-
Notifications
You must be signed in to change notification settings - Fork 25.8k
/
image_processing_layoutlmv3.py
387 lines (347 loc) · 18.4 KB
/
image_processing_layoutlmv3.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
# coding=utf-8
# Copyright 2022 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.
"""Image processor class for LayoutLMv3."""
from typing import Dict, Iterable, Optional, Union
import numpy as np
from ...image_processing_utils import BaseImageProcessor, BatchFeature, get_size_dict
from ...image_transforms import resize, to_channel_dimension_format, to_pil_image
from ...image_utils import (
IMAGENET_STANDARD_MEAN,
IMAGENET_STANDARD_STD,
ChannelDimension,
ImageInput,
PILImageResampling,
infer_channel_dimension_format,
is_scaled_image,
make_list_of_images,
to_numpy_array,
valid_images,
validate_kwargs,
validate_preprocess_arguments,
)
from ...utils import TensorType, is_pytesseract_available, is_vision_available, logging, requires_backends
if is_vision_available():
import PIL
# soft dependency
if is_pytesseract_available():
import pytesseract
logger = logging.get_logger(__name__)
def normalize_box(box, width, height):
return [
int(1000 * (box[0] / width)),
int(1000 * (box[1] / height)),
int(1000 * (box[2] / width)),
int(1000 * (box[3] / height)),
]
def apply_tesseract(
image: np.ndarray,
lang: Optional[str],
tesseract_config: Optional[str],
input_data_format: Optional[Union[ChannelDimension, str]] = None,
):
"""Applies Tesseract OCR on a document image, and returns recognized words + normalized bounding boxes."""
# apply OCR
pil_image = to_pil_image(image, input_data_format=input_data_format)
image_width, image_height = pil_image.size
data = pytesseract.image_to_data(pil_image, lang=lang, output_type="dict", config=tesseract_config)
words, left, top, width, height = data["text"], data["left"], data["top"], data["width"], data["height"]
# filter empty words and corresponding coordinates
irrelevant_indices = [idx for idx, word in enumerate(words) if not word.strip()]
words = [word for idx, word in enumerate(words) if idx not in irrelevant_indices]
left = [coord for idx, coord in enumerate(left) if idx not in irrelevant_indices]
top = [coord for idx, coord in enumerate(top) if idx not in irrelevant_indices]
width = [coord for idx, coord in enumerate(width) if idx not in irrelevant_indices]
height = [coord for idx, coord in enumerate(height) if idx not in irrelevant_indices]
# turn coordinates into (left, top, left+width, top+height) format
actual_boxes = []
for x, y, w, h in zip(left, top, width, height):
actual_box = [x, y, x + w, y + h]
actual_boxes.append(actual_box)
# finally, normalize the bounding boxes
normalized_boxes = []
for box in actual_boxes:
normalized_boxes.append(normalize_box(box, image_width, image_height))
assert len(words) == len(normalized_boxes), "Not as many words as there are bounding boxes"
return words, normalized_boxes
class LayoutLMv3ImageProcessor(BaseImageProcessor):
r"""
Constructs a LayoutLMv3 image processor.
Args:
do_resize (`bool`, *optional*, defaults to `True`):
Whether to resize the image's (height, width) dimensions to `(size["height"], size["width"])`. Can be
overridden by `do_resize` in `preprocess`.
size (`Dict[str, int]` *optional*, defaults to `{"height": 224, "width": 224}`):
Size of the image after resizing. Can be overridden by `size` in `preprocess`.
resample (`PILImageResampling`, *optional*, defaults to `PILImageResampling.BILINEAR`):
Resampling filter to use if resizing the image. Can be overridden by `resample` in `preprocess`.
do_rescale (`bool`, *optional*, defaults to `True`):
Whether to rescale the image's pixel values by the specified `rescale_value`. Can be overridden by
`do_rescale` in `preprocess`.
rescale_factor (`float`, *optional*, defaults to 1 / 255):
Value by which the image's pixel values are rescaled. Can be overridden by `rescale_factor` in
`preprocess`.
do_normalize (`bool`, *optional*, defaults to `True`):
Whether to normalize the image. Can be overridden by the `do_normalize` parameter in the `preprocess`
method.
image_mean (`Iterable[float]` or `float`, *optional*, defaults to `IMAGENET_STANDARD_MEAN`):
Mean to use if normalizing the image. This is a float or list of floats the length of the number of
channels in the image. Can be overridden by the `image_mean` parameter in the `preprocess` method.
image_std (`Iterable[float]` or `float`, *optional*, defaults to `IMAGENET_STANDARD_STD`):
Standard deviation to use if normalizing the image. This is a float or list of floats the length of the
number of channels in the image. Can be overridden by the `image_std` parameter in the `preprocess` method.
apply_ocr (`bool`, *optional*, defaults to `True`):
Whether to apply the Tesseract OCR engine to get words + normalized bounding boxes. Can be overridden by
the `apply_ocr` parameter in the `preprocess` method.
ocr_lang (`str`, *optional*):
The language, specified by its ISO code, to be used by the Tesseract OCR engine. By default, English is
used. Can be overridden by the `ocr_lang` parameter in the `preprocess` method.
tesseract_config (`str`, *optional*):
Any additional custom configuration flags that are forwarded to the `config` parameter when calling
Tesseract. For example: '--psm 6'. Can be overridden by the `tesseract_config` parameter in the
`preprocess` method.
"""
model_input_names = ["pixel_values"]
def __init__(
self,
do_resize: bool = True,
size: Dict[str, int] = None,
resample: PILImageResampling = PILImageResampling.BILINEAR,
do_rescale: bool = True,
rescale_value: float = 1 / 255,
do_normalize: bool = True,
image_mean: Union[float, Iterable[float]] = None,
image_std: Union[float, Iterable[float]] = None,
apply_ocr: bool = True,
ocr_lang: Optional[str] = None,
tesseract_config: Optional[str] = "",
**kwargs,
) -> None:
super().__init__(**kwargs)
size = size if size is not None else {"height": 224, "width": 224}
size = get_size_dict(size)
self.do_resize = do_resize
self.size = size
self.resample = resample
self.do_rescale = do_rescale
self.rescale_factor = rescale_value
self.do_normalize = do_normalize
self.image_mean = image_mean if image_mean is not None else IMAGENET_STANDARD_MEAN
self.image_std = image_std if image_std is not None else IMAGENET_STANDARD_STD
self.apply_ocr = apply_ocr
self.ocr_lang = ocr_lang
self.tesseract_config = tesseract_config
self._valid_processor_keys = [
"images",
"do_resize",
"size",
"resample",
"do_rescale",
"rescale_factor",
"do_normalize",
"image_mean",
"image_std",
"apply_ocr",
"ocr_lang",
"tesseract_config",
"return_tensors",
"data_format",
"input_data_format",
]
# Copied from transformers.models.vit.image_processing_vit.ViTImageProcessor.resize
def resize(
self,
image: np.ndarray,
size: Dict[str, int],
resample: PILImageResampling = PILImageResampling.BILINEAR,
data_format: Optional[Union[str, ChannelDimension]] = None,
input_data_format: Optional[Union[str, ChannelDimension]] = None,
**kwargs,
) -> np.ndarray:
"""
Resize an image to `(size["height"], size["width"])`.
Args:
image (`np.ndarray`):
Image to resize.
size (`Dict[str, int]`):
Dictionary in the format `{"height": int, "width": int}` specifying the size of the output image.
resample (`PILImageResampling`, *optional*, defaults to `PILImageResampling.BILINEAR`):
`PILImageResampling` filter to use when resizing the image e.g. `PILImageResampling.BILINEAR`.
data_format (`ChannelDimension` or `str`, *optional*):
The channel dimension format for the output image. If unset, the channel dimension format of the input
image is used. Can be one of:
- `"channels_first"` or `ChannelDimension.FIRST`: image in (num_channels, height, width) format.
- `"channels_last"` or `ChannelDimension.LAST`: image in (height, width, num_channels) format.
- `"none"` or `ChannelDimension.NONE`: image in (height, width) format.
input_data_format (`ChannelDimension` or `str`, *optional*):
The channel dimension format for the input image. If unset, the channel dimension format is inferred
from the input image. Can be one of:
- `"channels_first"` or `ChannelDimension.FIRST`: image in (num_channels, height, width) format.
- `"channels_last"` or `ChannelDimension.LAST`: image in (height, width, num_channels) format.
- `"none"` or `ChannelDimension.NONE`: image in (height, width) format.
Returns:
`np.ndarray`: The resized image.
"""
size = get_size_dict(size)
if "height" not in size or "width" not in size:
raise ValueError(f"The `size` dictionary must contain the keys `height` and `width`. Got {size.keys()}")
output_size = (size["height"], size["width"])
return resize(
image,
size=output_size,
resample=resample,
data_format=data_format,
input_data_format=input_data_format,
**kwargs,
)
def preprocess(
self,
images: ImageInput,
do_resize: bool = None,
size: Dict[str, int] = None,
resample=None,
do_rescale: bool = None,
rescale_factor: float = None,
do_normalize: bool = None,
image_mean: Union[float, Iterable[float]] = None,
image_std: Union[float, Iterable[float]] = None,
apply_ocr: bool = None,
ocr_lang: Optional[str] = None,
tesseract_config: Optional[str] = None,
return_tensors: Optional[Union[str, TensorType]] = None,
data_format: ChannelDimension = ChannelDimension.FIRST,
input_data_format: Optional[Union[str, ChannelDimension]] = None,
**kwargs,
) -> PIL.Image.Image:
"""
Preprocess an image or batch of images.
Args:
images (`ImageInput`):
Image to preprocess. Expects a single or batch of images with pixel values ranging from 0 to 255. If
passing in images with pixel values between 0 and 1, set `do_rescale=False`.
do_resize (`bool`, *optional*, defaults to `self.do_resize`):
Whether to resize the image.
size (`Dict[str, int]`, *optional*, defaults to `self.size`):
Desired size of the output image after applying `resize`.
resample (`int`, *optional*, defaults to `self.resample`):
Resampling filter to use if resizing the image. This can be one of the `PILImageResampling` filters.
Only has an effect if `do_resize` is set to `True`.
do_rescale (`bool`, *optional*, defaults to `self.do_rescale`):
Whether to rescale the image pixel values between [0, 1].
rescale_factor (`float`, *optional*, defaults to `self.rescale_factor`):
Rescale factor to apply to the image pixel values. Only has an effect if `do_rescale` is set to `True`.
do_normalize (`bool`, *optional*, defaults to `self.do_normalize`):
Whether to normalize the image.
image_mean (`float` or `Iterable[float]`, *optional*, defaults to `self.image_mean`):
Mean values to be used for normalization. Only has an effect if `do_normalize` is set to `True`.
image_std (`float` or `Iterable[float]`, *optional*, defaults to `self.image_std`):
Standard deviation values to be used for normalization. Only has an effect if `do_normalize` is set to
`True`.
apply_ocr (`bool`, *optional*, defaults to `self.apply_ocr`):
Whether to apply the Tesseract OCR engine to get words + normalized bounding boxes.
ocr_lang (`str`, *optional*, defaults to `self.ocr_lang`):
The language, specified by its ISO code, to be used by the Tesseract OCR engine. By default, English is
used.
tesseract_config (`str`, *optional*, defaults to `self.tesseract_config`):
Any additional custom configuration flags that are forwarded to the `config` parameter when calling
Tesseract.
return_tensors (`str` or `TensorType`, *optional*):
The type of tensors to return. Can be one of:
- Unset: Return a list of `np.ndarray`.
- `TensorType.TENSORFLOW` or `'tf'`: Return a batch of type `tf.Tensor`.
- `TensorType.PYTORCH` or `'pt'`: Return a batch of type `torch.Tensor`.
- `TensorType.NUMPY` or `'np'`: Return a batch of type `np.ndarray`.
- `TensorType.JAX` or `'jax'`: Return a batch of type `jax.numpy.ndarray`.
data_format (`ChannelDimension` or `str`, *optional*, defaults to `ChannelDimension.FIRST`):
The channel dimension format for the output image. Can be one of:
- `ChannelDimension.FIRST`: image in (num_channels, height, width) format.
- `ChannelDimension.LAST`: image in (height, width, num_channels) format.
input_data_format (`ChannelDimension` or `str`, *optional*):
The channel dimension format for the input image. If unset, the channel dimension format is inferred
from the input image. Can be one of:
- `"channels_first"` or `ChannelDimension.FIRST`: image in (num_channels, height, width) format.
- `"channels_last"` or `ChannelDimension.LAST`: image in (height, width, num_channels) format.
- `"none"` or `ChannelDimension.NONE`: image in (height, width) format.
"""
do_resize = do_resize if do_resize is not None else self.do_resize
size = size if size is not None else self.size
size = get_size_dict(size)
resample = resample if resample is not None else self.resample
do_rescale = do_rescale if do_rescale is not None else self.do_rescale
rescale_factor = rescale_factor if rescale_factor is not None else self.rescale_factor
do_normalize = do_normalize if do_normalize is not None else self.do_normalize
image_mean = image_mean if image_mean is not None else self.image_mean
image_std = image_std if image_std is not None else self.image_std
apply_ocr = apply_ocr if apply_ocr is not None else self.apply_ocr
ocr_lang = ocr_lang if ocr_lang is not None else self.ocr_lang
tesseract_config = tesseract_config if tesseract_config is not None else self.tesseract_config
images = make_list_of_images(images)
validate_kwargs(captured_kwargs=kwargs.keys(), valid_processor_keys=self._valid_processor_keys)
if not valid_images(images):
raise ValueError(
"Invalid image type. Must be of type PIL.Image.Image, numpy.ndarray, "
"torch.Tensor, tf.Tensor or jax.ndarray."
)
validate_preprocess_arguments(
do_rescale=do_rescale,
rescale_factor=rescale_factor,
do_normalize=do_normalize,
image_mean=image_mean,
image_std=image_std,
do_resize=do_resize,
size=size,
resample=resample,
)
# All transformations expect numpy arrays.
images = [to_numpy_array(image) for image in images]
if is_scaled_image(images[0]) and do_rescale:
logger.warning_once(
"It looks like you are trying to rescale already rescaled images. If the input"
" images have pixel values between 0 and 1, set `do_rescale=False` to avoid rescaling them again."
)
if input_data_format is None:
# We assume that all images have the same channel dimension format.
input_data_format = infer_channel_dimension_format(images[0])
# Tesseract OCR to get words + normalized bounding boxes
if apply_ocr:
requires_backends(self, "pytesseract")
words_batch = []
boxes_batch = []
for image in images:
words, boxes = apply_tesseract(image, ocr_lang, tesseract_config, input_data_format=input_data_format)
words_batch.append(words)
boxes_batch.append(boxes)
if do_resize:
images = [
self.resize(image=image, size=size, resample=resample, input_data_format=input_data_format)
for image in images
]
if do_rescale:
images = [
self.rescale(image=image, scale=rescale_factor, input_data_format=input_data_format)
for image in images
]
if do_normalize:
images = [
self.normalize(image=image, mean=image_mean, std=image_std, input_data_format=input_data_format)
for image in images
]
images = [
to_channel_dimension_format(image, data_format, input_channel_dim=input_data_format) for image in images
]
data = BatchFeature(data={"pixel_values": images}, tensor_type=return_tensors)
if apply_ocr:
data["words"] = words_batch
data["boxes"] = boxes_batch
return data