Faster RCNN Model + Pascal VOC DataModule (#157)

* VOCDetection DataModule

* faster_rcnn

* fixed vocdetection dataset

* Faster RCNN, Pascal VOC complete

* pep8 docs fix

* added dummy detection dataset and testing fasterrcnn training

* Update pl_bolts/models/detection/faster_rcnn.py

Co-authored-by: Jirka Borovec <Borda@users.noreply.github.com>

* fix pep8

* Change torchvision >= 0.7

Co-authored-by: Jirka Borovec <Borda@users.noreply.github.com>

pl_bolts/datamodules/__init__.py

@@ -1,12 +1,24 @@
 from pl_bolts.datamodules.async_dataloader import AsynchronousLoader
-from pl_bolts.datamodules.cifar10_datamodule import CIFAR10DataModule, TinyCIFAR10DataModule
-from pl_bolts.datamodules.dummy_dataset import DummyDataset
-from pl_bolts.datamodules.experience_source import (ExperienceSourceDataset, ExperienceSource,
-                                                    DiscountedExperienceSource)
+from pl_bolts.datamodules.cifar10_datamodule import (
+    CIFAR10DataModule,
+    TinyCIFAR10DataModule,
+)
+from pl_bolts.datamodules.dummy_dataset import DummyDataset, DummyDetectionDataset
+from pl_bolts.datamodules.experience_source import (
+    ExperienceSourceDataset,
+    ExperienceSource,
+    DiscountedExperienceSource,
+)
 from pl_bolts.datamodules.fashion_mnist_datamodule import FashionMNISTDataModule
 from pl_bolts.datamodules.imagenet_datamodule import ImagenetDataModule
 from pl_bolts.datamodules.mnist_datamodule import MNISTDataModule
 from pl_bolts.datamodules.binary_mnist_datamodule import BinaryMNISTDataModule
-from pl_bolts.datamodules.sklearn_datamodule import SklearnDataset, SklearnDataModule, TensorDataset, TensorDataModule
+from pl_bolts.datamodules.sklearn_datamodule import (
+    SklearnDataset,
+    SklearnDataModule,
+    TensorDataset,
+    TensorDataModule,
+)
 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

pl_bolts/datamodules/dummy_dataset.py

@@ -3,7 +3,6 @@
 
 
 class DummyDataset(Dataset):
-
     def __init__(self, *shapes, num_samples=10000):
         """
         Generate a dummy dataset
@@ -41,3 +40,29 @@ def __getitem__(self, idx):
             samples.append(sample)
 
         return samples
+
+
+class DummyDetectionDataset(Dataset):
+    def __init__(
+        self, img_shape=(3, 256, 256), num_boxes=1, num_classes=2, num_samples=10000
+    ):
+        super().__init__()
+        self.img_shape = img_shape
+        self.num_samples = num_samples
+        self.num_boxes = num_boxes
+        self.num_classes = num_classes
+
+    def __len__(self):
+        return self.num_samples
+
+    def _random_bbox(self):
+        c, h, w = self.img_shape
+        xs = torch.randint(w, (2,))
+        ys = torch.randint(h, (2,))
+        return [min(xs), min(ys), max(xs), max(ys)]
+
+    def __getitem__(self, idx):
+        img = torch.rand(self.img_shape)
+        boxes = torch.tensor([self._random_bbox() for _ in range(self.num_boxes)])
+        labels = torch.randint(self.num_classes, (self.num_boxes,))
+        return img, {"boxes": boxes, "labels": labels}

pl_bolts/datamodules/vocdetection_datamodule.py

@@ -0,0 +1,199 @@
+import torch
+from pytorch_lightning import LightningDataModule
+from torch.utils.data import DataLoader
+from torchvision.datasets import VOCDetection
+import torchvision.transforms as T
+
+
+class Compose(object):
+    """
+    Like `torchvision.transforms.compose` but works for (image, target)
+    """
+
+    def __init__(self, transforms):
+        self.transforms = transforms
+
+    def __call__(self, image, target):
+        for t in self.transforms:
+            image, target = t(image, target)
+        return image, target
+
+
+def _collate_fn(batch):
+    return tuple(zip(*batch))
+
+
+CLASSES = (
+    "__background__ ",
+    "aeroplane",
+    "bicycle",
+    "bird",
+    "boat",
+    "bottle",
+    "bus",
+    "car",
+    "cat",
+    "chair",
+    "cow",
+    "diningtable",
+    "dog",
+    "horse",
+    "motorbike",
+    "person",
+    "pottedplant",
+    "sheep",
+    "sofa",
+    "train",
+    "tvmonitor",
+)
+
+
+def _prepare_voc_instance(image, target):
+    """
+    Prepares VOC dataset into appropriate target for fasterrcnn
+
+    https://github.com/pytorch/vision/issues/1097#issuecomment-508917489
+    """
+    anno = target["annotation"]
+    h, w = anno["size"]["height"], anno["size"]["width"]
+    boxes = []
+    classes = []
+    area = []
+    iscrowd = []
+    objects = anno["object"]
+    if not isinstance(objects, list):
+        objects = [objects]
+    for obj in objects:
+        bbox = obj["bndbox"]
+        bbox = [int(bbox[n]) - 1 for n in ["xmin", "ymin", "xmax", "ymax"]]
+        boxes.append(bbox)
+        classes.append(CLASSES.index(obj["name"]))
+        iscrowd.append(int(obj["difficult"]))
+        area.append((bbox[2] - bbox[0]) * (bbox[3] - bbox[1]))
+
+    boxes = torch.as_tensor(boxes, dtype=torch.float32)
+    classes = torch.as_tensor(classes)
+    area = torch.as_tensor(area)
+    iscrowd = torch.as_tensor(iscrowd)
+
+    image_id = anno["filename"][5:-4]
+    image_id = torch.as_tensor([int(image_id)])
+
+    target = {}
+    target["boxes"] = boxes
+    target["labels"] = classes
+    target["image_id"] = image_id
+
+    # for conversion to coco api
+    target["area"] = area
+    target["iscrowd"] = iscrowd
+
+    return image, target
+
+
+class VOCDetectionDataModule(LightningDataModule):
+    name = "vocdetection"
+
+    def __init__(
+        self,
+        data_dir: str,
+        year: str = "2012",
+        num_workers: int = 16,
+        normalize: bool = False,
+        *args,
+        **kwargs,
+    ):
+        """
+        TODO(teddykoker) docstring
+        """
+
+        super().__init__(*args, **kwargs)
+        self.year = year
+        self.data_dir = data_dir
+        self.num_workers = num_workers
+        self.normalize = normalize
+
+    @property
+    def num_classes(self):
+        """
+        Return:
+            21
+        """
+        return 21
+
+    def prepare_data(self):
+        """
+        Saves VOCDetection files to data_dir
+        """
+        VOCDetection(self.data_dir, year=self.year, image_set="train", download=True)
+        VOCDetection(self.data_dir, year=self.year, image_set="val", download=True)
+
+    def train_dataloader(self, batch_size=1, transforms=None):
+        """
+        VOCDetection train set uses the `train` subset
+
+        Args:
+            batch_size: size of batch
+            transforms: custom transforms
+        """
+        t = [_prepare_voc_instance]
+        transforms = transforms or self.train_transforms or self._default_transforms()
+        if transforms is not None:
+            t.append(transforms)
+        transforms = Compose(t)
+
+        dataset = VOCDetection(
+            self.data_dir, year=self.year, image_set="train", transforms=transforms
+        )
+        loader = DataLoader(
+            dataset,
+            batch_size=batch_size,
+            shuffle=True,
+            num_workers=self.num_workers,
+            pin_memory=True,
+            collate_fn=_collate_fn,
+        )
+        return loader
+
+    def val_dataloader(self, batch_size=1, transforms=None):
+        """
+        VOCDetection val set uses the `val` subset
+
+        Args:
+            batch_size: size of batch
+            transforms: custom transforms
+        """
+        t = [_prepare_voc_instance]
+        transforms = transforms or self.val_transforms or self._default_transforms()
+        if transforms is not None:
+            t.append(transforms)
+        transforms = Compose(t)
+        dataset = VOCDetection(
+            self.data_dir, year=self.year, image_set="val", transforms=transforms
+        )
+        loader = DataLoader(
+            dataset,
+            batch_size=batch_size,
+            shuffle=False,
+            num_workers=self.num_workers,
+            pin_memory=True,
+            collate_fn=_collate_fn,
+        )
+        return loader
+
+    def _default_transforms(self):
+        if self.normalize:
+            return (
+                lambda image, target: (
+                    T.Compose(
+                        [
+                            T.ToTensor(),
+                            T.Normalize(
+                                mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]
+                            ),
+                        ]
+                    )(image),
+                    target,
+                ),
+            )
+        return lambda image, target: (T.ToTensor()(image), target)

pl_bolts/models/detection/__init__.py

@@ -0,0 +1 @@
+from pl_bolts.models.detection.faster_rcnn import FasterRCNN