Solution 1: Fix the camera application
Opens the general settings of your Android (slide down the top bar on the screen and tap on the figure of a gear). Then, choose Applications Manager> All> House and there touches on the "Force Stop" button. It also touches on the "Clear Cache" button and "Clear data". Reboot your phone and check if the camera is fixed.
Solution 2: Clear the cache partition
Turn off your phone. Once off, then hold the same buttons Volume Up, Power and Home. When the phone vibrates, release the Power button but do not release the other two. You will enter a special mode called Galaxy Samsung "Recovery". There lies the "Wipe Cache Partition" option with the volume down button, select this option with the power button.