It looks like you are using the auto focus feature of the cam. Sometimes the cameras aren't smart enough to figure out what you want to focus on and pick the wrong area.
2 ways around it.
If possible, use manual focus to pick exactly what you want to focus on
or,
If you are stuck using auto focus, the trick is to find an object that is the same distance away from the lense as the the object you are trying to shoot. Focus on it by pressing the shutter halfway, keep holding the shutter halfway, then take a pic of the object you want.
If you knew this then forget I said anything.