In a WPF user control, how do I specify coordinates relative to the control's total size, so that the control will scale correctly?

Answer 1

You can put the image inside a view box, or inside a VisualBrush and use a rectangle to draw it (set the brush to the Rectangle.Fill property).

Even better, convert your image to a Drawing objects (replace Canvas with DrawingGroup and the shapes inside it with GeometryDrawing) and use DrawingBrush to paint it.