Description

Implemented a DataAnalyzer class to encapsulate data analysis module. As the beginning part of the auto3d/automl pipeline, the module shall find data and label from user inputs and generate a summary (dictionary) of data stats. The summary includes
- file names, list, number of files;
- dataset summary (basic information, image dimensions, number of classes, etc.);
- individual data information (spacing, image size, number and size of the regions, etc.).
The summary can be exported as a YAML file and a dictionary variable for use in Python

Example Usage:

from monai.apps.auto3d.data_analyzer import DataAnalyzer

datalist = {
    "testing": [{"image": "image_003.nii.gz"}],
    "training": [
        {"fold": 0, "image": "image_001.nii.gz", "label": "label_001.nii.gz"},
        {"fold": 0, "image": "image_002.nii.gz", "label": "label_002.nii.gz"},
        {"fold": 1, "image": "image_001.nii.gz", "label": "label_001.nii.gz"},
        {"fold": 1, "image": "image_004.nii.gz", "label": "label_004.nii.gz"},
    ],
}

dataroot = '/datasets' # the directory where you have the image files (in this example we're using nii.gz)
analyser = DataAnalyzer(datalist, dataroot)
datastat = analyser.get_all_case_stats() # it will also generate a data_stats.yaml that saves the stats

Status

Ready for Review
Reference issue #4743.

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• New tests added to cover the changes.
• Quick tests passed locally by running ./runtests.sh --quick --unittests --disttests.
• In-line docstrings updated.
• Documentation updated, tested make html command in the docs/ folder.