A DicomLabel item represents a label, or annotation, to be displayed over an image in a DicomViewer control, or in derived copies of the image.
Labels may be ellipses (or circles), rectangles (or squares), lines, text or bitmaps, or other shapes (see LabelType for a full list), and the properties control not only the type and size of the object, but many other properties such as colour and line thickness. 

Labels may be tied to the viewer control, to the display area in which an image is displayed, or to the image itself, this latter distinction being controlled by the RotateModeWithImage property.
All properties have default values, which are suitable for many uses, and each is documented with the appropriate property.  The same label may be added into several DicomLabels collections if necessary, but where this is done, subsequent labels will be “cloned” when added, so that they may later be manipulated independently.  Also, unambiguous association of each DicomLabel with one image is necessary for the ROI functions.