If you search "Disable Samsung I9100 camera sounds" on Google, there are some tutorials that tells you how to remove the camera sounds on your Samsung Galaxy S2 i9100.
The classical method: Delete five .ogg files on the folder /system/media/audio/ui/:
However, the auto-focus sound is still enabled with this method. How to completely disable the camera shutter and auto-focus sounds on your Galaxy S2 I9100? Please follow the steps below:
You need to be root to do this so if you have not gotten root yet please follow my guide to root your phone: How to root Samsung Galaxy S2 GT i9100 by one clicking.
Click Menu -> New File, enter the filename local.prop, then click OK.
Screenshot: [Disable the camera sounds on I9100] Click "New File"
Screenshot: [Disable the camera sounds on I9100] Create file local.prop
Screenshot: [Disable the camera sounds on I9100] Open local.prop in Text Editor
ro.camera.sound.forced=0
Screenshot: [Disable the camera sounds on I9100] Edit local.prop
Screenshot: [Disable the camera sounds on I9100] Set the I9100 to the silent mode
Now, launch Camera application on your Samsung Galaxy S2 I9100, all camera shutter and auto-focus sounds has been disabled.
Note: To restore sound, just delete local.prop (or set ro.camera.sound.forced=1) and then reboot.
How to disable the camera shutter and auto-focus sounds on your Samsung Galaxy S2 I9100?