Welcome to Android Central! How did you delete it--using the Gallery app, the Google Photos app, or a file manager? If you used the Google Photos app, then swipe in from the left and tap Trash--the deleted photos might be there, and might be restorable.
If you deleted using the Gallery app or the file manager, then you'll need to use some 3rd party programs to try to recover. If the pictures were stored on Internal Storage, then you have to root the phone, and it'll still be very difficult to retrieve them. See this guide:
http://forums.androidcentral.com/am...-s/500142-guide-recovering-deleted-files.html