No matter you are using Android phone or iPhone , as far as I know, the simple deletion will not far enough to completely erase your phone data from Android or iPhone , they still be recovered by some recovery applications, I suggest you try Safewiper program to delete photos from iPad, iPod or Android phone , there are a 2 links that you can click it .
http://www.erasephone.com/tutorials/wipe-android-data-completely.html
http://www.erasephone.com/tutorials/delete-everything-from-iphone-ipad-ipod.html