Image zip#

Format specification#

The image zip format allows to export/import unannotated datasets with images to/from a zip archive. The format doesn’t support any annotations or attributes.

Convert Image zip dataset#

There are several ways to convert unannotated datasets with Datumaro:

From an existing archive:

datum convert --input-format image_zip --input-path ./images.zip \
    --output-format <desired_format> --output-dir <output/dir>

From a directory with zip archives. Datumaro will convert images from all zip files in the directory:

datum convert --input-format image_zip --input-path ./foo \
    --output-format <desired_format> --output-dir <output/dir>

The directory with zip archives must have the following structure:

└── foo/
    ├── archive1.zip/
    |   ├── image_1.jpg
    |   ├── image_2.png
    |   ├── subdir/
    |   |   ├── image_3.jpg
    |   |   └── ...
    |   └── ...
    ├── archive2.zip/
    |   ├── image_101.jpg
    |   ├── image_102.jpg
    |   └── ...
    ...

Images in the archives must have a supported extension, follow the media format to see the supported extensions.

Export to other formats#

Datumaro can convert image zip dataset into any other format Datumaro supports. For example:

datum convert -if image_zip -i ./images.zip -f coco -o ./new_dir -- --save-media

Or, using Python API:

import datumaro as dm

dataset = dm.Dataset.import_from('<path/to/dataset>', 'image_zip')
dataset.export('save_dir', 'coco', save_media=True)

Export an unannotated dataset to a zip archive#

Example: converting images from a VOC dataset to zip archives:

datum convert -if voc -i ./VOC2012 -f image_zip -o ./output_dir -- --name voc_images.zip

Extra options for exporting to image_zip format:

--save-media allow to export dataset with saving media files (default: False)
--image-ext <IMAGE_EXT> allow to specify image extension for exporting dataset (default: use original or .jpg, if none)
--name name of output zipfile (default: default.zip)
--compression allow to specify archive compression method. Available methods: ZIP_STORED, ZIP_DEFLATED, ZIP_BZIP2, ZIP_LZMA (default: ZIP_STORED). Follow zip documentation for more information.

Examples#

Examples of using this format from the code can be found in the format tests