from pathlib import Path
import torch
from torch import nn
from torch.nn.common_types import _size_2_t
from torch.nn.modules.utils import _pair
from torchvision import tv_tensors
from torchvision.transforms import v2
from torch_uncertainty.datamodules import TUDataModule
from torch_uncertainty.datasets.segmentation import Cityscapes
from torch_uncertainty.transforms import RandomRescale
from torch_uncertainty.utils.misc import create_train_val_split
[docs]class CityscapesDataModule(TUDataModule):
num_classes = 19
num_channels = 3
training_task = "segmentation"
mean = (0.485, 0.456, 0.406)
std = (0.229, 0.224, 0.225)
def __init__(
self,
root: str | Path,
batch_size: int,
crop_size: _size_2_t = 1024,
eval_size: _size_2_t = (1024, 2048),
basic_augment: bool = True,
val_split: float | None = None,
num_workers: int = 1,
pin_memory: bool = True,
persistent_workers: bool = True,
) -> None:
r"""DataModule for the Cityscapes dataset.
Args:
root (str or Path): Root directory of the datasets.
batch_size (int): Number of samples per batch.
crop_size (sequence or int, optional): Desired input image and
segmentation mask sizes during training. If :attr:`crop_size` is an
int instead of sequence like :math:`(H, W)`, a square crop
:math:`(\text{size},\text{size})` is made. If provided a sequence
of length :math:`1`, it will be interpreted as
:math:`(\text{size[0]},\text{size[1]})`. Defaults to ``1024``.
eval_size (sequence or int, optional): Desired input image and
segmentation mask sizes during evaluation. If size is an int,
smaller edge of the images will be matched to this number, i.e.,
:math:`\text{height}>\text{width}`, then image will be rescaled to
:math:`(\text{size}\times\text{height}/\text{width},\text{size})`.
Defaults to ``(1024,2048)``.
basic_augment (bool): Whether to apply base augmentations. Defaults to
``True``.
val_split (float or None, optional): Share of training samples to use
for validation. Defaults to ``None``.
num_workers (int, optional): Number of dataloaders to use. Defaults to
``1``.
pin_memory (bool, optional): Whether to pin memory. Defaults to
``True``.
persistent_workers (bool, optional): Whether to use persistent workers.
Defaults to ``True``.
Note:
This datamodule injects the following transforms into the training and
validation/test datasets:
Training transforms:
.. code-block:: python
from torchvision.transforms import v2
v2.Compose([
v2.ToImage(),
RandomRescale(min_scale=0.5, max_scale=2.0, antialias=True),
v2.RandomCrop(size=crop_size, pad_if_needed=True),
v2.ColorJitter(brightness=0.5, contrast=0.5, saturation=0.5),
v2.RandomHorizontalFlip(),
v2.ToDtype({
tv_tensors.Image: torch.float32,
tv_tensors.Mask: torch.int64,
"others": None
}, scale=True),
v2.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
])
Validation/Test transforms:
.. code-block:: python
from torchvision.transforms import v2
v2.Compose([
v2.ToImage(),
v2.Resize(size=eval_size, antialias=True),
v2.ToDtype({
tv_tensors.Image: torch.float32,
tv_tensors.Mask: torch.int64,
"others": None
}, scale=True),
v2.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
])
This behavior can be modified by overriding ``self.train_transform``
and ``self.test_transform`` after initialization.
"""
super().__init__(
root=root,
batch_size=batch_size,
val_split=val_split,
num_workers=num_workers,
pin_memory=pin_memory,
persistent_workers=persistent_workers,
)
self.dataset = Cityscapes
self.mode = "fine"
self.crop_size = _pair(crop_size)
self.eval_size = _pair(eval_size)
if basic_augment:
basic_transform = v2.Compose(
[
RandomRescale(min_scale=0.5, max_scale=2.0, antialias=True),
v2.RandomCrop(
size=self.crop_size,
pad_if_needed=True,
fill={tv_tensors.Image: 0, tv_tensors.Mask: 255},
),
v2.ColorJitter(
brightness=0.5, contrast=0.5, saturation=0.5
),
v2.RandomHorizontalFlip(),
]
)
else:
basic_transform = nn.Identity()
self.train_transform = v2.Compose(
[
v2.ToImage(),
basic_transform,
v2.ToDtype(
dtype={
tv_tensors.Image: torch.float32,
tv_tensors.Mask: torch.int64,
"others": None,
},
scale=True,
),
v2.Normalize(mean=self.mean, std=self.std),
]
)
self.test_transform = v2.Compose(
[
v2.ToImage(),
v2.Resize(size=self.eval_size, antialias=True),
v2.ToDtype(
dtype={
tv_tensors.Image: torch.float32,
tv_tensors.Mask: torch.int64,
"others": None,
},
scale=True,
),
v2.Normalize(mean=self.mean, std=self.std),
]
)
def prepare_data(self) -> None: # coverage: ignore
self.dataset(root=self.root, split="train", mode=self.mode)
def setup(self, stage: str | None = None) -> None:
if stage == "fit" or stage is None:
full = self.dataset(
root=self.root,
split="train",
mode=self.mode,
target_type="semantic",
transforms=self.train_transform,
)
if self.val_split is not None:
self.train, self.val = create_train_val_split(
full,
self.val_split,
self.test_transform,
)
else:
self.train = full
self.val = self.dataset(
root=self.root,
split="val",
mode=self.mode,
target_type="semantic",
transforms=self.test_transform,
)
if stage == "test" or stage is None:
self.test = self.dataset(
root=self.root,
split="val",
mode=self.mode,
target_type="semantic",
transforms=self.test_transform,
)
if stage not in ["fit", "test", None]:
raise ValueError(f"Stage {stage} is not supported.")
