title: Binding Size of Canvas Background
body: <p>I have a canvas that needs a graphical background using custom images of various sizes, but I want to bind the height and width of the background image to some properties somewhere. right now I have an image displaying as background but its size is fixed. It turns out that the width and height property of the image and of the imagebrush is readonly. Is there anyway to bind the width and height?</p>
  
  <p>p.s I have tried viewport, but it uses a rect object and its width and height are not dependency properties. Then I tried to use one tile of the viewport and put it in a rectangle then I can resize the rectangle to achieve what I want but I cannot figure out how to put a rectangle as the canvas's background. Any Ideas? Thanks in advance.</p>