/usr/local/lib/python3.6/site-packages/transformers/models/vit
Edit: /usr/local/lib/python3.6/site-packages/transformers/models/vit/feature_extraction_vit.py (6307B)
# coding=utf-8
# Copyright 2021 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.
"""Feature extractor class for ViT."""
from typing import Optional, Union
import numpy as np
from PIL import Image
from ...feature_extraction_utils import BatchFeature, FeatureExtractionMixin
from ...image_utils import (
IMAGENET_STANDARD_MEAN,
IMAGENET_STANDARD_STD,
ImageFeatureExtractionMixin,
ImageInput,
is_torch_tensor,
)
from ...utils import TensorType, logging
logger = logging.get_logger(__name__)
class ViTFeatureExtractor(FeatureExtractionMixin, ImageFeatureExtractionMixin):
r"""
Constructs a ViT feature extractor.
This feature extractor inherits from [`FeatureExtractionMixin`] which contains most of the main methods. Users
should refer to this superclass for more information regarding those methods.
Args:
do_resize (`bool`, *optional*, defaults to `True`):
Whether to resize the input to a certain `size`.
size (`int` or `Tuple(int)`, *optional*, defaults to 224):
Resize the input to the given size. If a tuple is provided, it should be (width, height). If only an
integer is provided, then the input will be resized to (size, size). Only has an effect if `do_resize` is
set to `True`.
resample (`int`, *optional*, defaults to `PIL.Image.BILINEAR`):
An optional resampling filter. This can be one of `PIL.Image.NEAREST`, `PIL.Image.BOX`,
`PIL.Image.BILINEAR`, `PIL.Image.HAMMING`, `PIL.Image.BICUBIC` or `PIL.Image.LANCZOS`. Only has an effect
if `do_resize` is set to `True`.
do_normalize (`bool`, *optional*, defaults to `True`):
Whether or not to normalize the input with mean and standard deviation.
image_mean (`List[int]`, defaults to `[0.5, 0.5, 0.5]`):
The sequence of means for each channel, to be used when normalizing images.
image_std (`List[int]`, defaults to `[0.5, 0.5, 0.5]`):
The sequence of standard deviations for each channel, to be used when normalizing images.
"""
model_input_names = ["pixel_values"]
def __init__(
self,
do_resize=True,
size=224,
resample=Image.BILINEAR,
do_normalize=True,
image_mean=None,
image_std=None,
**kwargs
):
super().__init__(**kwargs)
self.do_resize = do_resize
self.size = size
self.resample = resample
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
def __call__(
self, images: ImageInput, return_tensors: Optional[Union[str, TensorType]] = None, **kwargs
) -> BatchFeature:
"""
Main method to prepare for the model one or several image(s).
NumPy arrays and PyTorch tensors are converted to PIL images when resizing, so the most efficient is to pass
PIL images.
Args:
images (`PIL.Image.Image`, `np.ndarray`, `torch.Tensor`, `List[PIL.Image.Image]`, `List[np.ndarray]`, `List[torch.Tensor]`):
The image or batch of images to be prepared. Each image can be a PIL image, NumPy array or PyTorch
tensor. In case of a NumPy array/PyTorch tensor, each image should be of shape (C, H, W), where C is a
number of channels, H and W are image height and width.
return_tensors (`str` or [`~utils.TensorType`], *optional*, defaults to `'np'`):
If set, will return tensors of a particular framework. Acceptable values are:
- `'tf'`: Return TensorFlow `tf.constant` objects.
- `'pt'`: Return PyTorch `torch.Tensor` objects.
- `'np'`: Return NumPy `np.ndarray` objects.
- `'jax'`: Return JAX `jnp.ndarray` objects.
Returns:
[`BatchFeature`]: A [`BatchFeature`] with the following fields:
- **pixel_values** -- Pixel values to be fed to a model, of shape (batch_size, num_channels, height,
width).
"""
# Input type checking for clearer error
valid_images = False
# Check that images has a valid type
if isinstance(images, (Image.Image, np.ndarray)) or is_torch_tensor(images):
valid_images = True
elif isinstance(images, (list, tuple)):
if len(images) == 0 or isinstance(images[0], (Image.Image, np.ndarray)) or is_torch_tensor(images[0]):
valid_images = True
if not valid_images:
raise ValueError(
"Images must of type `PIL.Image.Image`, `np.ndarray` or `torch.Tensor` (single example), "
"`List[PIL.Image.Image]`, `List[np.ndarray]` or `List[torch.Tensor]` (batch of examples)."
)
is_batched = bool(
isinstance(images, (list, tuple))
and (isinstance(images[0], (Image.Image, np.ndarray)) or is_torch_tensor(images[0]))
)
if not is_batched:
images = [images]
# transformations (resizing + normalization)
if self.do_resize and self.size is not None:
images = [self.resize(image=image, size=self.size, resample=self.resample) for image in images]
if self.do_normalize:
images = [self.normalize(image=image, mean=self.image_mean, std=self.image_std) for image in images]
# return as BatchFeature
data = {"pixel_values": images}
encoded_inputs = BatchFeature(data=data, tensor_type=return_tensors)
return encoded_inputs