| """ A dataset reader that reads single tarfile based datasets |
| |
| This reader can read datasets consisting if a single tarfile containing images. |
| I am planning to deprecated it in favour of ParerImageInTar. |
| |
| Hacked together by / Copyright 2020 Ross Wightman |
| """ |
| import os |
| import tarfile |
|
|
| from timm.utils.misc import natural_key |
|
|
| from .class_map import load_class_map |
| from .img_extensions import get_img_extensions |
| from .reader import Reader |
|
|
|
|
| def extract_tarinfo(tarfile, class_to_idx=None, sort=True): |
| extensions = get_img_extensions(as_set=True) |
| files = [] |
| labels = [] |
| for ti in tarfile.getmembers(): |
| if not ti.isfile(): |
| continue |
| dirname, basename = os.path.split(ti.path) |
| label = os.path.basename(dirname) |
| ext = os.path.splitext(basename)[1] |
| if ext.lower() in extensions: |
| files.append(ti) |
| labels.append(label) |
| if class_to_idx is None: |
| unique_labels = set(labels) |
| sorted_labels = list(sorted(unique_labels, key=natural_key)) |
| class_to_idx = {c: idx for idx, c in enumerate(sorted_labels)} |
| tarinfo_and_targets = [(f, class_to_idx[l]) for f, l in zip(files, labels) if l in class_to_idx] |
| if sort: |
| tarinfo_and_targets = sorted(tarinfo_and_targets, key=lambda k: natural_key(k[0].path)) |
| return tarinfo_and_targets, class_to_idx |
|
|
|
|
| class ReaderImageTar(Reader): |
| """ Single tarfile dataset where classes are mapped to folders within tar |
| NOTE: This class is being deprecated in favour of the more capable ReaderImageInTar that can |
| operate on folders of tars or tars in tars. |
| """ |
| def __init__(self, root, class_map=''): |
| super().__init__() |
|
|
| class_to_idx = None |
| if class_map: |
| class_to_idx = load_class_map(class_map, root) |
| assert os.path.isfile(root) |
| self.root = root |
|
|
| with tarfile.open(root) as tf: |
| self.samples, self.class_to_idx = extract_tarinfo(tf, class_to_idx) |
| self.imgs = self.samples |
| self.tarfile = None |
|
|
| def __getitem__(self, index): |
| if self.tarfile is None: |
| self.tarfile = tarfile.open(self.root) |
| tarinfo, target = self.samples[index] |
| fileobj = self.tarfile.extractfile(tarinfo) |
| return fileobj, target |
|
|
| def __len__(self): |
| return len(self.samples) |
|
|
| def _filename(self, index, basename=False, absolute=False): |
| filename = self.samples[index][0].name |
| if basename: |
| filename = os.path.basename(filename) |
| return filename |
|
|
