CvSize does not exist?
The right call is cv.cvSize(inp.width/2, inp.height/2). 
All functions in the python opencv bindings start with a lowercased c even in the highgui module.
I have installed the official python bindings for OpenCv and I am implementing some standard textbook functions just to get used to the python syntax.  I have run into the problem, however, that CvSize does not actually exist, even though it is documented on the site...  
The simple function: blah = cv.CvSize(inp.width/2, inp.height/2) yields the error 'module' object has no attribute 'CvSize'.  I have imported with 'import cv'.
Is there an equivalent structure?  Do I need something more?  Thanks.