Source code for torchgeo.datamodules.chesapeake

# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License.

"""Chesapeake Bay High-Resolution Land Cover Project datamodule."""

from typing import Any, Dict, List

import kornia.augmentation as K
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from torch import Tensor

from ..datasets import ChesapeakeCVPR
from ..samplers import GridGeoSampler, RandomBatchGeoSampler
from ..transforms import AugmentationSequential
from .geo import GeoDataModule

class _Transform(nn.Module):
    """Version of AugmentationSequential designed for samples, not batches."""

    def __init__(self, aug: nn.Module) -> None:
        """Initialize a new _Transform instance.

            aug: Augmentation to apply.
        self.aug = aug

    def forward(self, sample: Dict[str, Any]) -> Dict[str, Any]:
        """Apply the augmentation.

            sample: Input sample.

            Augmented sample.
        for key in ["image", "mask"]:
            dtype = sample[key].dtype
            # All inputs must be float
            sample[key] = sample[key].float()
            sample[key] = self.aug(sample[key])
            sample[key] = sample[key].to(dtype)
            # Kornia adds batch dimension
            sample[key] = rearrange(sample[key], "() c h w -> c h w")
        return sample

[docs]class ChesapeakeCVPRDataModule(GeoDataModule): """LightningDataModule implementation for the Chesapeake CVPR Land Cover dataset. Uses the random splits defined per state to partition tiles into train, val, and test sets. """
[docs] def __init__( self, train_splits: List[str], val_splits: List[str], test_splits: List[str], batch_size: int = 64, patch_size: int = 256, length: int = 1000, num_workers: int = 0, class_set: int = 7, use_prior_labels: bool = False, prior_smoothing_constant: float = 1e-4, **kwargs: Any, ) -> None: """Initialize a new ChesapeakeCVPRDataModule instance. Args: train_splits: Splits used to train the model, e.g., ["ny-train"]. val_splits: Splits used to validate the model, e.g., ["ny-val"]. test_splits: Splits used to test the model, e.g., ["ny-test"]. batch_size: Size of each mini-batch. patch_size: Size of each patch, either ``size`` or ``(height, width)``. Should be a multiple of 32 for most segmentation architectures. length: Length of each training epoch. num_workers: Number of workers for parallel data loading. class_set: The high-resolution land cover class set to use (5 or 7). use_prior_labels: Flag for using a prior over high-resolution classes instead of the high-resolution labels themselves. prior_smoothing_constant: Additive smoothing to add when using prior labels. **kwargs: Additional keyword arguments passed to :class:`~torchgeo.datasets.ChesapeakeCVPR`. Raises: ValueError: If ``use_prior_labels=True`` is used with ``class_set=7``. """ # This is a rough estimate of how large of a patch we will need to sample in # EPSG:3857 in order to guarantee a large enough patch in the local CRS. self.original_patch_size = patch_size * 2 kwargs["transforms"] = _Transform(K.CenterCrop(patch_size)) super().__init__( ChesapeakeCVPR, batch_size, patch_size, length, num_workers, **kwargs ) assert class_set in [5, 7] if use_prior_labels and class_set == 7: raise ValueError( "The pre-generated prior labels are only valid for the 5" + " class set of labels" ) self.train_splits = train_splits self.val_splits = val_splits self.test_splits = test_splits self.class_set = class_set self.use_prior_labels = use_prior_labels self.prior_smoothing_constant = prior_smoothing_constant if self.use_prior_labels: self.layers = [ "naip-new", "prior_from_cooccurrences_101_31_no_osm_no_buildings", ] else: self.layers = ["naip-new", "lc"] self.aug = AugmentationSequential( K.Normalize(mean=self.mean, std=self.std), data_keys=["image", "mask"] )
[docs] def setup(self, stage: str) -> None: """Set up datasets and samplers. Args: stage: Either 'fit', 'validate', 'test', or 'predict'. """ if stage in ["fit"]: self.train_dataset = ChesapeakeCVPR( splits=self.train_splits, layers=self.layers, **self.kwargs ) self.train_batch_sampler = RandomBatchGeoSampler( self.train_dataset, self.original_patch_size, self.batch_size, self.length, ) if stage in ["fit", "validate"]: self.val_dataset = ChesapeakeCVPR( splits=self.val_splits, layers=self.layers, **self.kwargs ) self.val_sampler = GridGeoSampler( self.val_dataset, self.original_patch_size, self.original_patch_size ) if stage in ["test"]: self.test_dataset = ChesapeakeCVPR( splits=self.test_splits, layers=self.layers, **self.kwargs ) self.test_sampler = GridGeoSampler( self.test_dataset, self.original_patch_size, self.original_patch_size )
[docs] def on_after_batch_transfer( self, batch: Dict[str, Tensor], dataloader_idx: int ) -> Dict[str, Tensor]: """Apply batch augmentations to the batch after it is transferred to the device. Args: batch: A batch of data that needs to be altered or augmented. dataloader_idx: The index of the dataloader to which the batch belongs. Returns: A batch of data. """ if self.use_prior_labels: batch["mask"] = F.normalize(batch["mask"].float(), p=1, dim=1) batch["mask"] = F.normalize( batch["mask"] + self.prior_smoothing_constant, p=1, dim=1 ).long() else: if self.class_set == 5: batch["mask"][batch["mask"] == 5] = 4 batch["mask"][batch["mask"] == 6] = 4 return super().on_after_batch_transfer(batch, dataloader_idx)

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