API to set the css dimensions of the canvas elements without changing the element height/width [possible feature]

See it on action:
http://jsfiddle.net/Bnaya/VzwZ6/
The code isn't ready of course , its only a demo.

My use case for that feature:
Photo editor on a small screen/resized browser window and i want to keep the photo resources on the original resolution, or not to change the actual canvas size every browser resize and lose data.