Here are a couple of solutions that hopefully may work.....
Hold power button and home button at the same time approx. 7 seconds until device powers off.
Go into settings, application manager, camera app, clear data and clear cache.
Power off device, then hold power, volume up, and home button until turn on, let go off all three, this should take you to the android system screen. Use vol up and down to select, wipe cache partition.
Hope this helped.