Blur is a fairly expensive operation, and render in image is pretty
heavy as well. I would recommend checking out this example of using
core image:
/Developer/Examples/Quartz Composer/Core Image Compositions/Star
Shine.qtz
Render in image is only expensive because the default is to render in
image at screen resolution. (0x0)
If you're doing a blur you can drop the resolution of the "render in
image".
Try render in image at 640x480 then scale back to screen res, it
should be much faster and still
look ok.
