How can you render an image full screen or close to it?
In the bottom left of the Render buttons (F10) are 2 buttons-- DispView and DispWin. DispView renders the image in the camera view and DispWin will render in a new window with the size determined by the render size (X, Y). Set the DispWin button and set the SizeX and SizeY to the screen size to render full screen.