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* Added support for converting empty segmentation masks to an RTSS.
* Added support for color selection in :class:`~pyradise.fileio.dicom_conversion.SubjectToRTSSConverter`.
* Added a data field to each :class:`~pyradise.data.image.Image` sub-class to store additional information.
* Added an additional mechanism to all :class:`~pyradise.process.base.Filter` sub-classes to raise warnings when a non-invertible filter's operation is inverted.
* Added a hole filling algorithm to the classes for loading DICOM-RTSS files to circumvent issues with unexpected small holes in the resulting segmentation masks.
* Extended the :class:`~pyradise.fileio.modality_config.ModalityConfiguration` class to support manual addition of modality configuration entries.
* General optimization of the converter classes.
* Optimized the writing of directory hierarchies to circumvent issues during copying of multi-level hierarchies.
* Relaxed exception handling in :class:`~pyradise.fileio.series_info.DicomSeriesRegistrationInfo` to allow for more flexible handling of non-compliant DICOM registration files.
* Fixed the crawling procedure to circumvent issues with single DICOM image series loading.
* Minor updates to the documentation.