How can I resize/move the "canvas" of an image in the compositor? As you can see, if I try to translate an image in the compositor, it does not affect the actual bounds of the image, only the pixels themselves. 





The same thing happens when trying to scale an image:



So the image cannot be moved or scaled further than the actual dimensions of the image without clipping it.

The render border size does not seem to affect it: (Seen here with a gradient texture to define where the render dimensions are.)



For some reason skipping the blur node makes it work, but with it it gets cropped.

Aside from creating a lot of transparent space around the image in an external image editor or scaling the Pixels down with a Scale node,
How can I accomplish this?
There was a bug report on this where Ton said:


  Blender compositor is an extension of our render pipeline, animation frames by definition are always the same size.
  
  This is an issue we like to work on though, it's called "Canvas awareness" for compositor, where you can define a different output size for it than renders, and transform the renders inside the canvas freely.


There's currently two options:


Perform transforms in 3D and used to resulting render layer. The planes from images addon can help with the setup.
Perform a composite operation against an image of the desired size. The easiest way to generate one, is using the Mask node with a Fixed size.