Add SBU Captioned Photo Dataset (#665)

* Add SBU Captioned Photo Dataset

* Add SBU to the dataset docs

docs/source/datasets.rst

@@ -129,3 +129,12 @@ PhotoTour
 .. autoclass:: PhotoTour
   :members: __getitem__
   :special-members:
+
+SBU
+~~~
+
+
+.. autoclass:: SBU
+  :members: __getitem__
+  :special-members:
+

torchvision/datasets/__init__.py

@@ -9,10 +9,11 @@ from .phototour import PhotoTour
 from .fakedata import FakeData
 from .semeion import SEMEION
 from .omniglot import Omniglot
+from .sbu import SBU
 
 __all__ = ('LSUN', 'LSUNClass',
            'ImageFolder', 'DatasetFolder', 'FakeData',
            'CocoCaptions', 'CocoDetection',
            'CIFAR10', 'CIFAR100', 'EMNIST', 'FashionMNIST',
            'MNIST', 'STL10', 'SVHN', 'PhotoTour', 'SEMEION',
-           'Omniglot')
+           'Omniglot', 'SBU')

torchvision/datasets/sbu.py

+from PIL import Image
+from six.moves import zip
+from .utils import download_url, check_integrity
+
+import os
+import torch.utils.data as data
+
+
+class SBU(data.Dataset):
+    """`SBU Captioned Photo <http://www.cs.virginia.edu/~vicente/sbucaptions/>`_ Dataset.
+
+    Args:
+        root (string): Root directory of dataset where tarball
+            ``SBUCaptionedPhotoDataset.tar.gz`` exists.
+        transform (callable, optional): A function/transform that takes in a PIL image
+            and returns a transformed version. E.g, ``transforms.RandomCrop``
+        target_transform (callable, optional): A function/transform that takes in the
+            target and transforms it.
+        download (bool, optional): If True, downloads the dataset from the internet and
+            puts it in root directory. If dataset is already downloaded, it is not
+            downloaded again.
+    """
+    url = "http://www.cs.virginia.edu/~vicente/sbucaptions/SBUCaptionedPhotoDataset.tar.gz"
+    filename = "SBUCaptionedPhotoDataset.tar.gz"
+    md5_checksum = '9aec147b3488753cf758b4d493422285'
+
+    def __init__(self, root, transform=None, target_transform=None, download=True):
+        self.root = os.path.expanduser(root)
+        self.transform = transform
+        self.target_transform = target_transform
+
+        if download:
+            self.download()
+
+        if not self._check_integrity():
+            raise RuntimeError('Dataset not found or corrupted.' +
+                               ' You can use download=True to download it')
+
+        # Read the caption for each photo
+        self.photos = []
+        self.captions = []
+
+        file1 = os.path.join(self.root, 'dataset', 'SBU_captioned_photo_dataset_urls.txt')
+        file2 = os.path.join(self.root, 'dataset', 'SBU_captioned_photo_dataset_captions.txt')
+
+        for line1, line2 in zip(open(file1), open(file2)):
+            url = line1.rstrip()
+            photo = os.path.basename(url)
+            filename = os.path.join(self.root, 'dataset', photo)
+            if os.path.exists(filename):
+                caption = line2.rstrip()
+                self.photos.append(photo)
+                self.captions.append(caption)
+
+    def __getitem__(self, index):
+        """
+        Args:
+            index (int): Index
+
+        Returns:
+            tuple: (image, target) where target is a caption for the photo.
+        """
+        filename = os.path.join(self.root, 'dataset', self.photos[index])
+        img = Image.open(filename).convert('RGB')
+        if self.transform is not None:
+            img = self.transform(img)
+
+        target = self.captions[index]
+        if self.target_transform is not None:
+            target = self.target_transform(target)
+
+        return img, target
+
+    def __len__(self):
+        """The number of photos in the dataset."""
+        return len(self.photos)
+
+    def _check_integrity(self):
+        """Check the md5 checksum of the downloaded tarball."""
+        root = self.root
+        fpath = os.path.join(root, self.filename)
+        if not check_integrity(fpath, self.md5_checksum):
+            return False
+        return True
+
+    def download(self):
+        """Download and extract the tarball, and download each individual photo."""
+        import tarfile
+
+        if self._check_integrity():
+            print('Files already downloaded and verified')
+            return
+
+        download_url(self.url, self.root, self.filename, self.md5_checksum)
+
+        # Extract file
+        with tarfile.open(os.path.join(self.root, self.filename), 'r:gz') as tar:
+            tar.extractall(path=self.root)
+
+        # Download individual photos
+        with open(os.path.join(self.root, 'dataset', 'SBU_captioned_photo_dataset_urls.txt')) as fh:
+            for line in fh:
+                url = line.rstrip()
+                try:
+                    download_url(url, os.path.join(self.root, 'dataset'))
+                except OSError:
+                    # The images point to public images on Flickr.
+                    # Note: Images might be removed by users at anytime.
+                    pass

torchvision/datasets/utils.py

@@ -44,10 +44,20 @@ def makedir_exist_ok(dirpath):
             raise
 
 
-def download_url(url, root, filename, md5):
+def download_url(url, root, filename=None, md5=None):
+    """Download a file from a url and place it in root.
+
+    Args:
+        url (str): URL to download file from
+        root (str): Directory to place downloaded file in
+        filename (str): Name to save the file under. If None, use the basename of the URL
+        md5 (str): MD5 checksum of the download. If None, do not check
+    """
     from six.moves import urllib
 
     root = os.path.expanduser(root)
+    if not filename:
+        filename = os.path.basename(url)
     fpath = os.path.join(root, filename)
 
     makedir_exist_ok(root)