokenizer
if text is not None and self.image_processor.apply_ocr and text_pair is None:
if isinstance(text, str):
text = [text] # add batch dimension (as the image processor always adds a batch dimension)
text_pair = features["words"]
encoded_inputs = self.tokenizer(
text=text if text is not None else features["words"],
text_pair=text_pair if text_pair is not None else None,
boxes=boxes if boxes is not None else features["boxes"],
word_labels=word_labels,
add_special_tokens=add_special_tokens,
padding=padding,
truncation=truncation,
max_length=max_length,
stride=stride,
pad_to_multiple_of=pad_to_multiple_of,
return_token_type_ids=return_token_type_ids,
return_attention_mask=return_attention_mask,
return_overflowing_tokens=return_overflowing_tokens,
return_special_tokens_mask=return_special_tokens_mask,
return_offsets_mapping=return_offsets_mapping,
return_length=return_length,
verbose=verbose,
return_tensors=return_tensors,
**kwargs,
)
# add pixel values
images = features.pop("pixel_values")
if return_overflowing_tokens is True:
images = self.get_overflowing_images(images, encoded_inputs["overflow_to_sample_mapping"])
encoded_inputs["image"] = images
return encoded_inputs
def get_overflowing_images(self, images, overflow_to_sample_mapping):
# in case there's an overflow, ensure each `input_ids` sample is mapped to its corresponding image
images_with_overflow = []
for sample_idx in overflow_to_sample_mapping:
images_with_overflow.append(images[sample_idx])
if len(images_with_overflow) != len(overflow_to_sample_mapping):
raise ValueError(
"Expected length of images to be the same as the length of `overflow_to_sample_mapping`, but got"
f" {len(images_with_overflow)} and {len(overflow_to_sample_mapping)}"
)
return images_with_overflow
@property
def model_input_names(self):
return ["input_ids", "bbox", "token_type_ids", "attention_mask", "image"]
__all__ = ["LayoutLMv2Processor"]