remove decoding from prototype datasets (#5287)

* remove decoder from prototype datasets

* remove unused imports

* cleanup

* fix readme

* use OneHotLabel in SEMEION

* improve voc implementation

* revert unrelated changes

* fix semeion mock data

Author: pmeier

test/builtin_dataset_mocks.py

@@ -431,50 +431,52 @@ def caltech256(info, root, config):
 
 @register_mock
 def imagenet(info, root, config):
-    wnids = tuple(info.extra.wnid_to_category.keys())
-    if config.split == "train":
-        images_root = root / "ILSVRC2012_img_train"
+    from scipy.io import savemat
 
+    categories = info.categories
+    wnids = [info.extra.category_to_wnid[category] for category in categories]
+    if config.split == "train":
         num_samples = len(wnids)
+        archive_name = "ILSVRC2012_img_train.tar"
 
+        files = []
         for wnid in wnids:
-            files = create_image_folder(
-                root=images_root,
+            create_image_folder(
+                root=root,
                 name=wnid,
                 file_name_fn=lambda image_idx: f"{wnid}_{image_idx:04d}.JPEG",
                 num_examples=1,
             )
-            make_tar(images_root, f"{wnid}.tar", files[0].parent)
+            files.append(make_tar(root, f"{wnid}.tar"))
     elif config.split == "val":
         num_samples = 3
-        files = create_image_folder(
-            root=root,
-            name="ILSVRC2012_img_val",
-            file_name_fn=lambda image_idx: f"ILSVRC2012_val_{image_idx + 1:08d}.JPEG",
-            num_examples=num_samples,
-        )
-        images_root = files[0].parent
-    else:  # config.split == "test"
-        images_root = root / "ILSVRC2012_img_test_v10102019"
+        archive_name = "ILSVRC2012_img_val.tar"
+        files = [create_image_file(root, f"ILSVRC2012_val_{idx + 1:08d}.JPEG") for idx in range(num_samples)]
 
-        num_samples = 3
+        devkit_root = root / "ILSVRC2012_devkit_t12"
+        data_root = devkit_root / "data"
+        data_root.mkdir(parents=True)
 
-        create_image_folder(
-            root=images_root,
-            name="test",
-            file_name_fn=lambda image_idx: f"ILSVRC2012_test_{image_idx + 1:08d}.JPEG",
-            num_examples=num_samples,
-        )
-    make_tar(root, f"{images_root.name}.tar", images_root)
+        with open(data_root / "ILSVRC2012_validation_ground_truth.txt", "w") as file:
+            for label in torch.randint(0, len(wnids), (num_samples,)).tolist():
+                file.write(f"{label}\n")
+
+        num_children = 0
+        synsets = [
+            (idx, wnid, category, "", num_children, [], 0, 0)
+            for idx, (category, wnid) in enumerate(zip(categories, wnids), 1)
+        ]
+        num_children = 1
+        synsets.extend((0, "", "", "", num_children, [], 0, 0) for _ in range(5))
+        savemat(data_root / "meta.mat", dict(synsets=synsets))
+
+        make_tar(root, devkit_root.with_suffix(".tar.gz").name, compression="gz")
+    else:  # config.split == "test"
+        num_samples = 5
+        archive_name = "ILSVRC2012_img_test_v10102019.tar"
+        files = [create_image_file(root, f"ILSVRC2012_test_{idx + 1:08d}.JPEG") for idx in range(num_samples)]
 
-    devkit_root = root / "ILSVRC2012_devkit_t12"
-    devkit_root.mkdir()
-    data_root = devkit_root / "data"
-    data_root.mkdir()
-    with open(data_root / "ILSVRC2012_validation_ground_truth.txt", "w") as file:
-        for label in torch.randint(0, len(wnids), (num_samples,)).tolist():
-            file.write(f"{label}\n")
-    make_tar(root, f"{devkit_root}.tar.gz", devkit_root, compression="gz")
+    make_tar(root, archive_name, *files)
 
     return num_samples
 
@@ -666,14 +668,15 @@ def sbd(info, root, config):
 @register_mock
 def semeion(info, root, config):
     num_samples = 3
+    num_categories = len(info.categories)
 
     images = torch.rand(num_samples, 256)
-    labels = one_hot(torch.randint(len(info.categories), size=(num_samples,)))
+    labels = one_hot(torch.randint(num_categories, size=(num_samples,)), num_classes=num_categories)
     with open(root / "semeion.data", "w") as fh:
         for image, one_hot_label in zip(images, labels):
             image_columns = " ".join([f"{pixel.item():.4f}" for pixel in image])
             labels_columns = " ".join([str(label.item()) for label in one_hot_label])
-            fh.write(f"{image_columns} {labels_columns}\n")
+            fh.write(f"{image_columns} {labels_columns} \n")
 
     return num_samples
 
@@ -728,32 +731,33 @@ def _make_detection_anns_folder(cls, root, name, *, file_name_fn, num_examples):
     def _make_detection_ann_file(cls, root, name):
         def add_child(parent, name, text=None):
             child = ET.SubElement(parent, name)
-            child.text = text
+            child.text = str(text)
             return child
 
         def add_name(obj, name="dog"):
             add_child(obj, "name", name)
-            return name
 
-        def add_bndbox(obj, bndbox=None):
-            if bndbox is None:
-                bndbox = {"xmin": "1", "xmax": "2", "ymin": "3", "ymax": "4"}
+        def add_size(obj):
+            obj = add_child(obj, "size")
+            size = {"width": 0, "height": 0, "depth": 3}
+            for name, text in size.items():
+                add_child(obj, name, text)
 
+        def add_bndbox(obj):
             obj = add_child(obj, "bndbox")
+            bndbox = {"xmin": 1, "xmax": 2, "ymin": 3, "ymax": 4}
             for name, text in bndbox.items():
                 add_child(obj, name, text)
 
-            return bndbox
-
         annotation = ET.Element("annotation")
+        add_size(annotation)
         obj = add_child(annotation, "object")
-        data = dict(name=add_name(obj), bndbox=add_bndbox(obj))
+        add_name(obj)
+        add_bndbox(obj)
 
         with open(root / name, "wb") as fh:
             fh.write(ET.tostring(annotation))
 
-        return data
-
     @classmethod
     def generate(cls, root, *, year, trainval):
         archive_folder = root

test/test_prototype_builtin_datasets.py

@@ -1,16 +1,23 @@
+import functools
 import io
 from pathlib import Path
 
 import pytest
 import torch
 from builtin_dataset_mocks import parametrize_dataset_mocks, DATASET_MOCKS
+from torch.testing._comparison import assert_equal, TensorLikePair, ObjectPair
 from torch.utils.data.datapipes.iter.grouping import ShardingFilterIterDataPipe as ShardingFilter
 from torch.utils.data.graph import traverse
 from torchdata.datapipes.iter import IterDataPipe, Shuffler
 from torchvision.prototype import transforms, datasets
 from torchvision.prototype.utils._internal import sequence_to_str
 
 
+assert_samples_equal = functools.partial(
+    assert_equal, pair_types=(TensorLikePair, ObjectPair), rtol=0, atol=0, equal_nan=True
+)
+
+
 @pytest.fixture
 def test_home(mocker, tmp_path):
     mocker.patch("torchvision.prototype.datasets._api.home", return_value=str(tmp_path))
@@ -92,6 +99,7 @@ def test_no_vanilla_tensors(self, test_home, dataset_mock, config):
                 f"{sequence_to_str(sorted(vanilla_tensors), separate_last='and ')} contained vanilla tensors."
             )
 
+    @pytest.mark.xfail
     @parametrize_dataset_mocks(DATASET_MOCKS)
     def test_transformable(self, test_home, dataset_mock, config):
         dataset_mock.prepare(test_home, config)
@@ -137,6 +145,17 @@ def scan(graph):
         if not any(type(dp) is annotation_dp_type for dp in scan(traverse(dataset))):
             raise AssertionError(f"The dataset doesn't contain a {annotation_dp_type.__name__}() datapipe.")
 
+    @parametrize_dataset_mocks(DATASET_MOCKS)
+    def test_save_load(self, test_home, dataset_mock, config):
+        dataset_mock.prepare(test_home, config)
+        dataset = datasets.load(dataset_mock.name, **config)
+        sample = next(iter(dataset))
+
+        with io.BytesIO() as buffer:
+            torch.save(sample, buffer)
+            buffer.seek(0)
+            assert_samples_equal(torch.load(buffer), sample)
+
 
 @parametrize_dataset_mocks(DATASET_MOCKS["qmnist"])
 class TestQMNIST:
@@ -171,5 +190,5 @@ def test_label_matches_path(self, test_home, dataset_mock, config):
         dataset = datasets.load(dataset_mock.name, **config)
 
         for sample in dataset:
-            label_from_path = int(Path(sample["image_path"]).parent.name)
+            label_from_path = int(Path(sample["path"]).parent.name)
             assert sample["label"] == label_from_path

test/test_prototype_datasets_api.py

@@ -5,8 +5,8 @@
 from torchvision.prototype.utils._internal import FrozenMapping, FrozenBunch
 
 
-def make_minimal_dataset_info(name="name", type=datasets.utils.DatasetType.RAW, categories=None, **kwargs):
-    return datasets.utils.DatasetInfo(name, type=type, categories=categories or [], **kwargs)
+def make_minimal_dataset_info(name="name", categories=None, **kwargs):
+    return datasets.utils.DatasetInfo(name, categories=categories or [], **kwargs)
 
 
 class TestFrozenMapping:
@@ -176,7 +176,7 @@ def resources(self, config):
             # This method is just defined to appease the ABC, but will be overwritten at instantiation
             pass
 
-        def _make_datapipe(self, resource_dps, *, config, decoder):
+        def _make_datapipe(self, resource_dps, *, config):
             # This method is just defined to appease the ABC, but will be overwritten at instantiation
             pass
 
@@ -229,12 +229,3 @@ def test_resources(self, mocker):
 
         (call_args, _) = dataset._make_datapipe.call_args
         assert call_args[0][0] is sentinel
-
-    def test_decoder(self):
-        dataset = self.DatasetMock()
-
-        sentinel = object()
-        dataset.load("", decoder=sentinel)
-
-        (_, call_kwargs) = dataset._make_datapipe.call_args
-        assert call_kwargs["decoder"] is sentinel

test/test_prototype_transforms.py

@@ -7,7 +7,7 @@
         "Note that you cannot install it with `pip install torchdata`, since this is another package."
     ) from error
 
-from . import decoder, utils
+from . import utils
 from ._home import home
 
 # Load this last, since some parts depend on the above being loaded first

torchvision/prototype/datasets/__init__.py

@@ -1,12 +1,9 @@
-import io
 import os
-from typing import Any, Callable, Dict, List, Optional
+from typing import Any, Dict, List
 
-import torch
 from torch.utils.data import IterDataPipe
 from torchvision.prototype.datasets import home
-from torchvision.prototype.datasets.decoder import raw, pil
-from torchvision.prototype.datasets.utils import Dataset, DatasetInfo, DatasetType
+from torchvision.prototype.datasets.utils import Dataset, DatasetInfo
 from torchvision.prototype.utils._internal import add_suggestion
 
 from . import _builtin
@@ -49,27 +46,15 @@ def info(name: str) -> DatasetInfo:
     return find(name).info
 
 
-DEFAULT_DECODER = object()
-
-DEFAULT_DECODER_MAP: Dict[DatasetType, Callable[[io.IOBase], torch.Tensor]] = {
-    DatasetType.RAW: raw,
-    DatasetType.IMAGE: pil,
-}
-
-
 def load(
     name: str,
     *,
-    decoder: Optional[Callable[[io.IOBase], torch.Tensor]] = DEFAULT_DECODER,  # type: ignore[assignment]
     skip_integrity_check: bool = False,
     **options: Any,
 ) -> IterDataPipe[Dict[str, Any]]:
     dataset = find(name)
 
-    if decoder is DEFAULT_DECODER:
-        decoder = DEFAULT_DECODER_MAP.get(dataset.info.type)
-
     config = dataset.info.make_config(**options)
     root = os.path.join(home(), dataset.name)
 
-    return dataset.load(root, config=config, decoder=decoder, skip_integrity_check=skip_integrity_check)
+    return dataset.load(root, config=config, skip_integrity_check=skip_integrity_check)