Out of the many label types available in DicomObjects.NET, LabelType.Image can be used to directly reference a System.Drawing.Image object (jpg, png, bmp, etc) and to be rendered as a DicomLabel on the viewer.

Example code snippet:

 Viewer.Labels.Add(new DicomLabel()
 {
	LabelType = LabelType.Image,
	Image = Image.FromFile("Sample.jpg"),
	Left = 100,
	Top = 100,
	Width = 100,
	Height = 100,
	ScaleMode = ScaleMode.Output
 });