Cifar10¶

class paddle.vision.datasets. Cifar10 ( data_file=None, mode='train', transform=None, download=True, backend=None ) [source]

Implementation of Cifar-10 dataset, which has 10 categories.

Parameters

• data_file (str, optional) – Path to data file, can be set None if download is True. Default None, default data path: ~/.cache/paddle/dataset/cifar

• mode (str, optional) – Either train or test mode. Default ‘train’.

• transform (Callable, optional) – transform to perform on image, None for no transform. Default: None.

• download (bool, optional) – download dataset automatically if data_file is None. Default True.

• backend (str, optional) – Specifies which type of image to be returned: PIL.Image or numpy.ndarray. Should be one of {‘pil’, ‘cv2’}. If this option is not set, will get backend from paddle.vision.get_image_backend, default backend is ‘pil’. Default: None.

Returns

Dataset. An instance of Cifar10 dataset.

Examples

import itertools
import paddle.vision.transforms as T
from paddle.vision.datasets import Cifar10


cifar10 = Cifar10()
print(len(cifar10))
# 50000

for i in range(5):  # only show first 5 images
    img, label = cifar10[i]
    # do something with img and label
    print(type(img), img.size, label)
    # <class 'PIL.Image.Image'> (32, 32) 6


transform = T.Compose(
    [
        T.Resize(64),
        T.ToTensor(),
        T.Normalize(
            mean=[0.5, 0.5, 0.5],
            std=[0.5, 0.5, 0.5],
            to_rgb=True,
        ),
    ]
)

cifar10_test = Cifar10(
    mode="test",
    transform=transform,  # apply transform to every image
    backend="cv2",  # use OpenCV as image transform backend
)
print(len(cifar10_test))
# 10000

for img, label in itertools.islice(iter(cifar10_test), 5):  # only show first 5 images
    # do something with img and label
    print(type(img), img.shape, label)
    # <class 'paddle.Tensor'> [3, 64, 64] 3