Nichtbildbereiche

Nichtbildbereiche are portions of an image or data set that do not contain image information. They appear as uniform margins or blank regions outside the region where the imaged signal is captured. The term is used across imaging disciplines, including radiology, photography, microscopy, and remote sensing, to refer to parts of the data that should not be interpreted as content.

Causes of Nichtbildbereiche include limitations of the field of view, cropping during acquisition, masking of sensitive areas, sensor dead zones, or data loss during transfer. In medical imaging, such regions often arise from beam collimation and gantry geometry that exclude areas outside the patient, or from reconstruction padding. In digital photography and microscopy, they can result from lens vignetting, sensor boundaries, or intentional masking.

Handling involves recognizing and excluding these regions from analysis, cropping images consistently, or applying masks. In quantitative work, Nichtbildbereiche should be documented, with information about the field of view, pixel size, and any padding noted. If necessary, padding can be filled with neutral values, but this should be distinguished from true image content to avoid bias.

Labeling and documentation are important, especially when comparing images from different sessions or modalities. Proper management of Nichtbildbereiche improves measurement accuracy and prevents misinterpretation of borders as features.