Kitti Datamodule (#248)

* kitti dataset

* kitti dataset

* kitti dm

* kitti dm

* imports

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

* kitti

pl_bolts/datamodules/__init__.py

@@ -18,5 +18,8 @@
     from pl_bolts.datamodules.ssl_imagenet_datamodule import SSLImagenetDataModule
     from pl_bolts.datamodules.stl10_datamodule import STL10DataModule
     from pl_bolts.datamodules.vocdetection_datamodule import VOCDetectionDataModule
+
+    from pl_bolts.datamodules.kitti_dataset import KittiDataset
+    from pl_bolts.datamodules.kitti_datamodule import KittiDataModule
 except ImportError:
     pass

pl_bolts/datamodules/kitti_datamodule.py

@@ -0,0 +1,99 @@
+import os
+import torch
+
+from pytorch_lightning import LightningDataModule
+from pl_bolts.datamodules.kitti_dataset import KittiDataset
+
+from torch.utils.data import DataLoader
+import torchvision.transforms as transforms
+from torch.utils.data.dataset import random_split
+
+
+class KittiDataModule(LightningDataModule):
+
+    name = 'kitti'
+
+    def __init__(
+            self,
+            data_dir: str,
+            val_split: float = 0.2,
+            test_split: float = 0.1,
+            num_workers: int = 16,
+            batch_size: int = 32,
+            seed: int = 42,
+            *args,
+            **kwargs,
+    ):
+        """
+        Kitti train, validation and test dataloaders.
+
+        Note: You need to have downloaded the Kitti dataset first and provide the path to where it is saved.
+        You can download the dataset here: http://www.cvlibs.net/datasets/kitti/eval_semseg.php?benchmark=semantics2015
+
+        Specs:
+            - 200 samples
+            - Each image is (3 x 1242 x 376)
+
+        In total there are 34 classes but some of these are not useful so by default we use only 19 of the classes
+        specified by the `valid_labels` parameter.
+
+        Example::
+
+            from pl_bolts.datamodules import KittiDataModule
+
+            dm = KittiDataModule(PATH)
+            model = LitModel()
+
+            Trainer().fit(model, dm)
+
+        Args::
+            data_dir: where to load the data from path, i.e. '/path/to/folder/with/data_semantics/'
+            val_split: size of validation test (default 0.2)
+            test_split: size of test set (default 0.1)
+            num_workers: how many workers to use for loading data
+            batch_size: the batch size
+            seed: random seed to be used for train/val/test splits
+        """
+        super().__init__(*args, **kwargs)
+        self.data_dir = data_dir if data_dir is not None else os.getcwd()
+        self.batch_size = batch_size
+        self.num_workers = num_workers
+        self.seed = seed
+
+        self.default_transforms = transforms.Compose([
+            transforms.ToTensor(),
+            transforms.Normalize(mean=[0.35675976, 0.37380189, 0.3764753],
+                                 std=[0.32064945, 0.32098866, 0.32325324])
+        ])
+
+        # split into train, val, test
+        kitti_dataset = KittiDataset(self.data_dir, transform=self.default_transforms)
+
+        val_len = round(val_split * len(kitti_dataset))
+        test_len = round(test_split * len(kitti_dataset))
+        train_len = len(kitti_dataset) - val_len - test_len
+
+        self.trainset, self.valset, self.testset = random_split(kitti_dataset,
+                                                                lengths=[train_len, val_len, test_len],
+                                                                generator=torch.Generator().manual_seed(self.seed))
+
+    def train_dataloader(self):
+        loader = DataLoader(self.trainset,
+                            batch_size=self.batch_size,
+                            shuffle=True,
+                            num_workers=self.num_workers)
+        return loader
+
+    def val_dataloader(self):
+        loader = DataLoader(self.valset,
+                            batch_size=self.batch_size,
+                            shuffle=False,
+                            num_workers=self.num_workers)
+        return loader
+
+    def test_dataloader(self):
+        loader = DataLoader(self.testset,
+                            batch_size=self.batch_size,
+                            shuffle=False,
+                            num_workers=self.num_workers)
+        return loader

pl_bolts/datamodules/kitti_dataset.py

@@ -0,0 +1,92 @@
+import os
+import numpy as np
+from PIL import Image
+
+from torch.utils.data import Dataset
+
+DEFAULT_VOID_LABELS = (0, 1, 2, 3, 4, 5, 6, 9, 10, 14, 15, 16, 18, 29, 30, -1)
+DEFAULT_VALID_LABELS = (7, 8, 11, 12, 13, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 31, 32, 33)
+
+
+class KittiDataset(Dataset):
+    """
+    Note: You need to have downloaded the Kitti dataset first and provide the path to where it is saved.
+    You can download the dataset here: http://www.cvlibs.net/datasets/kitti/eval_semseg.php?benchmark=semantics2015
+
+    There are 34 classes, however not all of them are useful for training (e.g. railings on highways). These
+    useless classes (the pixel values of these classes) are stored in `void_labels`. Useful classes are stored
+    in `valid_labels`.
+
+    The `encode_segmap` function sets all pixels with any of the `void_labels` to `ignore_index`
+    (250 by default). It also sets all of the valid pixels to the appropriate value between 0 and
+    `len(valid_labels)` (since that is the number of valid classes), so it can be used properly by
+    the loss function when comparing with the output.
+
+    Args:
+        data_dir (str): where to load the data from path, i.e. '/path/to/folder/with/data_semantics/'
+        img_size: image dimensions (width, height)
+        void_labels: useless classes to be excluded from training
+        valid_labels: useful classes to include
+    """
+    IMAGE_PATH = os.path.join('training', 'image_2')
+    MASK_PATH = os.path.join('training', 'semantic')
+
+    def __init__(
+            self,
+            data_dir: str,
+            img_size: tuple = (1242, 376),
+            void_labels: list = DEFAULT_VOID_LABELS,
+            valid_labels: list = DEFAULT_VALID_LABELS,
+            transform=None
+    ):
+        self.img_size = img_size
+        self.void_labels = void_labels
+        self.valid_labels = valid_labels
+        self.ignore_index = 250
+        self.class_map = dict(zip(self.valid_labels, range(len(self.valid_labels))))
+        self.transform = transform
+
+        self.data_dir = data_dir
+        self.img_path = os.path.join(self.data_dir, self.IMAGE_PATH)
+        self.mask_path = os.path.join(self.data_dir, self.MASK_PATH)
+        self.img_list = self.get_filenames(self.img_path)
+        self.mask_list = self.get_filenames(self.mask_path)
+
+    def __len__(self):
+        return len(self.img_list)
+
+    def __getitem__(self, idx):
+        img = Image.open(self.img_list[idx])
+        img = img.resize(self.img_size)
+        img = np.array(img)
+
+        mask = Image.open(self.mask_list[idx]).convert('L')
+        mask = mask.resize(self.img_size)
+        mask = np.array(mask)
+        mask = self.encode_segmap(mask)
+
+        if self.transform:
+            img = self.transform(img)
+
+        return img, mask
+
+    def encode_segmap(self, mask):
+        """
+        Sets void classes to zero so they won't be considered for training
+        """
+        for voidc in self.void_labels:
+            mask[mask == voidc] = self.ignore_index
+        for validc in self.valid_labels:
+            mask[mask == validc] = self.class_map[validc]
+        # remove extra idxs from updated dataset
+        mask[mask > 18] = self.ignore_index
+        return mask
+
+    def get_filenames(self, path):
+        """
+        Returns a list of absolute paths to images inside given `path`
+        """
+        files_list = list()
+        for filename in os.listdir(path):
+            files_list.append(os.path.join(path, filename))
+        return files_list