You need to create a file named ".nomedia" and place it IN that folder. Then anything you put in that folder will not appear in the gallery
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery? Forbid it, Almighty God! I know not what course others may take; but as for me, give me liberty or give me death!"
-Patrick Henry, March 23, 1775