I installed the SimpleCv on my raspberryPi and the driver to use the camera board with it (uv4l driver) and now I'd like to play with it. 
When I type on simpleCV shell "Camera(0).getImage().save("foo.jpg") " , on the screen appears the camera preview and I am not able to type other command because this preview covers the shell
What Have I to do to remove the camera preview ? 
Thanks a lot !
Filippo
Try the nopreview option
pkill uv4l
uv4l --driver raspicam --auto-video_nr --encoding yuv420 --width 320 --height 240 --nopreview
export LD_PRELOAD=/usr/lib/uv4l/uv4lext/armv6l/libuv4lext.so
Hope that helps
How remove camera preview to raspberry pi