Differences with torchvision.datasets.VOCSegmentation

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torchvision.datasets.VOCSegmentation

class torchvision.datasets.VOCSegmentation(
    root: str,
    year: str='2012',
    image_set: str='train',
    download: bool=False,
    transform: Optional[Callable]=None,
    target_transform: Optional[Callable]=None,
    transforms: Optional[Callable]=None
    )

For more information, see torchvision.datasets.VOCSegmentation.

mindspore.dataset.VOCDataset

class mindspore.dataset.VOCDataset(
    dataset_dir,
    task="Segmentation",
    usage="train",
    class_indexing=None,
    num_samples=None,
    num_parallel_workers=None,
    shuffle=None,
    decode=False,
    sampler=None,
    num_shards=None,
    shard_id=None,
    cache=None,
    extra_metadata=False,
    decrypt=None
    )

For more information, see mindspore.dataset.VOCDataset.

Differences

PyTorch: Pascal VOC Segmentation Dataset.

MindSpore: A source dataset for reading and parsing VOC dataset.

Categories

Subcategories

PyTorch

MindSpore

Difference

Parameter

Parameter1

root

dataset_dir

-

Parameter2

year

-

Not supported by MindSpore

Parameter3

image_set

usage

-

Parameter4

download

-

Not supported by MindSpore

Parameter5

transform

-

Supported by mindspore.dataset.map operation

Parameter6

target_transform

-

Supported by mindspore.dataset.map operation

Parameter7

transforms

-

Supported by mindspore.dataset.map operation

Parameter8

-

task

Set the task type of reading voc data

Parameter9

-

class_indexing

A str-to-int mapping from label name to index

Parameter10

-

num_samples

The number of images to be included in the dataset

Parameter11

-

num_parallel_workers

Number of worker threads to read the data

Parameter12

-

shuffle

Whether to perform shuffle on the dataset

Parameter13

-

decode

Whether to decode the images after reading

Parameter14

-

sampler

Object used to choose samples from the dataset

Parameter15

-

num_shards

Number of shards that the dataset will be divided into

Parameter16

-

shard_id

The shard ID within num_shards

Parameter17

-

cache

Use tensor caching service to speed up dataset processing

Parameter18

-

extra_metadata

Flag to add extra meta-data to row

Parameter19

-

decrypt

Image decryption function

Code Example

import mindspore.dataset as ds
import torchvision.transforms as T
import torchvision.datasets as datasets
from torch.utils.data import DataLoader

# In MindSpore, the generated dataset with different task setting has different output columns.

voc_dataset_dir = "/path/to/voc_dataset_directory/"

# task = Segmentation, output columns: [image, dtype=uint8], [target,dtype=uint8].
dataset = ds.VOCDataset(dataset_dir=voc_dataset_dir,
                                                    task="Segmentation",
                                                    usage="train")
for item in dataset:
    print("item:", item[0])
    print(len(item[0]))
    break
# Out:
# item: [255 216 255 ...  73 255 217]
# 52544

# In torch, the output will be result of transform, eg. RandomCrop
root = "/path/to/voc_dataset_directory2/"

dataset = datasets.VOCSegmentation(root, image_set='train', year='2012', transform=T.RandomCrop(300))
print(dataset)
print(type(dataset))