# fiftyone.utils.caltech Utilities for working with the `Caltech 101 ` and `Caltech 256 ` datasets. Copyright 2017-2026, Voxel51, Inc.
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**Functions:** | [`download_caltech101_dataset`](#fiftyone.utils.caltech.download_caltech101_dataset)(dataset_dir[, ...]) | Downloads the Caltech 101 dataset. | |------------------------------------------------------------------------------------------------------------|--------------------------------------| | [`download_caltech256_dataset`](#fiftyone.utils.caltech.download_caltech256_dataset)(dataset_dir[, ...]) | Downloads the Caltech 256 dataset. | ### fiftyone.utils.caltech.download_caltech101_dataset(dataset_dir, scratch_dir=None) Downloads the Caltech 101 dataset. See [this page](../user_guide/import_datasets.md#imageclassificationdirectorytree-import) for the format in which `dataset_dir` will be arranged. * **Parameters:** * **dataset_dir** – the directory in which to construct the dataset * **scratch_dir** (*None*) – a scratch directory to use to download any necessary temporary files * **Returns:** - num_samples: the total number of downloaded images - classes: the list of all classes - did_download: whether any content was downloaded (True) or if all necessary files were already downloaded (False) * **Return type:** a tuple of ### fiftyone.utils.caltech.download_caltech256_dataset(dataset_dir, scratch_dir=None) Downloads the Caltech 256 dataset. See [this page](../user_guide/import_datasets.md#imageclassificationdirectorytree-import) for the format in which `dataset_dir` will be arranged. * **Parameters:** * **dataset_dir** – the directory in which to construct the dataset * **scratch_dir** (*None*) – a scratch directory to use to download any necessary temporary files * **Returns:** - num_samples: the total number of downloaded images - classes: the list of all classes - did_download: whether any content was downloaded (True) or if all necessary files were already downloaded (False) * **Return type:** a tuple of